Most vegetables grow easily from seed. Some vegetables such as corn, beans, peas, radishes, and most other root crops don't transplant well so are best planted directly in the garden. Start others, such as artichokes, celery, tomatoes, peppers, and eggplants, indoors or purchase them as transplants if you live in a short-summer area.
Sow onion, broccoli, lettuce, squash, and cucumber seeds indoors or directly in the garden. Follow the planting instructions on the seed packet, whether you start seeds indoors to get a jump on the growing season or plant directly in the ground later in the season when conditions allow.
Test Garden Tip: Plant seeds two to four times as deep as the thickness of the seed.
The best time to plant a particular vegetable depends on its cold tolerance and the average last frost date in your area. Cold-tolerant vegetables such as radishes, peas, and carrots can be planted up to a month before your average last frost date. Most vegetables, however, germinate better in warm soil, so it's better to wait until after the average last frost date to plant them. Some can be planted later in the season, too, so that the crop doesn't mature all at once.
Test Garden Tip: After you've harvested vegetables from an area, replant that spot with another crop to get the most production out of your garden. This technique is called succession planting.
One week before you're ready to transplant vegetable seedlings into the garden, start hardening them (acclimating them to outdoor conditions before planting them in the garden). Find an outdoor location that's protected from wind and receives morning sun. Place the seedlings in this location for a few hours the first day, then bring them indoors. Gradually extend the amount of time they're left outdoors so that by the end of the week you can leave them outdoors overnight. If the weather is not right for transplanting, you can hold seedlings in a cold frame until you're ready to plant.