Q. over three weeks ago I planted several vegetable seeds: Onion, carrot, radish, pumpkin, cucumber, squash, sunflower, corn and green beans. I planted them all according to the instructions, (I think). The only thing that has sprouted great are the radishes. The sunflowers have few sprouts they look really weak. Do you have any advice on how long I should wait to replant or what I can do differently?
A. On warm days in early spring, we are often enticed to plant things that require warm temperatures to grow. Then we are sorely disappointed when cold temperatures return and the seeds rot in the cold ground or die trying to grow in the too-cold environment.
Your onion, carrot, and radish seeds may be able to live in early spring temperatures, but onion and carrot will be slow to germinate and grow, so don’t give up on them just yet.
As for all the others you mentioned, they must have warm soil conditions to germinate and grow. and any frost would kill them if they did come up. Just wait until after all danger of frost is past before planting.
The Garden Planting Details Schedule (Apendix B – Page 262) in The Mittleider Gardening Course book provides very good instructions on when to plant everything in your garden. That single schedule covers 14 different subjects, and is worth more than the price of the book, in my opinion. www.growfood.com/shop.
Alternatively, you can plant them in a greenhouse or under grow-lights 3 or 4 weeks earlier than you would plant them outside. Remember to give them maximum light immediately upon emergence, and plant in 6-paks or pots to minimize transplanting shock, because everything you named does poorly as a bare-root transplant.