Tuesday, July 31, 2007

Another Plant ID: Curcuma alismatifolia

Would you be able to help in identifying the flower in the attached picture?
The flower in the picture that you sent to me looks very much like a tropical ginger. Botanically the plant is known as Curcuma alismatifolia, or commonly known as a Siam tulip. I refer to this as a tropical because it would not survive the cold winters here in New York. It is cold hardy in Zones 8-11 which means it might survive the winter in South Carolina, Georgia, or further south into Central America. In full sun Curcuma alismatifolia can grow to 2’ tall and flowers this time of year. It may be a certain cultivar, but I am not able to say which one based on the photograph. Usually you can find this plant for sale in pink, white, or magenta. If you took this picture in the northeast I would believe that someone grew it to be more of an annual. It provides great height and color in a summer garden, not to mention very popular as a cut flower, but would then have to be repurchased and replanted next spring.

Friday, July 20, 2007

Red Hook Goes Green

If you are not already aware, I want to tell you about some great green steps being made down in Red Hook, Brooklyn. Every Thursday and every Saturday from now until mid-November there is a farmers market in Red Hook put on by the folks at Added Value. Added Value is an organization that runs a 2.75 acre urban farm down in Red Hook, powered by devoted staff, volunteers, and the youth of the community. They grow an unbelievable crop of fruits and veggies that are sold at these markets and to local restaurants.

On Thursdays the market is held in front of the Red Hook Senior Center, at 6 Wolcott Street, from 10am to 2pm. (On Saturdays the market is held at the farm on Columbia and Beard Street). While you are there you can also see the new garden being installed for the seniors and local community by The Horticultural Society of New York.
The raised beds planted with tomatoes and peppers this spring are literally overflowing with foliage and bushels of produce gathered and eaten by the folks at the Senior Center.
We also use the gardens to educate the young of the community. Here these young men and women were spreading compost from the Added Value community farm and checking on the status of the crop.
In the afternoon John Cannizzo, HSNY staff member and leader of the GreenTeam, showed up to help teach some young interns the finer details urban gardening. In addition to planting and plant care, John also incorporates into every garden his knowledge of masonry and woodworking skills. Here they were working on mixing cement and laying the footings for a number of new benches and seating to be installed in the garden.

As you enter the garden at the Senior Center you are welcomed by a large Buddleja, or butterfly bush. Loving full sun, this woody shrub becomes covered with these gorgeous panicles of blossoms from mid to late summer that are roughly 4-6 inches in length. Over many years the shrub can get leggy and need pruning, but the flower always seems to be a hit with humans and butterflies alike.
While you are in Red Hook, you also have to make sure that you visit our GreenBranches Learning Garden at the Red Hook Public Library right across the street from the Senior Center. Designed and installed by HSNY a number of years ago, this garden is one of many throughout Brooklyn, Bronx, Manhattan, and Queens, where we lead demonstrations and workshops on different horticultural topics.
For more images and information on our GreenBranches Learning Gardens, including great before and after shots, check out our website: http://www.hsny.org/html/GreenBranches.htm

Peonies, Crocus, and Corylus: A work in progress

(image of an unknown peony cultivar (Paeonia sp.) I took at Tower Hill Botanic Garden, 2006)

I have recently received a number of excellent questions. I am calling this a "work in progress" because I am still researching and trying to find answers, but I wanted to share with you what I have found to date.

1 - I have 2 peonies - one of which I divided from the original. In the spring they show lots of buds with ants crawling happily all over them but only 4 or 5 of the buds actually flower. They're about 7 years old, in full sun, I fertilize them w/ bone meal in spring & fall, I prune them back to about 5 inches each autumn. What am I doing wrong?
2 - I started with about half a dozen bulbs for autumn flowering crocus (sativus). The bulbs proliferate - I have dozens now - & they put up plenty of foliage but only 2 or 3 bloom.
3 - I have a new Harry Lauder Walking Stick that I planted in April. It's growing much faster than I anticipated - from a foot, it's more than doubled in size. Is it o.k. to prune it &, if so, when is the best time to do it?


Regarding the peonies (Paeonia spp.) not blooming:
There is an old wives tale that peonies do not bloom for seven years if you transplant them. It is true that the roots hate to be disturbed, but as long as the crown buds were planted 2-3 inches below the soil level they should bloom the following year. This fall when you do cleanup perhaps you will want to excavate a little and see where the new buds are situated to make sure they are not too high or too deep. If the buds set and then we are hit with a late cold spell some of the buds can get blasted and never flower, but if this is happening year after year it seems safe to rule that out as a possible cause. Your cleanup practices seem appropriate; when I see them begin to die back I cut them flush to the ground and rake the area clean. Even though bone meal is recommended, I wonder if applying it in the fall and spring is a bit much. Because it is slow release, I would apply in the fall, but in the spring maybe you can just stick to just using compost. Peonies tolerate a wide pH range in the soil (6.0 – 7.0) and I have even seen them happy in slightly more acidic soil, so I wonder if the bone meal has slowly made the soil too alkaline (a pH of greater than 7). Have you ever had your soil tested? You can see why I want to research this question more.

Regarding the non-flowering Crocus sativus:
Fall-blooming Crocus love full, baking sun so if shade has slowly crept in the area that might help to explain the lack of flower. Taylor’s Guides state that Crocus sativus can lack flower if the summer is too cool and wet. I had thought Crocus preferred an evenly moist summer, but perhaps this species prefers a dryer summer. Of course, well-drained soil is a must, and added compost never hurts. You have mentioned that the bulbs are doing well, but have you divided them? For this species of Crocus, you want to lift and divide the corms every 3-4 years as the foliage begins to fade and die back naturally. Plant the divided corms about 3-4” deep, safely below the frost line, but do not plant them as deep as the 6” some may recommend.

Regarding the Harry Lauders Walkingstick (Corylus avellana ‘Contorta’):
I would take all the new growth as a good sign that the tree is establishing plenty of new roots as well. As you may have experienced when planting, these small trees have a very large root system given the relative size of the tree itself. I used to study under an arborist I admire greatly and he never recommended pruning newly planted trees until two or three years in their new location. The fundamental thinking is that pruning causes the tree to work harder to callus those cuts, and while getting established you want to stress the tree as little as possible. That being said, if you feel you need to prune it at this time, I recommend pruning this tree in late winter or early spring. Prune only what you have to maintain shape or remove dead, diseased, or damaged wood. Remember that your tree uses the majority of its stored energy for the process of leafing out in the spring, so again we want there to be as little added stress as possible. In the long run you should know that Corylus avellana ‘Contorta’ will reach 10’ or more in height and width at maturity. Over time the tree’s new growth will slow down, but you can expect it to grow at a moderate rate for the next few years.

Wednesday, July 18, 2007

Blossom End Rot Affecting My Tomatoes

(image from the Ohio State University Extension website)

I have been growing a small crop of tomatoes for the last number of years, and every year I have had great success and fruit production. I grow my tomatoes in the same spot every year and I know it is good to rotate them, but unfortunately my small garden does not allow me that freedom. This year I noticed a new problem and I am not sure what to do about it. As the tomatoes begin to turn red the bottom of the fruit begins to turn black and soft. I have done some research and I think the problem is called Blossom End Rot. Can you help me confirm the problem and how best to fix it?

I am really glad you called with this question because the exact same happened to me in a small garden I planted last year. The tomatoes would develop these decaying spots that were brown or black, usually at the base, or “blossom end”, of the fruit. Even though Blossom End Rot sounds like a disease, it is actually more of a cultural condition taking place between the plant and the soil it is grown in.

Sure enough, your condition is Blossom End Rot, and the reason for it is a lack of calcium in the soil. Calcium is important in plants because it facilitates water uptake and strong cell development and division. Calcium deficiencies in your tomato plants can be because it is simply lacking in the soil, but your watering schedule can have an affect as well. Tomatoes require their roots to be evenly moist through the growing season and when very wet soil is followed by very dry conditions the calcium distribution to the plant can be compromised. This year especially our rainstorms have dropped so much water in such a short time, followed by long dry spells in between, and our plants have suffered from the irregular watering. Therefore, make sure your tomatoes are well watered during the dry spells. In addition, do not be afraid to mulch your plants because that helps regulate soil temperature and moisture levels throughout the growing season.

To fix this problem I have yet to discover a “quick solution”. What I can tell you is that there are a number of long term amendments you can make to your soil so that your tomatoes next year come back with the same fervor and success you are used to. If you do not add it already, compost should be on the top of your list. Not only does compost increase water permeability and drainage, add organics and micronutrients to the soil, and improve soil structure, but it also helps regulate soil pH. Secondly, you need to add calcium back into the soil. Ground limestone can be applied once in the fall and it will slowly release calcium into the soil to help you prepare for next year’s planting. Even though they may sound like applicable products for the task, a few reference books I used here in the library said to stay away from quick lime and hydrated lime. If you cannot find limestone, then adding Gypsum to the soil will also help increase the calcium levels in the soil. If you are determined to take a much more “au natural” approach, I can tell you what we used to do in my mothers garden growing up on Long Island. Because the soil is naturally so acidic, we would get oyster and clam shells from the local seafood shop, pulverize them, and add the dust to the soil along with compost in the fall. As I say, I am sorry none of these are such quick fixes, but at least now you have a little more knowledge of soil science and know how to prepare your soil for your tomato crop next year.

Tuesday, July 17, 2007

Can I Bring in Leaf Samples to ID?

A gentleman recently called and described two different large foliage houseplants he had bought at a retail store here in Manhattan. He bought the plants for his terrace but was not sure what they were or how best to care for them. After a brief discussion I recommended that he come into our offices here on 37th Street with leaf samples so that I could better identify his purchases. And so he did.

The first leaf I could identify right away because it was a plant I have seen plenty. In fact, we have one growing here in our offices.
Ficus lyrata is commonly called a fiddle leaf fig. The glossy dark green leaves have a unique shape and can grow to be 12 inches long. In its native habitats of tropical India and Malaysia this plant can grow to become a 40’ tree. Kept in a container, however, we can restrict the growth and can usually contain them to somewhere under 10’. Regarding care, this plants requirements are much like that of other Ficus. Ficus lyrata prefers bright sun and can tolerate some direct sun. For now it can live out on a terrace, but this plant must be brought inside in the winters because it can only tolerate cold temperatures down into the 50’s. Like with other Ficus, you want to make sure not to over-water. Allow the top inch of soil to dry out between waterings. Mist and sponge clean the foliage when you see dust collect. Lastly, if you choose to, you can apply a weak fertilizer during the growing season (spring and summer), but cut back in the winter as the plant goes into more of a resting period.

The other leaf was not nearly as easy to identify. With it’s large round shape, glossy finish, and pronounced venation, I thought perhaps this too is a kind of Ficus.

However, a coworker was quickly able to correct me and inform me that it was a kind of aralia, a plant she had become quite familiar with growing up in Hawaii. Sure enough it turned out that the other “mystery plant” was in fact a cultivar of a shield aralia. Botanically named Polyscias scuttelaria ‘Fabian’, the Fabian shield aralia is a member of the Araliaceae family. Native to tropical regions of Africa, Asia, and the Pacific, this shrub is grown more for it’s foliage than the clusters of small flowers that are followed by small dark fruit. This plant loves humidity so do not hesitate to mist it regularly during warm weather. Place the plant in bright light but avoid lots of direct sun. Plant it in well-draining soil. Water moderately this time of year and cut back in the winter. Normal room temperature is fine, but do not leave the plant outside if it is below 70 degrees. When you move the plant inside for the winter, consider placing the pot on a saucer full of pebbles so that excess water can evaporate and provide humidity during the dry winter months. You can expect this plant to grow to 6 feet tall.

Can You Help ID This Plant?

Six months ago I purchased a small plant because of its attractive leaves. It was not marked with a name tag. Now the plant has become a small tree. I have not been able to identify the plant and hope you could assist. I keep it in the office for fear it may be poisonous to my cat at home. As best I can describe it the plant has the following characteristics:
-The main Stem is bronze-green in color and tree like with a main stem that is perhaps an inch wide.
-Branches form on opposite sides of the main stem and are slight unaligned from one another.
-The leaves are lanced shaped leaves - lighter green when newly formed with a reddish undertone when immature; but at the base the older leaves are darker green.
-Its flowers are from a single stem but are in clusters of 7 to 10 flowers (each flower is small pink-white color with 5 petals and star shaped )
-The fruit or berry is hanging from a single stem and is black or dark purple color but is shaped like a button instead of a berry

Well, after some research, I believe that Katherine and I were able to identify your mystery plant to genus. That is to say, we have not yet identified exactly what the plant is, but we were able to come up with the broader name and family of the plant.

To the best of our knowledge, the plant you have is a kind of Ardisia. Ardisia is in the plant family Myrsinaceae. In the genus Ardisia there are about 250 species of different tropical trees and shrubs. They are native to warmer parts of Asia, but have been introduced to Hawaii and more tropical parts of the Americas. Our guess is that it was grown down in Florida and shipped up here for sale like so many tropical foliage plants are these days. Generally Ardisia have that five-pointed flower and then set clusters of fruit. The more common kinds of Ardisia have red fruit, but I found some (Ardisia escallonoides, Ardisia solanacea, etc.) that have black fruit that look similar to what you have. Regardless of what the species is, your plant will want to grow into large woody shrub. It would not survive the winters outside, so it does need to stay indoors over winter to survive. Some only grow to 2’, but others can grow to 5’ or larger. As you have been, you want to keep the plant in bright light and keep the soil moist during the active growing season (spring, summer, and early fall). In winter you can cut down on the water because as the days get shorter the plant goes into more of a resting period. As far as your pets, I have not found any mention of Ardisia being poisonous. In fact one account said that the berries were edible, but I would not recommend trying them.

Since this plant has grown extremely fast; how can I best keep it manageable?
Can I prune the lower leaves?
Since I cannot be certain of the fruits; would removing the berries as they form disrupt the plant's natural growing cycle?

I forgot to mention in my last email that there is a kind of Ardisia that is considered a popular houseplant. It is called Ardisia crenata, or commonly known as coral berry. Originally I would have thought that you had a coral berry, but that plant is known to have bright red fruit and I know yours has black fruit. If the fruit is red before maturing to black, then perhaps you have a coral berry after all. If that is the case, (and that is a pretty big “if”), then you might be happy to know that a potted coral berry usually only gets to 3 feet or a little larger. Either way, yes, you can prune it as you wish. Pruning the lower limbs should be fine, but remember that pruning promotes new growth, so the shrub will continue to grow tall. Eventually if the plant gets pot-bound then it will naturally begin to not grow as quickly. But for now, as long as the roots keep growing and spreading so will the foliage. As far as the fruit, I do not see how taking off the fruit would affect the plant at all. In some cases, removing plants flowers before they get the chance to develop can encourage the plant to grow more stems and leaves and try again to produce a flower because their whole mission as a plant is to produce that flower and have that flower be pollinated. Once that has happened, and the flower has matured to a fruit, I do not see how removing them would encourage the plant in one way or another.

Monday, July 16, 2007

On Exhibit at HSNY

Tree Pants
New photographs and sculpture by contemporary artist Peter Coffin
Curated by Jodie Vicenta Jacobson
The Horticultural Society of New York
148 West 37th Street - 13th Floor
New York, NY 10018
On exhibit from July 11 - September 7, 2007
Gallery Hours: 10-6, M-F (or by appointment)
For more information, including press release and images, please visit our website:

(Image: Courtesy of the artist, The Wanas Foundation, Sweden, and Andrew Kreps Gallery, New York)

Friday, July 6, 2007

Houseplant Mushrooms?

Can you do me the kindness of identifying the attached mushroom? I'm not planning on eating them anyway, but I was curious to find out what they are, in the hopes that might give a clue as to how they arrived in my apartment. I live on the 24th floor of a high-rise in Manhattan, so the spores were probably either carried in by a fly, or they've been dormant in the dirt for a very long time. They appeared suddenly in a 30-year-old Thanksgiving cactus that I only water once every two weeks, so I'm really amazed that the conditions encouraged them.

I must admit that I am not as much of a mycologist (one who specializes in fungi, etc.) as a horticulturist but just the same I think I was able to identify your new findings. Believe it or not there is a type of mushroom that is commonly found growing among houseplants. It used to be called Lepiota lutea, but the scientific name has been changed to Leucocoprinus birnbaumii. Either way this fungus is commonly called the yellow houseplant mushroom. The spores were most likely in the soil, or perhaps in new soil if you transplanted your Thanksgiving cactus (Schlumbergera truncata) any time recently. I am not sure how toxic or not these fungi are, but I think it is safe to say that they are not edible. If you choose to remove them you can simply pull them out with your hands without any risk of skin rash or irritation.

If you do a Google search for “Leucocoprinus birnbaumii” you should be able to find some interesting and credible resources online. I found one page from the University of Wisconsin that was very informative. I often mention to those who are searching for plant information that knowing and using the scientific name (of plants, bugs, fungus, etc.) when doing internet searches tends to lead you to more credible sources of information. Obviously in your case the same holds true.