Rooting tomato cuttings takes two to four weeks and works best with young, healthy stems cut from the growing tip

You can grow a new tomato plant from a cutting taken from an existing plant without waiting for seeds to germinate. The cutting develops roots in either water or soil, and the rooted cutting becomes a full plant ready to transplant into a pot or garden bed. Success depends on using the right part of the plant, keeping the cutting moist while roots form, and maintaining warmth around 65 to 75 degrees Fahrenheit.

The fastest and easiest method for most home growers is rooting in water, where you can watch roots develop and move the cutting to soil once they reach half an inch long. Rooting in soil works too and skips the transplant step, but requires more attention to moisture and is harder to monitor.

Key Takeaways

  • Cut a four- to six-inch stem from new growth at the tip of the plant, using a clean knife or pruners to make a straight cut just below a leaf node.
  • Remove the lower leaves so at least two inches of bare stem sits below the water line or soil surface, where roots will emerge.
  • In water, change the water every two to three days to prevent rot, and move the cutting to soil once roots reach half an inch long.
  • In soil, use a pot with drainage holes filled with moist seed-starting mix or potting soil, and cover the pot with a plastic bag to hold humidity until roots form.
  • Keep the cutting in bright, indirect light and temperatures between 65 and 75 degrees Fahrenheit for the fastest root development.

Choosing and cutting the right stem

Select a healthy stem from the newest growth at the tip of the plant, not from old woody branches near the base. The stem should be soft and flexible, not hard or brown. A four- to six-inch length is ideal—long enough to handle but short enough that the cutting does not use up all its energy before roots form.

Use a clean, sharp knife or pruning shears to cut the stem at a 45-degree angle just below a leaf node, which is the small bump on the stem where leaves attach. Leaf nodes are where roots emerge, so cutting below one gives the cutting the best chance. Wipe your blade with rubbing alcohol or a clean cloth before cutting to prevent spreading disease from one plant to another.

Take the cutting in the morning when the plant is full of water, not in the heat of the afternoon. This gives the cutting the most moisture to survive the stress of being separated from the plant.

Preparing the cutting for water rooting

Strip off all leaves from the bottom two inches of the stem using your fingers or a clean knife. These lower leaves would sit underwater and rot, which introduces bacteria and fungus that kill the cutting. Leave the top two or three leaves intact—the cutting needs them to make food through photosynthesis while roots develop.

If the remaining leaves are very large, cut them in half with a clean knife. Smaller leaves lose less water through their surface, which helps the cutting survive until roots form and can replace that water.

Fill a glass or jar with room-temperature water. Tap water works fine for most growers, though some prefer to let it sit overnight so chlorine can evaporate. Place the cutting in the water so the bottom two inches are submerged and the remaining leaves are above the water line.

Rooting in water: daily care and timing

Set the glass in bright, indirect light—a windowsill that does not get direct sun all day works well. Direct sun heats the water and encourages algae growth, which competes with the cutting for nutrients. A north-facing or east-facing window is ideal.

Change the water every two to three days by pouring it out and refilling with fresh room-temperature water. Stagnant water becomes low in oxygen and develops bacteria. If you see brown or slimy growth on the stem, change the water when ready and trim away any mushy parts with a clean knife.

Roots usually appear within two to three weeks as small white bumps at the base of the stem, then grow into thin white strands. Once roots reach half an inch long, move the cutting to soil. Waiting longer than this makes the transition to soil harder because water roots are fragile and different from soil roots.

Rooting in soil: setup and moisture control

Fill a small pot with drainage holes with moist seed-starting mix or potting soil. Do not use garden soil, which compacts and holds too much water. Poke a hole in the soil with your finger about two inches deep, then insert the prepared cutting so the lowest leaves sit just above the soil surface.

Firm the soil gently around the stem so it stands upright and makes good contact with the soil. Water lightly until water drains from the bottom of the pot, then let the soil dry slightly before watering again. The soil should feel like a wrung-out sponge—moist but not soggy.

Cover the pot with a clear plastic bag or a clear plastic dome to trap humidity around the cutting. This reduces water loss through the leaves while roots develop. Prop the bag so it does not touch the leaves, and open it for five minutes every two days to let fresh air in and prevent mold.

Light, temperature, and when to transplant

Place the pot in bright, indirect light—the same conditions as water rooting. A grow light placed six inches above the cutting works well if you do not have a bright window. Keep the temperature between 65 and 75 degrees Fahrenheit. Cooler temperatures slow root development; warmer temperatures can cook the cutting.

Roots develop in two to four weeks. You can check progress gently by loosening the soil around the stem with a small stick—if you feel resistance, roots are forming. Once you see new leaf growth at the tip, roots are established enough to remove the plastic bag.

After another week of growth without the bag, the cutting is ready to move to a larger pot with regular potting soil or directly into the garden if outdoor temperatures stay above 50 degrees Fahrenheit at night. Harden off the cutting by placing it outdoors in shade for a few hours each day for three to five days before planting it in full sun.

Common mistakes and how to avoid them

Cutting from old wood instead of new growth: Old stems root slowly or not at all. Always cut from the soft, green tip growth.

Leaving lower leaves on the cutting: Submerged leaves rot and introduce disease. Strip them completely before placing the cutting in water or soil.

Using tap water that is too cold: Cold water shocks the cutting and slows root development. Let water sit at room temperature for an hour before using it.

Overwatering soil-rooted cuttings: Soggy soil causes the stem to rot before roots form. Let the top half inch of soil dry between waterings.

Placing the cutting in direct sun: Direct sun heats the water or dries out the soil too fast. Bright, indirect light is enough for the cutting to survive until roots form.

Frequently Asked Questions

Can I use rooting hormone to speed up the process?

Rooting hormone is not necessary for tomato cuttings—they root reliably without it. If you choose to use it, dip the cut end in powder rooting hormone before placing the cutting in water or soil. Follow the product instructions for the amount. Rooting hormone may shorten the timeline by a few days, but the difference is small.

What if the cutting wilts or the leaves turn brown?

Wilting usually means the cutting is losing water faster than it can replace it. Move it to a shadier spot, increase humidity by covering it with a plastic bag, or mist the leaves with water once a day. Brown leaves often mean the cutting is too wet or the water is stagnant—change the water when ready and trim away any mushy parts.

How many cuttings should I take from one plant?

You can take several cuttings from a healthy plant without harming it, but do not remove more than one-third of the plant at once. Taking too many cuttings stresses the parent plant and slows its growth. Space your cuts along the stem so the plant keeps its shape.

Can I root cuttings from a store-bought tomato plant?

Yes, store-bought plants root just as well as homegrown ones. Take cuttings from the newest growth at the tips of the stems and follow the same steps. This is a good way to preserve a variety you like or extend the growing season if you take cuttings in late summer.

What temperature is too cold for rooting?

Below 60 degrees Fahrenheit, root development slows dramatically or stops. If your home is cool, place the cutting on a heat mat set to 70 degrees Fahrenheit, or move it to a warmer spot like the top of a refrigerator or near (but not touching) a heat source.