One of the joys of horticulture is that there are constantly new things coming along. Now some of the active agents in smoke, following a brush fire, have been isolated, and named. This is wonderful progress, and is coming from Perth Australia, on the lower west coast . The regeneration of a burned area is dependant on some of the chemicals in smoke, because they TERMINATE seed dormancy. It makes me wonder if those chemicals are found in that "Liquid Smoke" we used to use making bbq sauce...
Here is a link, keep googling and there is lots more. This could unlock some of the mysteries of seed dormancy, and those stubborn and impossible to germinate seeds. Frank
This discovery of dormancy breaking chemicals (KARRIKINS, K1,K2,K3,K4),
Is a new class of plant growth regulators... If you had a bottle of this chemical combination, a short soak and voila----you are in business. If you have seeds you never could germinate, soak them in this and you have a new success...
I realize that this may not apply to your major successes, but think of it... A bottle of dormancy breaker! For Irises, lillys, wild collected species, and all those amateur plant breeders that have to wait up to 7 or 8 years to see results.
The importance of this work and discoveries is break through science. I have seen only a few Convolvulus species that need smoke, but posted this here for all.
Apparently I only grow easy to germinate seeds, because I've gotten plants from most of the seeds I've sowed. My biggest issue is getting plants to grow here that aren't recommended for my zone. I have a whole new attitude about all those plants I didn't think I could grow in zone 9b/10a. Only a few have not grown or bloomed here in my zone. It opened up a whole new set of possibilities of plants for my yard! :-) :-) :-)
Frank - I think it is mainly just a matter of being educated about growing plants in a specific climate range. Serious gardeners take the time to research and learn what works best. Often it is a trial and error research as well. I'm still learning and hope to do so until the day I die.