Question about fire and bulbs

Mary Sue Ittner
Wed, 11 Oct 2006 17:58:42 PDT
Dear Mary,

It appears that fire does stimulate some geophytes to bloom. Although smoke 
seems to be one of the factors involved,  additional light and extra 
nutrients available are also play a role. If an area has a lot of 
vegetation  a fire removes that vegetation and a lot of things that 
couldn't grow and bloom before now have the space and light they need to 
succeed. For some plants they will continue to grow and bloom until this 
changes so they may bloom in years following the fire until the area grows 
Obviously plants in this category could do fine in a garden if you are 
giving them the light and nutrients they need.

On the other hand, a number of friends in South Africa have told me that 
there are some things that only bloom after a fire or may rarely bloom 
except if there is a fire. They come up after a fire and then are never 
seen again until the next fire. Perhaps it is the smoke that operates in 
this case. We visited some areas that had fires on our recent trip and 
there were some things in evidence (blooming) that no one knew were there. 
Rod and Rachel and Bob and I hiked near where the Saunders have property 
and where there had been a fire. There were two things we saw that they 
told us were especially fire sensitive. One was Moraea ramossissima. I 
purchased corms of this a number of years ago and when they arrived a note 
was included, "shy bloomer." I thought, oh great. I planted them out and 
have never seen them again. These plants we saw weren't in bloom quite yet, 
but they were going to bloom and there was an amazing number of very large 
plants (plants generally 50 to 120cm high). Rod and Rachel said next year 
they won't come up at all, but will wait for the next fire. There was also 
a patch of Knifophia in wondrous bloom that they also predicted would not 
bloom next year.

So when you see in books, blooming only after a fire, it may be true for 
some plants or mostly true, but there may be others that do well in 
cultivation. I've been told that some Watsonia species are fire sensitive 
and may come up and only a few may bloom most years, but after a fire 
almost all of them are in bloom. The Watsonias I grow are generally very 
reliable however. Cyrtanthus is another genus that has species listed that 
supposedly mostly bloom after fires. Rachel and Rod suggested  we could try 
pouring smoke water over our plants to see if that would bring about 
blooming in plants that normally do not come up and bloom. I asked if they 
had ever tried it and they said no. I tried smoke water in a couple of 
germination trials and although I think it was really helpful with the 
Ericas I never thought it made much difference in my bulbs. I heard someone 
suggest adding wood ash would help and have added that to pots without 
seeing any difference. And I think when I once asked before if anyone had 
found adding smoke water brought about blooming in shy bloomers no one 
reported any experiences that it had.

There are always species I am successful growing and flowering that I 
shouldn't be able to it so sometimes it might be worth trying. Can anyone 
report a fire sensitive plant that blooms reliably for them? I was 
surprised to see on that web site Brian sent us to that  Freesias were 
listed as something needing fire to sprout. That hasn't been my experience. 
I think Mary's question is a really good one and I know when I read only 
flowers after a fire I wonder if it is worth trying. Anyone out there get 
Moraea ramosissima to flower for them every year.

Mary Sue

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