It's better to wait until the weather is warmer to put any of the warm weather veggies outside. It's too early to put tomatoes and cucumbers outside in zone 3. You can plant peas, spinach, kale etc. in the garden now. They don't mind a few cold nights and days. For aphid control check out our pests page at almanac.com/topics/gardening/pests-and-problems. Don't fertilize young seedlings too much. Wait until they are transplanted outdoors.
It's better to wait until the weather is warmer to put any of the warm weather veggies outside. It's too early to put tomatoes and cucumbers outside in zone 3. You can plant peas, spinach, kale etc. in the garden now. They don't mind a few cold nights and days. For aphid control check out our pests page at almanac.com/topics/gardening/pests-and-problems. Don't fertilize young seedlings too much. Wait until they are transplanted outdoors.