Grow Tomatoes From Tomato, Root Slices, Seeds, and Cuttings This Weekend

You do not have to buy seed or transplants to grow tomatoes from tomato, the three DIY ways work, and yes, you can start viable plants this weekend. I recommend rooting a softwood cutting first for the fastest, most reliable results in midsummer, but I also show exact steps for slices and saved seeds if that is what you have on hand.

By the end of this guide you will be able to start new tomato plants from a tomato slice, fresh seeds, or a softwood cutting, and know exactly when to transplant them into your bed.

Get the short answer, can you grow tomatoes from a tomato and which method I favor

Quick compare, slice versus seed versus cutting, one line pros and cons for busy gardeners

• Slice, pros: fast and uses one ripe tomato, cons: lower success, easy rot if too wet.
• Seed, pros: lots of plants from two tomatoes, cons: fermenting step takes time and seeds vary genetically.
• Cutting, pros: clones the parent, fastest dependable rooting in midsummer, cons: requires a healthy mother plant.

Gather what you need, exact quantities for slices, seeds, and cuttings

Supplies for the slice method

• One ripe tomato, not bruised or rotten.
• One small pot, 4 inches wide and 3 to 4 inches deep.
• 3/4 cup seed starting mix per pot.
• One clear plastic bag to tent over the pot.

Supplies for the seed method

• Two ripe tomatoes for seed extraction.
• One bowl and a fine mesh strainer.
• One 12-cell tray, 2 inches deep cells.
• 2 cups seed starting mix to fill the tray cells to 1 inch below rim.

Supplies for cuttings

• One healthy branch from a strong tomato plant, free from disease.
• One 3 inch pot per cutting.
• 1 cup rooting hormone, optional, a small pinch used per cutting if powdered.
• 1 cup perlite mix, enough to fill each 3 inch pot to 1 inch below rim.

Prepare the medium and tools, soil mix, sanitation, temperature and light targets

Make the mix

Mix 3 parts peat moss or coco coir, 1 part finished compost, and 1 part perlite. For a 1 quart batch use 3 cups coir, 1 cup compost, 1 cup perlite. Fill pots to 1 inch below the rim so water drains and you can topdress. I lost seedlings once to compacted mix, so light and airy is key.

Sanitize tools and containers

Use a bleach solution of 1 part household bleach to 9 parts water to disinfect pots and metal tools. Soak plastic pots and metal clippers for 5 to 10 minutes, then rinse with clean water and air dry. Wipe off plant-clean knives between cuts. Cleanliness cuts rot risk dramatically.

Set temperature and light

Aim for soil 70 to 75 degrees Fahrenheit for fastest rooting and germination. Use a seedling heat mat if your room is cooler. Provide 12 to 16 hours of bright light or indirect sun each day, keeping plants 2 to 4 inches from a fluorescent or LED grow light. In zones warmer than 6b, watch for overheating, keep temps closer to 70 F, and in colder zones expect slower roots and add bottom heat if possible.

Plant a tomato slice, step by step with timing and placement

Cut details, slice thickness 1/4 inch, remove only outer seeds if you prefer, plant slice flush with soil or slightly buried at one edge

1. Cut a fresh slice about 1/4 inch thick from the middle of the tomato, not the stem end.
2. If you prefer fewer seeds, gently scrape outer seeds away with a spoon, but do not wash the slice, the pulp helps root formation for this method.
3. Place the slice flush on the prepared surface, or tuck one edge 1/8 to 1/4 inch into the mix so it makes contact with moist soil.

Potting and cover, press into a 4 inch pot, mist, cover loosely with clear bag to hold humidity for 7 to 10 days

Press the slice snugly into 3/4 cup of mix in a 4 inch pot. Mist once with a spray bottle until the surface is evenly moist, not waterlogged. Cover the pot loosely with a clear bag or plastic dome to raise humidity. Keep the soil at 70 to 75 F and check daily. Remove the cover briefly each day for 5 minutes to prevent mold buildup.

When to transplant from slice to larger pot, 3 to 4 true leaves or roots visible at pot bottom

Transplant the slice into a 6 to 8 inch pot when you see three to four true leaves, or when roots show at the pot bottom, usually 3 to 4 weeks. Harden the plant for outdoor planting by exposing it to increasing outdoor time over 7 to 10 days. Move to the garden only after the last frost date and when soil is 60 F or warmer in central Ohio or your local frost-based timing.

Start seeds from a tomato, clean, ferment, dry, and sow with exact timing

Extract seeds, ferment 48 to 72 hours in a jar at room temperature, rinse and dry on a paper towel for 3 days

1. Slice two ripe tomatoes and squeeze seeds and gel into a jar. Add 1/4 cup water, cover loosely, leave at room temperature.
2. Ferment 48 to 72 hours, stirring once a day. You want a thin film of mold and the gel to separate from seeds, that indicates fermentation worked. Do not let it go longer than 72 hours or seeds may be damaged.
3. Rinse the seeds in a fine mesh strainer until water runs clear. Spread seeds on a paper towel and air dry for 3 full days, stirring twice a day to avoid clumping.

Warning, if the fruit came from a diseased plant, especially blight, do not save those seeds. See my guide on blight on tomatoes, identify, treat, and prevent for details on disease risks.

Sow depth and spacing, press seeds 1/8 inch deep, 2 to 3 seeds per cell, thin to the strongest seedling

1. Fill a 12-cell tray with seed starting mix, water until moist but not soggy.
2. Place 2 to 3 seeds per cell and press gently 1/8 inch into the mix. Cover lightly with mix or vermiculite.
3. Keep soil 70 to 75 F, light after sprout, 5 to 10 days. Thin to the strongest seedling by snipping weaker stems at the soil line when true leaves appear.

Root a softwood cutting if you want identical plants faster

Choose a shoot, take a 4 to 6 inch cutting with two sets of leaves, remove lower leaves, insert 1 to 2 inches into moist perlite mix

1. Select a healthy nonflowering side shoot, 4 to 6 inches long, with two sets of true leaves.
2. Cut at a 45 degree angle with a clean blade, remove the lower leaves leaving 2 leaves at the top, and trim any flower buds.
3. Dip the cut end into a pinch of rooting hormone if using, then insert 1 to 2 inches into moist perlite in a 3 inch pot. Firm the perlite around the stem to remove air pockets.

Rooting help, use 1/4 teaspoon diluted fertilizer after first true roots, expect roots in 10 to 21 days

Keep the perlite moist and the soil at 70 to 75 F. Expect roots in 10 to 21 days. After roots are 1 inch long, pot up into a 4 to 6 inch pot with the mix above. Use 1/4 teaspoon of a balanced soluble fertilizer per gallon of water only after the first true roots form, then feed lightly every two weeks. For container guidance see how to grow tomatoes in containers and how to grow tomatoes in pots for pot sizes and supports.

Care

Water newly started plants gently, 1/4 to 1/2 cup per 4 inch pot when the top 1/2 inch of mix is dry. Avoid overwatering, the most common failure is rot from constant wetness. If you see fuzzy white or gray mold, remove the cover and let the surface dry slightly, then repot into fresh mix if rot persists.

Keep plants under 12 to 16 hours of light and maintain soil at 70 to 75 F. Harden seedlings and cuttings outdoors for 7 to 10 days before transplanting to the garden. Transplant into the bed after the local last frost date when night temperatures are consistently above 50 F and soil is 60 F or warmer. In USDA zone 6b, that usually means late May, but always check your local frost date and soil thermometer.

Once in the garden, space determinate varieties 18 to 24 inches apart, indeterminate 24 to 36 inches apart, and plant deeply up to the first set of true leaves to encourage strong roots. Topdress with compost and follow feeding with guidance from tomato plant fertilizer when fruit sets.

FAQ heading

Can any ripe tomato give good seeds for next year?

Yes, but only if the parent plant was healthy. Ferment seeds 48 to 72 hours to remove the gel that inhibits germination. If the parent had disease signs, especially blight, do not save those seeds, and clean tools before collecting seeds.

How often should I mist a tomato slice under plastic?

Mist once a day to keep the surface moist but not soaked, and open the bag briefly each day to exchange air. If you see mold, remove the slice, replace mix, and try again with drier surface conditions.

Will cuttings fruit in the same year?

Cuttings can grow to fruiting size in 6 to 10 weeks in midsummer if root and sun conditions are good. Root in 10 to 21 days, pot up, and give full sun and regular feeding. They will fruit on the same season when started in midsummer.

When should I transplant a seedling outdoors in colder or warmer zones?

Transplant after your last frost date when nights are above 50 F and soil is at least 60 F. In colder zones wait 2 to 4 weeks longer; in warmer zones you can move plants out 1 to 3 weeks earlier if nights stay warm. Always harden off plants first for 7 to 10 days.