The Best Time to Start Seeds

How do you know when to start seeds? To beginning gardeners, the answers can sometimes sound pretty confusing: Sow peas early, but not beans. Start tomatoes indoors but sow radishes outside. Count backward and forward ...

True, every species has a different "time to harvest" and different temperature requirements, but if you're armed with the last frost date for your area, a calendar and your seed packets, you can figure it out.

Directions on packets give you the number of weeks the seeds need to develop before they can be safely planted outdoors. The time for planting will depend on your last frost date, then whether it's a cool-season or warm-season plant — or something in between. The packet will give you hints:

• "As soon as the ground can be worked." Translation: This crop can handle frost. The phrase is usually used to describe peas and spinach.
• "Sow two weeks before last frost date when soil temperature is at least 40 degrees." Translation: Some seeds do better when they're sown directly into the ground (or container) rather than set out as transplants. This crop, probably radishes, can tolerate light frost.
• "Plant when all danger of frost has passed." Translation: The plant — typically a tomato or pepper — is very sensitive to frost. To be on the safe side, wait a couple of weeks after the last frost date for your area before transplanting outside.
  
  The perfect plant for setting out into the garden is small but sturdy (no leggy stems) and has a good root system but isn't yet pot-bound. And the perfect time to set out that transplant is when the soil and air temperatures are right for that species, such as chilly for pansies and warm for melons. Coming even close to those ideals requires a little bit of luck and, yes, counting backward.