Mary Sue Ittner
Mon, 26 Apr 2004 07:36:08 PDT
Dear Tsuh Yang,

Peter Knippels attended the IBSA conference in South Africa last year and I 
had a chance to meet him. Peter lives in the Netherlands and grows bulbs 
indoors. He found when he was looking for information about how to grow a 
large variety of bulbs indoors there were few references. So he wrote a 
book about his experiences to fill that gap. It is a thin volume (about 100 
pages), but quite remarkable as it includes so much information. The title 
is Growing Bulbs Indoors by P.J.M. Knippels. Although there are a few bulbs 
described from other areas, the focus is on bulbs from South Africa, South 
America, and Chile. Peter gives background information on many genera and 
then describes the easiest species to grow. And it tells you how deep to 
plant, when to plant, when they will bloom, etc. Peter wrote this book in 
his early thirties and it is remarkable to think he had already learned so 
much. I always find books and articles written by people who have grown 
what they are writing about so helpful. Perhaps there will some day be 
another volume focusing on some of the genera he left out.

I am amazed at some of the things that he has been able to grow indoors. In 
the back in the third appendix I see that he has classified Lachenalia in 
the "very experienced growers" category (along with Boophone, Brunsvigia, 
Bulbine, Bulbinella, winter growing Cyrtanthus, Gethyllis, winter growing 
Gladiolus, Massonia, winter growing Moraea, Nerine, winter growing 
Ornithogalum, winter growing Oxalis, and Whiteheadia.) A critical factor in 
growing Lachenalia indoors he writes is that you need to grow them in cool 
temperatures. Otherwise the plant will produce large, weak leaves without 
markings, no flowers and they will go dormant early. He also points out 
that they are susceptible to Fusarium which is one of the diseases that I 
was talking about.

Many species come from very dry areas and it can be a tricky balance in a 
container to give them enough water so the leaves don't droop, but not so 
much that they rot. He recommends watering only when the soil is dry and 
then not a lot. Graham Duncan on the other hand recommends a good soaking 
every two weeks. I found that wasn't enough for many of the ones I grow. 
Some growers plant the most susceptible in straight sand.

In addition if you live in a wet climate like mine when there can be days 
of cool humid weather and no sunshine bulbs grown outside can get other 
fungal diseases that start in the leaves and spread to the bulb. In Don 
Journet's article he noted he didn't have much problem with that in 
Australia, but I have with some species. Lachenalia zebrina I did not get 
beyond the pretty striped leaves one year when it rained a lot during 
November and December just after they had started into growth. Lachenalias 
are also susceptible to the ornithogalum mosaic virus and Don lists bulb 
mites as a problem too and said he wasn't sure whether the mites caused the 
bulbs to rot or attacked damaged bulbs.

Growing indoors you may not have some of these problems. Mark Mazer grows a 
large number very successfully in his greenhouse in Connecticut. I assume 
temperatures are cooler there than they would be in a house. But perhaps 
he'd like to comment. Peter recommends growing from 12-17º C (53.6 - 62.6 ºF.)

When I repot I toss any bulbs that look at all diseased. I have tried some 
of them from the desert areas, but as would be expected I do better with 
those that come from areas where they normally get more rain.

I hope this helps.

Mary Sue
>i have a question: what does it mean for the bulb to be diseased?

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