Most gardeners grow tomatoes from nursery plants or from seed. But you also can propagate them via cuttings. This allows you to create an exact copy of a particular tomato plant you like. Late spring is the best time to take a cutting, though it can be attempted at any point with indoor-grown tomatoes. Here’s how: Select a sucker coming off the main stem, and cut off a portion that’s 6 to 8 inches long.  Remove any buds or flowers on the cutting, along with the leaves on the lower half of the stem.  Plant your cutting in a small container filled with soilless potting mix, and evenly moisten the mix. Place it in a warm spot with bright, indirect light. Keep the mix moist. Roots should develop within two weeks. You’ll know they have strong roots when you can gently tug on the cutting and feel resistance.