Update 2018 - Aeschynanthus Rasta - About two years ago while perusing "Beths Flower Shop" in Prattsville NY I noticed an Aeschynanthus I had never seen before. It had small leaves and flowers unlike "Pulcher", which is quite large and I thought it was a good candidate for gardening under lights. Beth allowed me to take a cutting which I dissected and propagated into about 8 cuttings which now after 2 years reside in this dense 8" hanging basket. It is now producing about a hundred buds and first flowers. It took me some time to get an identification of this species plant. It is a vigorous growing variety and does very well under lights .

About the Gesneriads:

The Gesneriads are a large group of largely tropical plants that are commonly grown as houseplants. Some of the most well known Gesneriads are the "African Violet" - Saintpaulia and the "Gloxinia" - Sinningia Speciosa. Most of the Gesneriads do well in an East window, or set back from a South window as they are native to the rain forest and only receive filtered light in their natural habitat. Most of them like a brief dry spell between watering and they should never be allowed to sit in water for a long period as they will drown.

Day Length Control:

Soil less mixes and constant feed:

The key to success with indoor plants is sterility. We start with a potting mix:

• part pearlite
• part vermiculite
• 2 part peat

depending on the the crop being planted I might add some lime source.

Okey now there is nothing of nutritive value in the pot and therefor nothing that will decompose in time but this plant is completely dependent upon you for for its nutrition. This is supplied either by constant feed program. Or a monthly feed program:

The standard of the greenhouse industry for the past 40 years has been Peter's 20-20-20 which is a complete plant food with trace elements in a highly soluble form that the industry can inject in the watering automatically. I still rely upon this and purchase in 25lb bags. A bag lasting for several years.

• Contant feed 1/4 teas/gal
• Monthly feed 1 teas/gal

It is important to water with significant amount so that it goes in the top and out the bottom each time fertilizer is applied so that old fertilizer is washed out of the pot.

A word of caution is necessary about "Constant Feed Programs". Each time you water you put the feed solution in at the top of the pot with enough excess to come out the bottom this helps to move old fertilizer salts out of the pot. Over a period of time because a lot of water is being evaporated there is a danger that fertilizer salts can build in the pot. To guard against this once ever couple of months I take my violets that are not blooming and give them a warm water shower for about 5 min. This will clean out the pot. I find that if a violet is nearing the end of its bloom cycle if you debud by removing all bloom stalks from the plant and give it this treatment they set new buds very quickly.

The potting mix has no nutritive value so the plants are depending on you to supply this. Feeding is done by what is known as a "constant feed program" or "nutriculture" this is similar to hydroponics but the plants are growing on soil. The feed I use is 1/4 level teaspoon, Peters 20-20-20, per gallon of water. I adjust this rate according to the plants response which is variable depending on season temperature, heating and other factors. With AV's it is easy to see how much nutrition they are getting. AV's should be bone dry before watering I find this period to be between 1 week and 2 weeks in my environment. In this period of time you will be able to see the effect of the last feeding because the center of the plant will reveal this. If the meristem, center of the plant, is darker than the surrounding leaves the nutrient level is high. If the central crown is lighter in color than the surrounding leaves the nutrient level is low.

African Violet Culture:

The "African Violet", Saintpaulia ionantha wendelii, has always fascinated me. In my experiments growing plants under lights it is a winner. It is tolerant of a broad range of conditions and environments and thrives on low light levels 400 ft candles is sufficient but improved results are achieved with 800 ft. candles. In general my experience has shown that having the plants close to the tubes but not touching is a good starting point. The mix I use for under lights is 1/3 pearlite course, 1/3 vermiculite, and 1/3 peat moss. More recently I have started adding quite a bit of #1 stream wash gravel which is being added for weight as the pots with the light mix above do not stay well seated in flats. Also AV's like to be under potted and the stone helps large plants in small pots to remain upright. Weight used to be a big factor as we did mail order shipping. AV's can also be grown in a east window.

I grow the Gesneriads under lights for most of the year. I run my lights 14 hrs. per day. I have experimented with a broad range of bulb types and the plain inexpensive cool white seems to work just as good if not better than plant growth lights. African Violets and the rest of the Gesneriads are easy to propagate. Just stick the cuttings in a mixture of half pearlite and half vermiculite. I cover the propagation box with glass for the first 30 days after which I feed the cuttings with fertilyzer at the rate of one quarter level teaspoon to one gallon of water.

Tissue Culture and the Gesneriads

During the late 1960's I began experimenting growing plants under lights. I had worked on the installation of 200 - 2000w Lucolox Lamps for Seagrote Florists a rose growing company in Berlin NY. The idea was that by extending the day length that roses could be made to bloom even in the short days of winter. Seagrote is one of the largest rose growers in the world with 4.3 acres under glass and this method allowed them to nearly double their yearly production.

This experience motivated me to start experimenting with various plants under lights. I found that most plants did not do well under lights as they required more light than my florescent lights could provide. In my search for new plants that would do well under lights I went to a small greenhouse operation in Colonie, NY. where the grower had thousands of African Violets in his cellar flourishing on nothing other than florescent lights. This was my introduction to the Gesneriads, African Violets and their relatives.

I had a friend who had graduated from Cornell who had been one of the first students to experiment with a new technology called tissue culture. This method allowed large numbers of plants to be propagated from very small pieces of plant material. I had discovered that the Gesneriads were very cooperative in propagation and perhaps this new method would work with them.

We experimented for several years with various kinds of lights, growing media, and species. The results were successful beyond our greatest expectation and in 1972 we opened the first commercial tissue culture operation in the US, "The Electric Farm".

We had simplified the Cornell procedure and created a low tech alternative. Since the gesneriads are so easy to propagate much of the expense and hardware used in the Cornell method was unnecessary. In fact we were denied a grant because our process was so simple.

Sterility is the key to successful tissue culture. We wiped all counters with Clorox, and sterilized all tools and containers in a pressure cooker. The plant material was dissected and sterilized in what we called a glove box. It was actually an aquarium placed on its side with an air tight cover with two rubber gloves attached to the cover by their cuffs. Small pieces of a leaf were first washed in a solution of 1 part Clorox and 4 parts boiled water. They were then rinsed is a solution of boiled water with a small amount of Benlate, a fungicide, added. This was all done inside the sterile environment of the glove box. The pieces were then placed in sterile canning jars that had a small amount of vermiculite placed in them for a growing media. The vermiculite was moistened with a solution of boiled water combined with 1/4 teas. per gallon of Peter's 20-20-20. The jars were then sealed and removed from the glove box and place under florescent light. For the Gesneriads we found 16hrs of light per day beneficial during the tissue culture process. We would place 4 or 5 pieces in each jar and in 4-6 months each piece would produce 5-20 plantlets. We would then open the jars, divide the plantlets and pot them in 2 1/4" pots.

This method allowed us to produce thousands of plants from one in less than six months!

When electricfarm was in operation 1969-1976 we maintained a list of over 500 species of Gesneriads and here I have listed some of them of note:

Potting

Many of the Gesneriads are epiphytes that like being potted small. Depth is important also. To high and it is impossible to water with enough to come out the bottom of the pot. Too deep causes excessive watering. Potting mix is equal parts peat, vermiculite, and pearlite. I use this mix for all Gesneriads.

Some common Gesneriads

About the Gesneriad Industry:

Sources for Gesneriads Update 2016.08.20

There has been a real decline in the number of Gesneriad growers in past years. I recently have renewed my interest in this old activity of mine. I have explored old friends, acquaintances, and businesses associates to find out the current state of what, at one time, was a major industry in the US. A lot of this product is now grown in Canada due to cheaper fuel prices. Also many of the most talented growers have died.

Albert Buell

http://forums.gardenweb.com/discussions/1911630/buells-greenhouses-in-connecticut

Was a major wholesale supplier of Gesneriads primarily African Violets to the “Kresge” chain and Gloxinias (Sinningia Speciousa ) to the florist trade. It was an industrial operation under glass with Gloxinias needing more than a square foot of space. The plants were loaded with buds but not a single flower showed on the benches as they are shipped prior to bloom. Buell operated his large complex of greenhouses by heating with waste oil which brought upon him legal problems and he was forced to curtail his production but continued, but was limited, until his death sometime about 1990. I recently wanted to purchase some genetic stock for Gloxinias (Sinningia speciosa “Florist Gloxinia” ) and was amazed to find these hybrids no longer in the trade and no longer available anywhere. These hybrids many of which were developed by Albert Buell I fear are now lost. I recollect an “Emperor” series that were spectacular.

Lyndon Lyon

http://www.lyndonlyon.com/

Was the foremost hybridizer of African Violets and Columneas and many of the species in the trade today were developed by him. I made trips to his greenhouses weekly for a period of several years 1973,74. His glass houses, all shaded with some rust colored compound, housed probably 100,000 plants with beautiful hanging baskets filling the over bench areas. He was fountain of information that he was willing to give away freely. Much of the knowledge I have today about the Gesneriads came from him. Lyndon died in 1999 at the age of 94. Prior to his death he sold the business to his son in law Paul Sarone who continues operating the business to this day. It is now to my mind the foremost Gesneriad supplier in the US today. So often I go to a greenhouse and see Lyndon's Columnea “Early Bird” one of the most popular columneas grown today. Lyndon told me it was a cross of C. hirta x C. stavenger.

Logee Greenhouses

http://www.logees.com/history

I was never at their facilities in Danielson Conn. But made acquaintance with them at the Coply Plaza Plant show in 1975. They had an interesting variety of Gesneriads for sale and I always intended to make the trip there but never did. They still have a Web: Site I note and have diversified their growing to a large variety of plants.

Mike Kartuz

http://www.kartuz.com/

I can remember circa 1973 a trip to Mikes Arlington Location where he had virtually thousands of varieties of plants. It is the most memorable recollection that I have ever seen. A virtual Alice in Wonderland hundreds of varieties of Columneas in full bloom, Episcia with loads of red flowers, Sinningias I have never seen before, it was impressive. He had a species catalog at that time with over 1000 gesneriads listed. He also was experimenting with genetic manipulation with Colchecine. I bought plants on numerous occasions there. Recently I perused his web site: what a disappointment. No named varieties. Things like Streptocarpus 3 – “Our Choice” are of no value to me. I order plants by name.

The Violet Barn

https://www.violetbarn.com/

Is a source for many named varieties of Gesneriads. They have a Web: site and I have place several orders with them for Streptocarpus. I note they list Columnea “Mary Ann” which is a Mike Kartuz hybrid I have lost also they have nematanthus tropicana a Bill Saylor Hybrid.