I have more experience of Mediterranean and continental winter growing bulbs, than with South Africans which (I find) don't always conform to the same rules. With these northern hemisphere plants it almost always leads to problems, either bacterial or fungal, if they are kept wet when temperatures get high enough that in nature they would be dry and dormant. --Heat will increase the growth rate of the problems much more than the growth rate of the plant. For both corms and bulbs which may suffer from heat while still in growth, or which produce too many small corms or bulbs, I usually plant them very deep in the pot and insulate them by filling the top third of the pot with pure gravel. The pots are plunged. If I found myself in a dessert, either hot and dry or frozen, I would probably seek shelter under rocks too... I used to keep crocuses in the frame out-side my green house on the south (hot and sunny) side, where the pots got dried out much earlier in the Summer. I get much better results with most of them, both in respect of growth and of fewer diseases, by keeping them in the cooler north facing frame. Occasionally I will take a pot of crocus into the greenhouse to protect the flowers. The corms always dwindle there unless I make a lot of effort to keep the plant in growth for a prolonged season. Then they mostly, (not all species), seem to relish the hot dry conditions on the bench for two or three months, - even such cool growers as Crocus civijicii. If any one tries to replicate this, please remember that my climate rarely has the heat which would be normal in parts of California! Peter (UK)