Learning how to grow kale provides one of the most nutiritional vegetables. It is easy, undemanding, extremely nutritious, tolerant of heat, drought, wet, cold, and poor soil. It is full of organosulfur phytonutrients that recent research have shown to reduce the risk of cataracts, as well as cancers, especially colon and ovarian cancer.
Kale is generally a cold weather crop, which tastes sweeter after it has been touched by frost. It is a hardy enough vegetable that you can grow kale during any season and in most climates. That being said, it does not like the hotter weather as much and will turn bitter and become tough in temperatures over 80°F/26°C.
If you are growing kale direct from seed you may need up to 6 weeks before your seedlings are ready to plant. It grows well in an outdoor garden, but if you prefer to start your seedlings indoors, you can grow it in a pot or other container. The pot or container must have at least six square inches of space for the plant to grow in. Plant your seeds or starts in the center of the pot, following the same fertilization and depth as suggested below for outdoor garden planting (a good layer of compost, with seeds planted ½ inch deep). Make sure to move kale (grown in containers) into a partially shaded area when when summer arrives and temperatures exceed 80°F/26°C.
1. If you're planting during the cool season (spring months), find a spot where your kale will receive full sunshine. If you are planting during the warm season, or in a warmer climate, choose a spot with partial shade. Kale enjoys companion plants such as beets, celery, herbs, onions and potatoes, but does not grow as well if planted near beans, strawberries or tomatoes.
Kale prefers loamy, well-drained, moist (but not soggy) soil. Kale doesn't respond as well to soil that is too rich in nitrogen, so it will do best with a pH between 5.5 to 6.8. If your soil is too acidic, you can add some wood ash to sweeten it. Light, sandy soils and very heavy clay soils will give your kale a more bitter taste, but it still has the potential to grow in these environments.
2. Before planting, distribute some vegan organic fertilizer over the area you will be using and work it into the soil. Depending on the fertilizer's potency, you may want to fertilize then cover the bed and allow it to weather for one to two weeks before planting to be sure it mixes well into the soil (if strong). If you are using seasoned compost to fertilize, you should be able to simply fertilize then plant the next day.
3. When you are ready to plant in your garden, space the seedlings 12-15 inches apart in rows 16-20 inches apart. The space for direct sowing is much closer (if you are direct sowing your kale seeds, plant them ½ inch deep and approximately 3 inches apart and then thin plants to 12 inches apart when they are 4 to 5 inches tall.)
If you start seedlings inside, then do so 5-7 weeks before the last expected frost. If you're sowing seeds outside, do so 2-4 weeks before the last frost and/or anytime at least 10 weeks before the first frost of the next season. No matter when you plant, the soil temperature must be at least 40°F/5°C or higher for good germination. Place the seed at least ½ inch deep. Keep the soil around the seedling evenly moist throughout its growth, but allow the top layer of soil to dry between watering.
A note on quantity: If you're going to be using kale on a regular basis, you'll want to have at least 3-4 plants per household member. This will produce A LOT of kale!
4. No matter the shape of the stem, set the transplants perpendicular to the ground so they will grow straight up, and place them deep enough to support the plant, but no further than the base of their first leaves. We often plant our kale 12 to 15 inches apart and then stagger the rows or plant on a diagonal so we can shrink the space between rows. Experiment with what works best in your garden. When we first learned how to grow kale, we tried just planting just a few transplants in order to get an idea of how they would grow in our area.
Keep your plants well watered. Along with cool temperatures, kale also enjoys moist soil. Keeping the soil most will also help keep the leaves sweet and crisp.
Side dressing (fertilizing along the rows) with compost throughout the growing season will help keep your kale producing. You can do this approximately every 6-8 weeks. Well seasoned compost works well.
If you're having issues with dirt sticking to and rotting your kale leaves, you can put mulch (such as straw or grass) around the kale once it is at least six inches high.
Kale is usually ready for harvest 70-95 days from seed and 55-75 days from transplanting, depending on the variety you are planting. Check the seed packet for specific times. You can begin to cut individual leaves off the kale when the plant is approximately 8 to 10 inches high, starting with the outside leaves first. If you decide to harvest the entire plant, cut the stock two inches above the soil and the plant will sprout new leaves in 1 to 2 weeks.
Make sure to harvest kale leaves before they become too old and tough. If you can't eat the kale leaves fast enough and they begin to turn brown, pull the old leaves off, and compost them, to free the plants of insect attractants and unnecessary energy drains.
You can also pick kale regularly and store it in the fridge for up to a week. If you choose to do so, keep it lightly moist and place it in a bag, but unsealed, in the crisper bin.
Kale is relatively good at resisting disease. Giving your plants the nutrients they need and picking off any weathered leaves will help reduce insects found in your garden. Some of the specific pests that can harm kale are below.
If you have further questions about how to grow kale, you can reach us from our Contact Us page.