Although many gardeners are used to purchasing tomato transplants from stores or growing new plants from seed, tomato plants can be grown from cuttings as well. Gardeners wishing to grow fall tomatoes can start them as cuttings from suckers that were pruned away from their spring tomato plants, according to Texas A&M University.
Cuttings should not be rooted by sticking them in the ground or in soil placed in a container. Soil contains tiny microbes such as nematodes that can attack the plants and kill them. Instead, according to NC State University, you should prepare a rooting medium that uses one part peat moss, one part compost and one part sand. Sand provides adequate drainage for the cuttings, while compost provides nutrients and peat moss creates a slightly-acidic environment that tomato plants thrive in. Fill a seedling tray or a 4-inch container with the soil.
Tomato plants root quite easily on their own, but you can provide more roots and help the plant thrive if you will dip the end of the cutting in rooting hormone before planting it. According to Texas A&M University, studies conducted with rose cuttings show that rooting hormone will increase the likelihood that your cutting will take root and will increase the number of roots that the cutting produces. Remove all leaves except for the top two and dip the lower three fourths of the plant in the hormone. Insert the plant into the soil three fourths of the way. The plant will develop new roots at the spots where leaf stems were removed.
Until they develop roots, cuttings will continue to loose moisture through their leaves with no way to replace it. According to NC State University, you can prevent a cutting from drying out by placing it in a humid environment such as a greenhouse. If you don't have a greenhouse available, you can create one by placing a plastic bag over the plant and positioning it in a sunny windowsill. The plastic bag will hold in moisture around the plant and prevent the drying. Remove the bag from the cutting once it develops roots.
When you transplant your new tomato plant into your garden soil, it may appear spindly or leggy. Tomato plants that exhibit these signs can be transplanted deeper than soil level, according to Mississippi State University. Simply remove all leaves except the top two and bury the plant up to these two leaves. The transplant will develop roots along the stems wherever the leaves emerged from the plant. The plant above the soil line will appear very healthy and strong thanks to all these roots.