I have been growing "Russian
I have been growing "Russian Giant" sunflowers, and in order to make them very big, the packet said it should be propagated indoors in "early spring". Slight problem - a month and a half later they are nearly 2 foot tall and growing at about an inch per day. I can't keep them indoors much longer, and our greenhouse is only 6ft x 6ft and that will need to contain other plants as well. Apparently they should be planted out after all risk of frost has past - but here that's nearly 2 months from now. At what size can I plant them out safely - even if there will be a frost - and what can I do to protect them from frosts?