Kale is a very hardy vegetable which needs two months of cool weather to grow well. It is going to benefit from directly planting seeds in the ground. You can sow seeds in March to June in regions with cool summer for harvest in fall.
If you live in a warm-summer region, plant kale in late summer for harvest in late fall or early winter. Kale’s botanical name is Brassica oleracea acephala and it is a biennial plant that is grown as annual plant in order to harvest its tender leaves.
Whether you are a newbie or an experienced gardener, sometimes you can observe that kale is too tall. In this post you will find out why this is happening and what to do about it. Let’s dive in.
How tall does kale get?
How tall does kale get depends on the type of kale that you grow. Cavolo nero and Siberian kale can get to 3 ft tall (91 cm). Sutherland kale can grow to 4 ft tall (122 cm). Ideally, your kale plant should grow to 18 inches tall. However, if you plant seedlings close together, plant will grow taller.
Also, the height of kale depends on whether you are growing dwarf or full-sized variety. Dwarfing is a process of cultivating plants to make them significantly smaller than standard size. Dwarf kale is compact and grows to 24 inches tall (60cm).
Why kale is too tall?
There are two common reasons why your kale plant is growing too tall. If it is a mature kale plant that you are cutting back, the new growth is towering on the top. If the plant is growing tall and skinny after winter, high temperatures cause kale to bolt.
#1 Kale is towering
You need to harvest leaves from the mature plant regularly. Cut the leaves from base toward the top. That way you leave the top intact and new growth develops. So, it means that kale will grow very tall by towering from the top.
Start cutting leaves for cooking when plant is 8 to 10 inches high. You need to cut the outside leaves first. If kale gets too tall, you need to chop its head at about 4-5 inches from the soil. Alternatively, you can harvest the entire plant – cut 2 inches above the ground. The new leaves will grow in 1 to 2 weeks.
It is important that the stalk stays in a good condition. If it gets old and tough, it can start to rot. Moreover, this kale stalk is more prone to insect infestation. Even though you can keep plant alive this way, new plant is more productive, requires less work and tastes better.
#2 Kale is bolting
However, if you noticed that kale is tall and skinny, it means that plant is bolting – vegetable is going to seed prematurely. Most plants, including kale, bolt due to hot weather. Remember that kale is a cool temperature plant and temperature above 65°F causes kale to bolt and produce seeds.
Kale is a member of the cabbage family (Acephala Group) and is a biennial plant. It means that kale has a two-year life cycle. So, it is not going to flower until the second year. That means that in the first growing season when you planted kale for the first time it will produce the tender leaves.
With the temperature rises later in the same year or the following growing season, kale will flower and produce seeds. As a result, its life cycle will be complete. That is why it is completely normal for overwintered kale to bolt. If you want to grow kale as an overwintering plant, you need to plant it in late July or early August.
That way you can harvest leaves in fall and then harvest leaves and flower buds in spring. Many gardeners cut the flower buds and eat them in a similar way as broccoli heads. However, if you want just to harvest leaves, grow kale as an annual plant.
As a rule of thumb, kale needs 60 days of cool weather to mature. If you plant seedlings, it takes 55 days to start harvesting. If you plant seeds, wait for 70 to 80 days. Plant kale a month before the last frost in spring. Then harvest in summer and take out the plant. Everything should be done within one year.