I would like to start seeds under lights. When is the best time to start flower seeds? The seed packet always says to sow a number of weeks before the last frost. When is the last frost?
“In this area we use May 15 as a benchmark for the last frost date, but it can be earlier or later,” says Chuck Prosek, grower at Prosek’s Greenhouse, Winfield.
If your seed packet gives you the number of days to germination, add that to the number of weeks for growth, and then count the number of weeks back from May 15. Tomatoes sown indoors generally need 6-8 weeks of growth before being set out.
Many seed packets do not include germination time. A good guess is to allow 1-2 weeks for the seeds to germinate, but if you use bottom heat, your seeds will germinate earlier and grow faster. Most seeds need warm soil of 65 to 70 degrees to germinate and grow.
When you sow seeds directly into the soil, till the upper inch of soil to loosen it for direct seed to soil contact. The outside soil temperature must be above 50 degrees for cool growing plants, and at least 65 degrees for warm season annuals, according to Prosek.
For future reference, keep a record of indoor sowing dates, germination dates, length of indoor growing period, and transplanting dates.
What is Chicagoland Gardening’s reprint policy?
Is there an overall rule about when to pinch back my leggy plants?
Would it help to apply a starter fertilizer on a poor green lawn in December? Will it give it a head start for spring? It hasn’t been reseeded.