After the last frosts. My climate is like California, last frosts are March 15th, i plant end of April, beg. June.
I shall probably sow seeds mid March. I am frost free and could start earlier, but that will do me quite well enough.
Well, if they're baby sprouts and it's freezing cold out, yes like for any other plant or living thing. I wait about a month after last frosts and it's all good. The plant will flower at a certain date (beg. August) regardless of its size. If you start them very early, you'll have bigger plants (longer vegetative period). 3 months veg. is good enough (May-June-July).
what do you think of 6 months veg.... fimmed and lst'd of course, under the florida sun... damn this will be fun
Growing in the forest, guerilla, I don't want to water for a long veg. period and have to hide monsters. My window isn't bad either here on the Mediterranean: March to end November.
I say as a general rule of thumb, March 21. In Canada, the seedlings would freeze to death. But this is South Cali. March 21st.