Heirloom tomatoes were the only variety grown before the 1940's when hybridization of tomato plants become commonplace. Found in a wide assortment of colors and sizes, Heirloom tomatoes are not as pretty looking as the perfect-looking tomatoes found in most grocery stores, but they have a more robust flavor and are chock full of vitamins and minerals. Starting your own Heirloom tomatoes at home from seeds is relatively simple and will allow you to enjoy fresh tomatoes all summer long.
Start Heirloom tomato seeds indoors about six to eight weeks before the estimated date of the last frost in your area. Although seeds can be sown directly outdoors after the last frost, you may have decreased fruit production compared to starting them indoors.
Fill a seed tray with about one and half to two-inches of seed starting mix. Use a seed starting mix that has peat moss added which will help retain moisture. Water down the seed mix so it is damp.
Scatter Heirloom tomato seeds evenly over the seed mix in the tray. Cover with approximately 1/4-inch of seed starting mix and gently firm over. Cover the tray loosely with plastic wrap helping to retain moisture. Set the tray in a dark room or basement. Check the moistness of the soil every two to three days and mist with a water bottle as needed. Seedlings will sprout in 10 to 14 days.
Move the tray to a sunny windowsill or place under fluorescent lights once the seedlings sprout. If setting on a windowsill, rotate the tray every day to keep the seedlings from bending towards the light.
Harden off the seedlings once they form a second set of leaves by planting in individual containers. The seedlings need to be hardened off before planting directly outside in a garden or they may die. To harden off, place the containers of newly planted seedlings outdoors in a shady spot for the first three days then return the containers indoors at night. Continue placing the containers outdoors for another week this time placing them in a partly sunny location and returning back indoors for the night. Once the seedlings have been hardened they are ready to be planted in a garden area.