QUESTION: Can I take a cutting of kale and plant it? Can I grow kale from a leaf? -Lea B.
ANSWER: While you can’t grow kale from a single leaf, you can grow it from a cutting of a robust side stem that has several leaves. Use clean, sterilized shears to trim the cutting off where it meets the main stem of the plant.
Remove all but the top leaf, and if the top leaf is large, cut its top half off, leaving the bottom half attached to the stem. (Pruning the cutting this way encourages the kale to focus its energy on creating roots instead of caring for its foliage in the beginning stages of propagation.) Trim the stem at the bottom at a 45-degree angle just under a leaf node. Then plant your cutting in a container with drainage holes that has been filled with moist potting soil.
Find a sunny windowsill for your cutting where it will be safe from drafts and pets. Use a spray bottle to regularly mist the soil, keeping it damp but not actually wet. The cutting will create new roots within about three weeks. It takes three months for the cutting to grow into a plant large enough to transplant into your garden, and it will need to be gradually introduced to the outdoor climate and direct sunlight through the hardening off process. For details on moving your cutting outdoors, refer to our article Hardening Off Plants: Common Reader Questions and Answers.