In early summer when your tomatoes are young, healthy, and growing like crazy, remember that the party may not last forever. You might need replacements for tomatoes lost to weather or disease, or maybe you simply want more plants of a favourite variety. You can have all this and more by rooting tomato stem cuttings, which reach transplanting size in only two weeks, compared to two months for seedlings. And of course they are free!
Propagating tomatoes by rooting stem cuttings is easy because the plants are such willing participants. Their tendency to form adventitious roots along the stem has made tomatoes famous among botanists, for two reasons. Under good conditions, these adventitious or stem roots expand the plant’s rooting capacity, and when floods occur, they help the plants breathe. When tomato cuttings are set to root in water or soil, latent specialised cells come to life, and roots appear within a few days.
![Adventitious roots on a tomato stem]()
Adventitious roots growing from a tomato stem
Taking Tomato Cuttings
Every gardener has an opinion on tomato pruning and how far we should go. I’m a light nipper. I take out the leaves and sideshoots (suckers) close to the ground to improve air circulation and thus reduce disease, and let most of the other sideshoots go so there are enough leaves to shade the fruits from sunscald. After tomato plants grow to about 24 inches (60 cm) tall, they produce a steady supply of stems for rooting.
Propagate tomato cuttings only from indeterminate (cordon) varieties. While cuttings taken from determinate varieties will root, they will not produce as well as their parent plants. Also look for stems that show no signs of disease or insect problems, and only vegetative growth – no flowers or fruits. If a cutting surprises you with a cluster of buds, pinch them off. Those tissues were developed before you took the cutting, and the new plant needs your help to recalibrate its growth back to vegetative mode.
![Trimming tomato cuttings]()
Trim off excess leaves to reduce moisture stress when rooting tomato cuttings
Use clean, sharp secateurs or scissors to trim cuttings to one to two nodes (where leaves join the stem), and clip off all but the top three leaves. You can also trim back long leaflets. One study showed no difference in the performance of cuttings with two nodes over one, probably because the new roots grow directly from the stems. Avoid touching the stems as you trim so you don’t accidentally bruise them. Immediately place trimmed stems in room temperature water.
Tomato cuttings root fast in plain water when kept in a warm, bright place. Use small, wide-mouth containers such as spice bottles. Rooting tomato cuttings in individual bottles prevents tangled roots. Provide enough water to keep the bottom two-thirds of the stem submerged.
![Rooting tomato cuttings]()
Label containers when rooting cuttings from different tomato varieties
After a couple of weeks, when numerous white roots are visible, sprinkle a spoonful of potting soil into the water every day for three days. Tiny roots will latch onto the floating particles and start branching the way roots do when they come into contact with soil, paving the way to an easy transition from water to soil.
Better yet, root the trimmed cuttings directly in soil. There is no need for rooting powder because tomatoes are so strongly inclined to root. Use a pencil or chopstick to make a hole in moist potting soil, poke in the cutting, and firm the soil around it with your fingers. Place in a warm, shady spot and keep moist until the cuttings show new growth, at which time you can move the plants to larger containers, or to the garden.
![Tomato plant]()
Rooted tomato cuttings grow fast once planted
Planting Tomato Cuttings
Tomatoes that are grown from seed send down a vertical taproot, which is not present in tomatoes propagated from stem cuttings. Instead, roots spiral out from the main stem, so the plants may be slightly shallow-rooted compared to seedlings. Keep this in mind when preparing broad planting holes amended with a balanced organic fertilizer. Plan ahead to use mulch and drip irrigation to conserve and replenish soil moisture.
Allow the rooted cuttings a few days outdoors to get accustomed to sun, and then use shade covers after planting to reduce transplanting trauma. Warm soil temperatures will help the plants establish quickly, and you will have vigorous new plants for summer’s second half.
