Tomato cuttings root easily in plain water, typically developing a strong root system in about a week. Tomatoes are one of the simplest plants to propagate from cuttings because they naturally produce high levels of the hormones that trigger root growth. A 6- to 7-inch cutting placed in a jar of water on a sunny windowsill can be ready to pot up in 7 to 14 days.
Choosing and Preparing the Cutting
The best cuttings come from the suckers that grow between the main stem and a branch. Look for straight, healthy suckers about 6 to 7 inches long. Suckers without flowers or fruit are ideal because the cutting will channel all its energy into making roots instead of ripening tomatoes. If the sucker you want already has blooms, pinch them off before you take the cutting.
Use clean scissors or a sharp knife and cut at the base of the sucker. Then strip off all leaves, side branches, and any remaining flowers from the lower portion, leaving only 3 to 5 leaves at the very top. That bare stem is where roots will emerge. Keeping just a few top leaves gives the cutting enough photosynthesis to fuel root development without losing too much water through the foliage.
Rooting in Water
Place the trimmed cutting in a clear glass jar filled with clean water. The bare stem should be submerged while the remaining leaves stay above the waterline. A clear jar lets you monitor root development without disturbing the cutting.
Set the jar in a warm, well-lit spot. A sunny windowsill, greenhouse, or any location with bright indirect light works well. Temperatures around 25°C (77°F) during the day and 20°C (68°F) at night are ideal for tomato growth, though cuttings are forgiving and will root in a range of typical indoor temperatures. Changing the water daily is ideal to keep it oxygenated and free of bacteria, but many gardeners skip daily changes and still get excellent results. Just make sure the water level stays high enough to cover the bare stem at all times.
You’ll typically see tiny white root bumps forming within 3 to 5 days. Research on tomato cuttings shows that root primordia, the earliest cellular beginnings of new roots, appear as early as 3 days after cutting. By the end of the first week, most cuttings from established, healthy plants have visible roots. If you’re working with younger or less vigorous plants, allow closer to 10 to 14 days.
Rooting Directly in Soil
If you’d rather skip the water stage, tomato cuttings also root well when planted straight into moist potting mix. Prepare the cutting the same way: 6 to 7 inches long, lower leaves removed, 3 to 5 leaves left on top. Poke a hole in damp potting soil with a pencil, insert the cutting about 2 to 3 inches deep, and gently firm the soil around it.
Keep the soil consistently moist but not waterlogged. Covering the pot loosely with a clear plastic bag or placing it in a humid environment helps prevent the cutting from wilting before roots establish. Humidity in the 65 to 75 percent range is a good target. Soil-rooted cuttings take slightly longer to show growth because you can’t see the roots forming, but a gentle tug after 10 to 14 days that meets resistance means roots have taken hold.
Do You Need Rooting Hormone?
No. Tomatoes root readily without any added hormone. Their stems naturally contain enough auxin, the plant hormone responsible for triggering new root growth, to get the job done on their own.
That said, rooting hormone does speed things up if you want faster or more abundant roots. A study published in BMC Plant Biology found that tomato cuttings treated with auxin produced nearly 8 times more root primordia at 3 days compared to untreated cuttings. By day 5, treated cuttings had 4 times more roots and those roots were twice as long. So while rooting hormone is completely optional, a quick dip in powdered or gel rooting hormone before placing the cutting in water or soil gives a measurable boost.
Best Light and Temperature Conditions
Cuttings need light to photosynthesize, but too much direct sun can cause wilting before roots develop. Bright, indirect light is the sweet spot. If you’re using grow lights, moderate intensity works best. Research on tomato seedlings found that a light level of about 240 µmol/m²/s (roughly equivalent to a bright spot a few feet from a south-facing window) produced the highest photosynthesis rates and sturdiest stems. At very low light levels, plants grew tall and spindly. At very high levels, photosynthesis actually declined because the excess light stressed the plant.
For most home gardeners, this translates to a simple rule: place your cuttings where they get plenty of light without baking in full afternoon sun. A windowsill with morning light, a spot under a fluorescent or LED shop light for 12 hours a day, or a shaded area of a greenhouse all work well. Keep daytime temperatures in the low to mid 70s°F (around 22 to 25°C) and nighttime temperatures above 65°F (about 18 to 20°C).
When to Transplant
Once roots reach about 1 inch long, the cutting is ready to move into soil. For water-rooted cuttings, this usually happens within 7 to 10 days. You’ll see a cluster of white roots emerging from the submerged stem. Some gardeners wait until roots are 2 to 3 inches long for extra security, but waiting too long can make the transition to soil harder because water roots are more fragile than soil-grown roots.
Pot the rooted cutting into at least a 6-inch container filled with good potting mix. Bury the stem deep, just as you would when transplanting a tomato seedling. Tomatoes can sprout roots all along their buried stems, so deeper planting creates a stronger root system. Water thoroughly after potting, and keep the soil evenly moist for the first week as the cutting adjusts.
If you plan to move the cutting outdoors, harden it off first by gradually exposing it to outdoor conditions over 5 to 7 days. Start with a few hours of filtered sunlight and work up to full-day exposure. Cuttings from established plants often catch up quickly to seed-grown tomatoes because they’re genetically mature and ready to flower as soon as they establish roots.
Which Tomato Varieties Work Best
All tomato varieties can be propagated from cuttings, but indeterminate types (the ones that keep growing and producing all season) are especially well suited. They continuously produce suckers, giving you a steady supply of cutting material throughout the growing season. Popular indeterminate varieties like cherry tomatoes, beefsteaks, and heirlooms all root quickly.
Determinate varieties (bush types that fruit all at once) can also be rooted from cuttings, though they produce fewer suckers and the cloned plants may have a shorter productive window since they’re genetically programmed to stop growing after a set number of fruit clusters. For extending your season or sharing plants with neighbors, indeterminate suckers are the way to go.