Plant ID: Epipactis sp.

Question:
Are there orchids that are native to growing in NY? I live in Buffalo and every summer have something growing in my yard that looks like an orchid. I will enclose a picture so maybe you can identify it.

Answer:
Actually there are a number of different kinds of terrestrial (meaning they grow in the ground) orchids that grow and can survive the winter here in the northeast. The orchid family, Orchidaceae, is one of the largest families, if not the largest, of flowering plants (also called angiosperms) in the world and they can be found on most continents. Some are native to North America while others have been introduced and then naturalized themselves in the landscape.

The plant you are trying to identify is in the genus Epipactis, and may very well be Epipactis helleborine, commonly called a broadleaf helleborine. I am always hesitant to swear 100% certainty as proper botanical identification can be much more of an involved process, but I am confident that we have your plant appropriately identified to genus. Helleborines are native to Europe and Asia but were introduced to the U.S. so long ago that these days they can be found in wooded areas and landscapes from Kentucky to Quebec and as far west as California and Oregon. Fabulous picture by the way – thanks for sharing!

Plant ID: rushes

Question:

We have a rather unusual plant (looks like bamboo?) that has grown rapidly this year. Attached is a photo. Could you please tells us if it is bamboo and should we keep it or get rid of them. I was told that they could cause many problems in an urban environment due to their very invasive root system.

Answer:
The plant you are trying to identify is a type of rush. There are many different genus out there, most of which belong to different plant families, but the cylindrical habit of the plant with those colorful bands are quite distinguishable. There is Equisetum, which is called scouring-rush, a member of the family Equisetaceae. It got its name because early American pioneers used to gather and tie them together in order to use them as scrub brushes to clean their pots and pans. Juncus is another genus, I believe a member of the Juncaceae family, and the well known variety of that genus has more of a corkscrew appearance. If I were to guess what you have in your yard I might guess it to be a striped club rush, botanically known as Schoenoplectus tabernaemontani 'Zebrinus'. However, I must admit I am not 100% certain having only seen only one image of the plant.

Either way the cultural habit of rushes is pretty much the same across the boards. They are clump forming perennials that spread predominantly by underground rhizome. They do best in full sun in a wet environment, and yes, they can spread quite rapidly once established in the landscape. Honestly, whether to keep it or to try and pull it and remove it from your garden is totally up to you. In my backyard they are welcome as a filler in some wet areas; for a client in Brooklyn I pull them every time I visit because they drive her crazy. Because it is such an aggressive grower it can become a weed, defined simply as a plant in the wrong place, even though some species are actually native to North America. If you are worried about other plants being choked out then yes, I would try and pull it and remember to remove as many of the underground stems as possible.

Understanding a New Property

Question:
I have recently moved into my new home, the previously owner had the front landscaped beautifully. In June our 7-10 feet Magnolia tree had a lot of fly and bees and moths around it. As I looked closely I noticed that Magnolia's branches are covered with white oval spot. I have treated with some insect spray twice with no effect. Any suggestions?

Answer:
Thanks for writing. The presence of flies, bees and moths in your new garden is a great sign as they are helpful and necessary pollinators. You do not want to do anything to deter or remove them as they are helping to promote the flowering of your perennials and flowering trees and shrubs. As for the magnolia, I am intrigued. I know some species of Magnolias that have white oval spots that are a natural part of the bark and how it looks and grows. Depending on the size of the spots I wonder if you are looking at lenticels, slightly raised growths on branches that help trees like magnolias and cherries with gas exchange. Next time you inspect the tree see if the spots are uniform throughout the entire tree on branches of the same size. Larger branches will have a different look to the bark as they mature and age. If you find that the oval spots are uniformly all over the tree and the tree appears to be healthy then I am sure there is nothing to worry about. As I say, it might just be the natural characteristic of young magnolia bark. If the oval spots are just on a few branches and you are certain they look different than the rest of the tree then either follow up with me again and describe them as much as you can and/or feel free to send a digital photograph if that is an option as that might help a lot.

Where to Find Perennial Hibiscus

Hibiscus moscheutos,commonly called swamp rose mallow, is a perennial hibiscus that can grow to 6-8' tall. These days growers are coming up with cultivars in a wide range of colors.

Question:
I saw a swamp rose mallow yesterday for the first time and thought it was the most beautiful flower. It reminded me of the tropics. I ran right to the computer and identified the species. Now I want to know where I can buy one. I live in Dix Hills, NY. Any ideas?

Answer:
Hibiscus moscheutos is a great plant, and yes, very tropical looking, especially for being a native species. They do best in a full sun application, especially if you want them to set a lot of flower buds for their late summer bloom. As the common name implies, they also like to have pretty “wet feet”. In the past I have seen them growing naturally in wet, swampy or boggy areas, so make sure they get plenty of irrigation and the soil has good drainage. Certainly if you have any more questions about the cultural needs of this species let me know.

In the past I have found most garden centers or nurseries I drive-by on LI carry this plant in stock. Some places you might find carry them later in the summer because it coinsides with their naturally late-summer flower, but I hope you can track down a few in the next couple weeks. Also, if you know of any place near you that specializes in native plants then they would be a perfect place to approach and ask as well. Lastly, I will forward your query to Katherine Powis here in the HSNY Library as she has some great plant source references at her disposal.

When Multi-Colored Foliage Turns Green

Question:
I have a notoriously black thumb, much to the chagrin of my Master Gardener mother, and I can't even keep aloe alive. So I asked very specifically what to do with my coleus when I purchased it. It is lush and thriving, but has lost its color!! It was a variagated yellow and brick red when I bought it, and now it's almost entirely green. The man at the farmer's market said to keep it out of direct sunlight and to water every two days. Now I'm second guessing if that means every other day...or if it needs more sun, or what. I did not repot it, as I've had terrible luck with that in my plant-past, too. Any suggestions?

Answer:
There is certainly no need to be too tough on yourself. Chances are you just need to know a little bit more about the plants you are trying to grow compared to your light situation at home. With a little more knowledge you'll be able to grow the right plant in the right place and you will see those thumbs of your change color in no time!

So let's get to the coleus. This plant is considered an annual for us so that means it will not survive the winter outside, but can be kept going in a container inside. If we were talking about the plant being outside in a garden then the grower's advice would be accurate. Coleus (botanically known as Solenostemon scutellarioides) is a sun to shade tolerant annual and can possibly burn and/or bleach out if exposed to an excess of 5-6 hours of direct sun. However, if you have it inside in a container, you want to try and give it as much direct sun as possible. That is the reason for the loss of non-green color. The plant had that great variety of color because it was getting enough sun before. In its present situation it is getting significantly less sun so it is adapting to survive in the environment. The green in plants leaves is chlorophyll, cells devoted photosynthesis, the process of turning sunlight and water into carbohydrates so the plant can grow. Given less light, the plant has been forced to produce leaves that are all green to max-out the plant's ability to photosynthesize and hang in there. To give a personal example, I have a plant called a croton here in the office. Naturally the plant is wildly multi-colored as it is a tropical plant used to warmer and sunnier climates. However, I have it here at my desk growing under fluorescent lights. The full spectrum of light the bulbs emit is enough to keep the plant going but is not the same as a direct sun situation. Therefore, I instead have a plant that is now, like yours, entirely green.

This is how croton might look when you get it at the florist.
This is how my croton looks here in my office. Note: plant is still growing and doing fine and my thumb, still pretty green!

If I were you I would try and move it to a sunnier spot. The plant will adapt to getting more sun and hopefully the interesting color patterns will return. You might, if possible, move it to a sunnier spot in stages. Move it to a brighter spot and care for it for a couple weeks. Then move it to the sunniest spot and continue to care for it there. Moving the plant in stages will help to prevent the green leaves from getting too sunburned or scorched since now they are used to less light. As another example, I move my succulents outside for the summer. At first they might get a little fried,and I might lose some of the older leaves, but they usually bounce back pretty quickly. If you lose some leaves in the process but the plant is still producing new leaves then don't fret it too much.

Otherwise, keep the soil moist this time of year and then water a little less in winter. If the coleus has put out a lot of new growth then you should definitely repot it so that it continues to get the nutrients it needs and has room for its root to grow as well. Usually you want to repot plants when you get them as growers might have them rather pot-bound in order to sell you a full looking item. You only need to repot it to a container a couple inches larger in diameter. Clay will dry out more quickly; plastic will help the soil to retain moisture for longer. A standard brand-name potting soil will be fine. If that makes you nervous give me a ring and either I can talk you through it or we can set a time to bring the plant in to HSNY and we can repot it together.

Can You Please ID This Flower?

Question:
Could you please tell me the name of the white berry-like foliage used in this arrangement?

Answer:
I believe the flower and foliage you are trying to identify is a plant called either Japanese pieris or Japanese andromeda. The botanical name is Pieris japonica.

It’s a broadleaf evergreen shrub that sets those long panicles of bell-shaped flowers in late winter to early spring. In nature they can be quite fragrant but I am not sure how long the fragrance holds up in arrangements. I did post a few pictures of one such Pieris japonica on the HSNY blog last spring when it was in bloom in Central Park. That might help to confirm further. Here is the link to that entry, (they are the last images on the post):
http://hsny.blogspot.com/2007/04/in-bloom-this-week.html

Franklinia and Wisteria Questions

Two separate questions:
1. I live in Raleigh, NC and have a Franklin tree that could use some help. It's now about 3 years old, is planted in an area that includes pines and rhodos. I've seen one that has been kept in a pot and the leaves are beautiful--not like mine.
Could you advise me re: the correct soil ph as well as what the best fertilizer would be. Also, I'll be moving next year--is there a more optimal planting situation than it's present one (it's coming with me).

2. I have a beautiful Wisteria growing along the top of a large Pergola. The problem is that suckers keep breaking through the dirt in my planting bed and are not confined to the trunk area but break out all along the root system. I simply cut them off, but there are so many--is there any way to combat this or stop it altogether without killing the plant?

Answers:
Let’s begin by talking about the Franklin tree, Franklinia alatamaha.

Franklin trees grow best in a moist soil with a fair amount of organic matter. They are also known to have a rather sparsely fibrous root system (according to Dirr’s Manual of Woody Landscape Pants). Given those two factors, I would think that even three years later you want to still be supplying the tree with a fair amount of supplemental irrigation. Do you have a soaker hose or drip irrigation system set up? I would think the tree’s root system should still be saturated two or three times a week for 2-3 hours each time. Hopefully you amended the soil with a fair amount of compost when you planted the tree. If not, I would top dress the area right around the base of the tree with an inch or two of fresh, rich compost. If you have mulched under the tree already then you might want to remove some of the mulch and replace it with, or at least mix in, the compost. Avoid mounding compost or mulch right up against the trunk of the tree. Spreading out a few feet in diameter, your tree pit only needs a couple inches of compost and/or a compost and mulch mix to provide enough insulation for the summer months while providing nutrients to the building root system. If I were you I would not fertilize your tree with anything else at this time, especially if you are going to move it again soon. In fact, I am rarely a fan of fertilizing trees as they will prefer to grow and produce stem and foliage tissue by their own schedule, not ours. Going back to the sparse root system Franklin trees can have, consider hiring some skilled landscapers who are really good at balling and burlapping trees for the transplanting effort. If you really want to save the tree it is going to be worth the extra investment. If the root ball gets really jarred or beaten up during the move you might be dealing with that stress for years. When it gets moved, I would recommend a product called PHC Tree Saver to be incorporated into the hole (amended with compost) once the tree is in place. Here is a link to PHC’s website, and hopefully you can find a retailer near you that carries it: http://www.planthealthcare.com/HT/Mycorrhizal/PHCTreeSaver

The tree can tolerate some shade but you will get the best flower and most glossy leaves if it is in a full sun application. Definitely set up supplemental irrigation in its new home for a year or two to make sure it takes to the new situation. Rely on compost and mulch to provide a steady slow release of nutrients to the root system. A few references speak to soil pH but they do not always agree with each other. A member of the camellia family, Theaceae, I would guess they would like a soil that is slightly acidic to neutral (6.0-7.0). One reference says that they can tolerate slightly alkaline soil, but I have never seen one in that kind of situation. Since wild populations of these trees have not been found in over 200 years it seems to me that there is a fair amount of guessing in this regard. The best specimens are found in slightly colder climates (Massachusetts, Pennsylvania, etc.) but obviously your tree can be grown down in the Carolinas as shown by your friend.

Then there is the wisteria:

Suckers and water sprouts are what we horticulturists call kinds of epicormic growth. The catch with pruning them back this time of year is that the plant is growing most actively and continuing to produce plant growth regulators (what people tend to call “plant hormones”) that will continue to push out new growth from dormant buds right below where you are cutting. The only trick I have learned is to prune those unwanted shoots back in the fall as the plant is beginning to go dormant. In the fall your wisteria is going to produce another plant growth regulator that will aid the plant in going dormant for the winter. By pruning at this time you will (hopefully) trick the plant to not want to produce new growth from those points. Or, if they do, the hope is that the growth is so young and vulnerable going into winter that they do not survive and eventually die-back. You will have to repeat the process for a few years as wisteria are so aggressive (invasive!?!), but hopefully you can get the situation under control.

Notes from Around Town: GreenBranches Learning Garden at Stone Avenue Library

On July 10, 2008, there was a special little ceremony to celebrate the partnership between The Horticultural Society of New York and the Rush Philanthropic Arts Foundation and the new sculptures out at the Stone Avenue branch of the Brooklyn Public Library. Originally opened in 1914, Stone Avenue, once called the Brownsville Children's Library, was the first public library in Brooklyn designed and opened specifically for children. As part of HSNY's GreenBranches program, the garden at Stone Avenue was designed by Marpillero Pollak Architects and installed by the HSNY Green Team during winter of 2006 and opened in spring of 2007. Today it is a beautiful and aesthetic contribution to the neighborhood as well as being a programmatic space and living classroom for the local community.
(PS. if you want, click on the photographs to enlarge them to full size)
When I arrived at lunch time I found a number of our friends and partners from Rush Philanthropic Arts Foundation busy working with and teaching kids of all ages.

Meredith McNeal, Director of Education at Rush, and her class of young watercolor painters had gathered and displayed their latest creations on the benches and were having an afternoon critique. Meredith was teaching the kids about everything from artistic composition to constructive criticism, and they weren't missing a beat.

Linda Pollak, above in the striped shirt, from Marpillero Pollak Architects came out to help us celebrate and see how successfully her garden design has been adopted by the local children. You might notice the beds and benches happen to be the perfect height for a small, curious soul. Yet another genius design by Marpillero Pollak. Green Branches Learning Gardens are designed with each individual community in mind and intended to provide a long-term and sustainable benefit to that neighborhood.

Also helping us celebrate were: Gabriel Pacheco, a Brooklyn artist and educator who's handy work you will see below; Paul Levy, Stone Avenue librarian and a great friend of HSNY; and Patricia Dean who runs the Brownsville Heritage House, a must-visit on the second floor of the library.

The real cause for celebration was the completion of amazing, one-of-a-kind wooden sculptures conceptualized and realized by Brooklyn teens under the supervision of Gabriel Pacheco. You see, before the winter of 2006 this exterior space behind the library had been heavily shaded by a number of Ailanthus altissima, commonly called tree of heaven. For those of you that know this tree, you know they grow like wildfire and are known to seed themselves everywhere they are not welcome, so HSNY made the decision to remove them. The result was a tremendous addition of sun that could then be utilized for growing a wide range of flowering annuals and perennials, including some very well-received tomatoes and basil. With the intention to recycle and use as much as possible in the garden, it was then decided that this would be a perfect opportunity to teach the kids a new art form, namely wood carving. Gabriel sat down with the teens and together they conceptualized how each trunk could be transformed and brought back to life. Over two months last year and one month this year the kids worked their hearts out, as did Gabriel, and created a total of five sculptures now permanently on display behind Stone Avenue.
A year later the teens posted their original drawings on the new shade structure in back and talked us through the creative process.
Gabriel and the students found many gallons of paint that could be recycled and cut up over 200 aluminum cans to add both color and and shiny metal adornments to these unique pieces of art.
Here two chess pieces were created to stand tall behind the raised beds overflowing with perennials coming into full flower.
One young woman had in mind an arrow piercing a broken heart, and thanks to the HSNY garden space and the guidance from those at Rush, she was able to make it a reality she is extremely proud of. The more we talked the more she pointed out to me how each sculpture was individual yet spoke to a common theme, the power of both mind and body. I began to see the peices in a whole new light and they became even more amazing to me.

Needless to say we here at HSNY are all extremely proud too. We couldn't be more proud of this garden that the local community can call their own, proud of this amazing partnership with our friends at Rush, and proud of the creative youth who are so uninhibited and inspirational. Bravo!

To learn more about HSNY and our various outreach programs, as well as information about becoming a member and helping to support these necessary efforts to improve the quality of life in New York through horticulture, visit our website, HSNY.org.

Interested in Floral Design?

If you do not already know, let me tell you about a great floral design studio right in the heart of the Flower District down there on 28th Street. Robb Moss and George Vallo used to teach floral design classes for The Horticultural Society at our old location on 58th Street. More recently, they have started their own school called The New York Studio of Floral Arts. Operating out of the same building shared by Empire Cut Flowers, The New York Studio of Floral Arts allows you to attend classes and learn right there in the middle of the action on 28th Street. George just emailed me to let me know about a whole new bunch of dates they just added to their website and I wanted to let you know right away. So, If you are interested in taking excellent floral design classes while staying right here in Manhattan, definitely check out nyfloralstudio.com and sign up for the class that is right for you.

Magnolia Pruning and Care

(a young Magnolia stellata up at NYBG, April, 2005, Photo:Alex Feleppa)

Question:

We planted a nursery bought 7’ Butterflies Magnolia back in mid-May and it seems to be doing well except that there are three limbs that are drooping down and touching or almost touching the ground. Is this normal? Should I prune them away?

We also bought a “Star Magnolia”. It is a shrub, but the salesman told us that we could prune the lower limbs to make it grow as a tree. I was just reading an article on your website that said to prune magnolias as little as possible. Where we planted it, we really want it as a tree. Any suggestions on when, how and/or if I should prune it?

Answer:

A butterfly magnolia is a cross between two magnolia species, Magnolia acuminata (cucumber tree) and Magnolia denudata (Yulan magnolia), and from what I gather was originally patented in the early 1990’s. I must admit that I have not seen or worked with this new hybrid myself, but hopefully I can share some helpful information just the same. In its youth a Magnolia acuminata has a distinctly pyramidal growth habit while Magnolia denudata are quite upright (Dirr, 1990). Therefore, I’m guessing a young butterfly magnolia with a few weeping branches might not be so normal. Since it is still freshly in the ground, let me talk about the cultural needs of a newly planted tree to make sure it is getting the care it needs. Understanding your plants and their needs should always be the first step

Certainly the most important thing is giving the tree enough water to establish good roots quickly before it goes dormant this winter. Forgive me if I am preaching to the choir, but I can never emphasize this enough. Your tree should be getting at least 20-25 gallons of water a week for the first few years in its new location. We have been having a good spring and summer as far as rain goes, but one can never rely on “nature’s watering schedule” when you plant something as large as a 7’ specimen. When I worked in retail I would often advise people to get a soaker hose and a battery operated timer, and set it up so that the rootball gets a good, thorough soak two or three times a week for two or three hours each time. That’s a minimum requirement in my book.

In addition to regular and supplemental watering, a proper mulching is a great help. We mulch to not only add some organics to the soil which eventually break down and help fertilize the tree, but really we do this more to regulate soil temperature. Using a nice thin layer (1”-2”, no need for more than that) of a shredded wood mulch around the base of the tree helps to prevent the soil temperature from fluctuating greatly between day and night. This little bit of insulation can be really important as you want to make sure the roots are constantly moist and protected through the growing season, especially for this year and next. Not to mention mulch rings can be great natural buffers to prevent accidental damage to the young trunk that can be caused by lawn mowers, weed-whackers, etc.

Since you only planted the tree in May it is perfectly possible that the drooping branches are a delayed reaction of some stress that the tree went through when moved and planted. Trees and woody plants operate on a schedule that can be much slower compared to other herbaceous perennials we might have in the garden, especially as they get older. I have some mature trees that I transplanted years ago and am still observing some of the effects of that stress years later. This is not to say you have to overly coddle your new tree, it is just to say that trees reactions to stress are not as immediate as we might think or expect. And trust me, I will be the first to admit that I am completely impatient in this regard.

As far as pruning, I was taught that a newly planted tree should not be pruned for the first couple years. In the interest of minimizing the stress on the tree, and thus giving it the best chance for survival, your magnolia will be healthier and happier if it is allowed to focus on root development and acclimation this season, and then deal with callusing new pruning cuts once established in the landscape a few years down the road. However, if the branches are a total eye sore and you have enough other branches and foliage that your pruning would be a minimal reduction, then I suppose you can. My hope is that by fall they will have perked up a bit and not need to be removed.

I hope that covers the butterfly magnolia for now. Obviously if you have further questions or want to share photographs of the tree, you are more than welcome.

As far as the Magnolia stellata (star magnolia), that is a very good question. I’m glad you asked because this touches on the most important thing that people often do not consider when buying a tree, namely its natural growth habit. If you see them in the landscape, or do a Google image search, you will see that star magnolias have a pretty full, rounded habit with decent foliage all the way from the ground up. This is not to say that you can’t prune the limbs up some, but I would take a pretty slow and steady approach because you will be altering the naturally intended shape of the tree. This is, of course, unnatural by definition. As with all tree pruning you want to make the minimum amounts of cuts to achieve the look you are going for. If you prune off 25% to 50% of the total stem and leaf tissue of your tree then you will be sending it to an early death. This sounds extreme and slightly ridiculous, I know, but unfortunately I have seen it done. Depending on the size of the tree and how long it has been in your landscape, I would think about a pruning agenda spread out over 3-5 or more years instead of trying to achieve a major change in one. After all, I assume you are hoping to enjoy the tree for many years to come so think about tree care on that same timeline. This fall, after the hottest and most stressful part of summer is behind us, go ahead and prune off the bottom couple branches. Doing this in the fall the tree will still be able to callus the cuts before it goes dormant for the winter. Next year, when the tree has a healthy new flush of growth on its upper limbs, and you know it’s gained a lot of new stem and leaf tissue, then take off a little bit more off the bottom.

You see where I am going with this, right? With a slow to moderate rate of growth, your star magnolia is going to be more shrub-like at first. Again, that is the natural habit of the tree and you can’t change that quickly without putting the tree under major and unnecessary stress. However, as time goes by you will chip away at it and eventually you will have the specimen you hoped for.

Dracaena Propagation Update from Seattle

So, for those of you that are regular readers of the HSNY blog, you may remember a story from February of a woman dealing with her Dracaena about to poke a hole in the cieling of her apartment out in Seattle, WA. If you need a refresher, here is a link to the original piece.


This week I received a fabulous update from Angela that really made my day. Sometimes I get nervous when I am advising people thousands of miles away, so to hear that her propagation efforts were a success I was so thrilled. Here is the update from the west coast as well as my answer to a new question that came up. Enjoy.


Hi Alex,
I just wanted to thank you again for your help earlier this year. I wrote to you in February asking about my Janet Craig. Here is an update:
At first I tried air layering, but that only lasted about a week, because the top got too heavy and snapped off where I had made the incision. I was too busy to deal with it, so I took the top and stuck it in a vase of water for about two weeks. Finally, I cut the top into two separate pieces and planted both in peat moss like you said. Now, about 6? weeks later, there are two little baby plants with great roots (see photos), and there is also new growth on the bottom plant as well.
Awesome! Now I have a Janet Craig family. Just one question, when can you transfer the plant to regular soil? They seem to like the peat moss - can I leave them in that?

Image 1005 shows the papa plant...

...and image 1010 shows where the papa broke off and where there is new growth.

Image 1013 is baby#1 and image 1014 is the baby#2. Image 1018 and 1019 are the new roots of baby#2.

To the update I replied:

All the cuttings look great and you are right, you have a good amount of roots there. So glad my advising worked - phew! To answer your question I think this would be a fine time to repot them into a mix of regular potting soil, perhaps amended with a little extra peat moss. The reason you used peat moss was to anchor them and provide water to the cuttings to get them to root without tons of extra organic matter that the cutting would not have been quite ready for. Now that you have good roots, the plants can begin to be situated in pots with increased organic matter and that will provide them with the nutrients and water retention they need going forward. If you were to keep them in just peat moss you would probably find that they would become weak over time. When my cutting here in the office established roots much like the ones you have I repotted it in regular soil and it is doing just fine now.

This Evening at HSNY

The Horticultural Society of New York presents:

WORK ARCHITECTURE COMPANY

JULY 10 - SEPTEMBER 5, 2008

Opening Reception @ HSNY: Thursday July 10th, 6 to 8 PM

This exhibition is on view at the HSNY Gallery as part of the program for WORK Architecture Company's concurrent outdoor installation PUBLIC FARM 1:'SUR LES PAVES LA FERME!' at PS1/MoMA. Our exhibition will feature architectural models, prepatory drawings, studio sculptures and photo-documentation from this project.

Photo courtesy of WORK Architecture Company

Photo courtesy Elizabeth Felicella and WORK Architecture Company

Gallery hours: Monday - Friday 11am - 6pm & by appointment

In Bloom This Week at HSNY

In our Green Screen here at HSNY we get to have a lot of fun growing a wide array of plants. Among them we have a number of epiphytic species, including these Tillandsia, or air plants as they are commonly called. They are situated in a trough of moisture retentive gravel and get watered and misted a couple times a week this time of year. After a day in the field working at a Green Branches Learning Garden in Brooklyn yesterday I came in this morning to find these showy pink blossoms emerging from the rigid green leaves. Well, technically speaking the pink portions are showy bracts and the flowers will actually be smaller and emerge from the tiny purple buds you see. But either way, a great little show.
If you are in the neighborhood come in and visit to see these spectacular plants. The blooms will not last too terribly long as the office is considerably more dry compared to the humid locales of Central America where the genus is naturally indigenous.
The HSNY Green Screen was designed by Marpillero Pollak Architects, installed by David Melrose, and is maintained by those of us here at The Horticultural Society of New York. It is a living work in progress, and along with the HSNY library and exhibitions gallery, is open to the pulbic Monday through Friday from 10am to 6pm.

Hope to see you soon.

Spittlebugs in Woodstock, NY

Question:
Hi, we planted five variegated dogwoods on our property in Ulster County last fall and after bursting to life in the Spring they now all have a white sap-like substance oozing from the leaf stems (please see attached photo) at several points.

Would you know what the problem is and how to treat it?. Over time, the leaves die and the problem moves to another part of the plant.

Answer in the form of a question:
Thanks for writing. I can’t make it out quite so easily, so let me ask you a question:
The sap-like substance, is it kind of foamy? Meaning, not very thick and viscous, but more like white foam or froth?

If so I am guessing it might spittle bugs. But let me know a little more and we will try and diagnose more concretely.

Answer to my question:
Yes it is more foamy than viscous. If you can identify we would be really grateful. The plants are at a house in Woodstock. They are the only plants affected like this.

My long-winded answer:
Thanks for the confirmation. I think it is pretty safe to say that what you have attacking your Cornus is a pest called a spittlebug. There are a number of different species of spittlebug but there is one that feeds specifically on dogwood, aptly named a dogwood spittlebug. This might also explain why they are not affecting other perennials or shrubs in the same area. Without seeing the pest myself, I must admit I am guessing, but a confident guess regardless.

Let me first give you some information about their life cycle. Inside the foamy mass of “spittle” there are spittlebug nymphs using their piercing/sucking mouthparts to feed on the delicate new growth of your shrubs. The spittle helps protect them and keep the area moist right around them so that they do not dry out. The nymphs are likely ¼” to ½” long and oval-shaped, and either yellow or yellow-green in color. (there can be some slight variation between species). If you inspect further I am guessing you will find them feeding mostly on the undersides of the new leaves where they are likely to be, again, cool and protected. Nymphs morph into adults with a similar appearance who will feed through the rest of summer and then lay white to beige eggs in rows in the leaf litter this fall.

I am glad that you have noticed them now because this is a good time to treat them. As with most pest issues, if you can find the time during the pest’s life cycle when they are in their most vulnerable form, and then attack them, you have the best chance for successful control. Even though the masses of spittle are pretty gross and overwhelming, you can rest assured that these pests are not likely to kill your Cornus shrubs. Enough damage can deform and stunt new growth, so you might have to do a little pruning late summer or early fall, but at least you don’t have to begin redesigning your garden.

As a first plan of attack I would treat your shrubs with an insecticidal soap. I should say that some believe that blasting the spittle masses with your garden hose on a strong stream is enough to disrupt, destroy and control them. However, if you are dealing with such an infestation then I am going to say let's go ahead and jump to the next step. Available at your local garden center or nursery, insecticidal soap is designed to coat and dry out and/or suffocate small garden pests that feed using their piercing/sucking mouthparts. Sold as a ready-to-use spray, coat the affected areas of your shrubs by spraying to the point of runoff. Remember that the nymphs are most likely hiding in the most protected spots, so be sure to spray the undersides of the affected leaves and stems as well. You will probably have to repeat treatment for a few weeks until you see the situation improve. Of course, read and follow the instructions on the label. Even though tedious, any physical removal of the pests and protective spittle you can do is going to be a help. If the nymphs are exposed to the hot summer sun and stressed out they should not be able to feed with the same ferocity. As a precautionary step for next year, you might choose to rake up and garbage bag the leaf litter this fall instead of leaving it or composting it. Hopefully that way any eggs that adults were able to lay will be removed before they hatch next spring.

If the combination of insecticidal soap and physical removal does not work, let me know and we can try and figure out the next serious step. I think I covered all the bases for now, but if anything is unclear, just let me know. Good luck.

A few days later, the dialog continued...
I will get the spray and saturate the plants to the point of run off this weekend and follow up with further applications. I assume "insecticidal soap" is a readily understood generic term.
One question for now, if I bag the leaves in the fall and hopefully remove any eggs, what are the odds of a new infestation in future years? Is it likely I will have to do this every year or spray early in the spring to prevent it?

And to that I replied:
Insecticidal soap should be a generic enough term and pretty easy to find at a garden center or large retailer. The most common brand name you will find is a company called Safer, so many refer to it simply as Safer Soap. Their products are excellent. I think there is also an organic one made by a company called Concern which we have used in school gardens. Either will work just fine.

There is a chance they might come back next year even though I think you have a good chance of getting the situation under control. Removing the leaf litter will be a helpful practice and then you can lay down some fresh compost or mulch in its place to protect the roots through winter. I’d hold on to the rest of the insecticidal soap as you may find a small population of them next year. But now knowing what you do, you will treat the shrubs again at the first sign of the spittle, and that should wipe out the remaining nymphs. Hopefully by two years the problem will be behind you.

Ant Infestation!

Question:
Here's a weird problem: for the first time in the three years we lived in our 6th floor apartment we have an infestation of little black ants. Worse yet, they seem to have taken over several potted plants and turned them into "ant hills" by colonizing through the bottom of the pots.
Do you have any suggestions about how to clear them out? I will appreciate any guidance you can offer, as I know the Horticultural Society has been able to help us in the past about other matters.

Answer:
Nice to hear from you. Honestly, that ant situation is a new thing to me. I must admit, though, that I do not know as much about ants as I do other garden pests. This is what I do know:

Ants themselves do not typically do damage to or kill plants. (If they are doing damage to the roots via their tunneling, that might be another story). If ants are present, it is typically because they have found a source of honeydew to feed on. Aphids and other garden pests feed on the leaf tissue and their excrement, technically called frass, is a sweet, sticky substance called honeydew. Large quantities of honeydew on leaves can lead to a dark fungal coating called sooty mold, and can also invite ants to feed.

I would recommend inspecting your plants and seeing if you see any other signs of insects. Be sure to look on the undersides of the leaves and at the nodes, the junctions where stems and leaves meet, as these are safe places for pests to hide and feed. If you find other culprits, (aphids, mealy bugs, etc.), treat your plants with an insecticidal soap, which you should be able to find in the Flower District or at a local garden center. The insecticidal soap will not deter the ants directly, but hopefully it will wipe out any food sources that might be present and they won't be so inclined to stick around. As far as a treatment for the ants themselves, I am sorry to say I do not have a quick answer right now. We have some text here in the Library so I will review that and see what we come up with. Given this day and age I'd probably do some Google searches too and see what others recommend.

Hale Damage and the Topic of Senescence

Question:
We recently had two hale storms on grand island. My hostas were ripped to shreds and I am in the process of cutting them back but was wondering if that might be harmful to next years growth. Not sure if they would be like daffodils and tulips and need the leaves to stay until they yellow. Your help will be greatly appreciated.

Answer:
Thanks for writing. Your assumption is right on target. In the world of horticulture there is a word that gets thrown around called “senescing” or “senescence”. When perennial herbaceous plants, like your hosta, begin to naturally yellow and die back in the fall we call that senescing. (Funny enough the verb “to senesce” can be difficult to find in some dictionaries, especially as it relates to horticulture and biology). And even though plants will senesce at different times of the year, the general premise holds true across the boards. Typically by that point the plant has achieved its fundamental biological goal of flowering or producing cones or producing spores in the hopes of reproducing and staying alive as a species. It has then maintained foliage to continue to photosynthesize and store nutrient and carbohydrate reserves for next year. By the time a plant yellows it has built up enough to leaf out and/or flower next spring and can thus go dormant for the rest of the off season. For this reason, most garden plants, from spring bulbs to late flowering herbaceous species, will be happiest and healthiest if allowed to keep their foliage until it naturally yellows and dies back.

As far as your dilemma I completely understand. Two years ago I was working at a public garden and a hale storm destroyed the majority of the large leaf plants in the woodland garden and we didn’t quite know what to do. I suppose what I would recommend is to leave what leaves you can. Even if the plants look a little lop-sided or sad, it will be best if they can utilize what leaf tissue is left to build up energy reserves before the fall. However, if they are really trashed then you have to do what you have to do, even though not ideal. You will sacrifice this years flower and the plants might get a slower or later start next year, but luckily hosta are some tough plants, so I can’t imagine you will actually lose any. Perhaps the plants will push out a new flush of growth this year, but I don’t want to get your hopes up in case that does not happen.

Pinus mugo in Containers?

Question:
I am a Landscape Design student @ the NYBG and we need to design a roof garden.
I would like to put PINUS mugo ( good size) in tall planters. The building is 5 stories high in Brooklyn. Do you have comments on the resistance of that species in container or other idea beside Buxus? Physocarpus? Thank you

Answer:
For that situation Pinus mugo should be fine, as long as it will get full sun, have decent drainage, and receive regular irrigation. I have certainly seen and used it in containers, and even though it can get large and wide over time the slower growth habit, compared to other pines, I find to be an attractive characteristic. The only concern I have is installing them at a "good size". If you really want to make sure that they take well I would not install very mature ones, but would go with younger specimens at first. As with other plants, especially in a challenging situation like a rooftop garden, I plant as young as I can get away with to make sure they have the best chance to acclimate quickly asnd successfully. Once you start bringing in mature pieces they can be so used to the light, temperature, and irrigation they were getting before that the new situation can throw them into some shock. Not to mention if you spend the money on mature plants and then deal with getting them to the space for them to then go into quick decline, no one will be happy, neither you or your client.

I would also recommend coming to the HSNY Library if you are still in the planning stages. A horticultural library with over 10,000 volumes open to the public I am sure we have some references that will be of assistance. The Library is open to the public from Monday to Friday, 10-6pm, and Katherine Powis, the full time librarian, is here Monday through Thursday.