You don’t need to plant everything as seedlings. For those annual flowers and vegetables that you want to sow directly in the soil from seeds, follow these steps:
Determine the right time to sow the seeds in your area.
Use your seed-starting schedule, look at each seed packet for information on the best sowing time for your region, or contact the Master Gardener Program in your area to determine the right time to plant.
Prepare the soil.
Prepare your raised bed or garden soil the day before seeding. Remove large rocks, sticks, and other debris and amend the soil with a 1- to 2-inch-thick layer of compost.
Sow your seeds in patterns.
Sow your seeds in straight rows or broadcast them in wide rows. Straight rows are more orderly and easier to weed, while broadcasting seeds allows you to fit more plants in the bed. Broadcast sowing works best on raised beds. Sow at the proper depth and spacing for each seed, based on the seed packet information. Press the soil over the seeds with your hands or a hoe after sowing.
Gently water the seed bed.
You want the water to soak into the soil and not wash away the seeds. Use a soaker hose or a watering can with small holes in the head so only a gentle spray falls on the seed bed.
Weed your garden regularly.
Watch for weeds in your bed and pull them as soon as you see them. If you become familiar with what your young seedlings look like, it will be easier to figure out which seedlings are weeds to pull and which are plants to keep.
Thin your seedlings.
After the second set of leaves (called true leaves) forms, thin your seedlings to the proper spacing based on the recommendation on the seed packet. Unthinned seedlings will be overcrowded, resulting in poor root formation (for root crop vegetables like carrots) or poor flowering (for annual flowers).