Plant sunflower seedlings outdoors when the weather is warm.
image by cohdra: morguefile.com
Giving sunflowers a head start by sowing the seeds indoors several weeks before the last frost date will give you a display of flowers earlier in the growing season. Sunflower seedlings are fragile, so take special care when transplanting them. You can make the process easier by starting the seedlings in peat pots. When it is time to transplant the sunflowers, simply plant the pots and they will decompose in the soil.
Wait to transplant the seedlings until the threat of frost has passed. Sunflower seedlings are very sensitive to cold.
Work the soil with a spade, adding at least 1 inch of compost to improve the soil quality and drainage. Work the compost into the soil completely.
Dig small holes just large enough to fit the peat pots. Loosen the soil at the bottom of the holes to make it easy for the sunflower roots to establish themselves. Space the holes at least 12 inches apart to give the plants sufficient growing room.
Place each pot into the prepared holes and refill the holes with soil. Add soil to the tops of the pots so they are completely under the soil.
Water the newly transplanted sunflower plants generously.
Stake each seedling with one or two craft sticks if they need support. Gently tie the seedlings to the sticks with twine.
Collect some human or animal hair and place it on the soil surrounding the seedlings to repel rabbits and deer, which like to feast on the new plants.