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How to Grow Kale

If you want to grow kale indoors, you need to think about:

  • Where to grow it. 
  • Which type of kale to grow. (e.g. flat kinds of kale, curly kale, perennial kale, etc..)
  • When you wish to harvest your crop. (As sprouted kale seeds, micro-greens, baby leaf kale, or for more mature leaves.)
  • The requirements for successful germination. (How to grow kale from seed indoors.)
  • And how to care for and harvest your kale. 

Read on to explore each of the above issues and learn why growing kale indoors is such a fun and easy thing to do.

Growing Kale Indoors

Where to Grow Kale Indoors

Kale is a leafy green vegetable to grow indoors. Though this is a hardy vegetable that can thrive outdoors, it can also work well for indoor gardeners. However, to grow kale indoors you do need to understand the conditions it requires. 

Kale needs moderate amounts of light but may do better when it is protected from the harshest direct sun during the hottest part of the day in summer. Through glass, the sunlight can be intense. 

In winter, however, natural light may not always be enough when growing indoors, so growing kale under grow lights might be a good idea. Though not always essential, grow lights can make growing kale indoors in winter even easier than it already was.

As long as you choose a suitable spot inside your home, that does not get too hot or fluctuate too wildly in temperature, you should find kale easy to grow all year round. 

Types of Kale to Consider

Of course, as well as finding a suitable spot inside your home to grow kale indoors, you will also have to think carefully about which type of kale you want to grow. 

There are many named cultivars of kale to consider, most biennial but some truly perennial in their lifecycles. 

Broadly, these cultivars can be divided into flat-leaved varieties and varieties of curly kale. Most kales are green but there are also purple types to choose from, some truly ornamental kales that are as pleasing to the eye as any flowering houseplant. 

All kales are easy to grow. So you could easily select several so you have a variety to look at and harvest throughout the year. 

Deciding When to Harvest Kale

When you are selecting a variety or varieties of kale to grow indoors, you also need to think about when you want to harvest your crop. You can:

  • Eat sprouted kale seeds.
  • Grow kale for only a very short period and eat kale seedlings as micro-greens. 
  • Harvest small kale leaves as baby leaf kale for salads etc…
  • Or pot up kale seedlings into larger pots to grow them on for more mature kale leaves, to eat raw, or to enjoy in cooked recipes. 

Most varieties of kale can be used for any of these purposes. But some varieties will be better to grow to maturity indoors than others. So think about this when selecting kale seeds to sow. 

Sowing Kale Seed

Kale seeds are typically sown to grow indoors between March and June, just as they are when you are transplanting the seedlings to an outdoor garden. 

But kale can also be sown after midsummer, and potentially throughout the fall and winter months when growing kale only for a short period inside for micro-greens or baby leaves. 

Seeds sown in spring will provide harvests of mature leaves from fall onwards. Early summer sowings will provide harvests of mature leaves through winter and into early spring. 

But remember, seeds sown at any time can also be harvested just a few days to weeks later as sprouted seeds or micro-kale. 

Sow seeds into trays, modules, small pots, or other containers, making sure that they are around 1cm deep. Or, for sprouted seeds, place them into any moist medium until they sprout. 

A general-purpose peat-free potting mix will generally make a good growing medium for kale. You can also make some potting mix using homemade compost for a great eco-friendly solution. 

If you are not growing micro-greens and want to grow on the kale plants indoors, pot them on individually as they grow. 

Note that a full-sized mature kale plant will eventually need a pot or other container around 40cm across. A kale planter or a container for growing kale in pots should be sufficiently deep to allow the roots to develop if you want to grow the plant to maturity. 

You can also buy kale starts if you don’t wish to grow from seed. But growing kale from seed is easy and quick so the extra expense is not typically worthwhile. 

Caring for Kale and Harvesting 

How often to water kale depends on the environmental conditions. In cooler temperatures with lower light levels, kale will tend to require less water. It will need more water when it is bright and warm. 

But remember that kale in containers will need more water, so regular watering to keep the soil moist will be essential when growing kale indoors. 

Consider growing kale alongside pea shoots in a pot or other container. The peas will help provide the nitrogen that kale plants need to grow strongly. This is one example of companion planting that can make it easier to grow kale indoors. 

Sprouted seeds are simply plucked up and eaten entirely in salads or sandwiches. 

Micro-kale is harvested before the kale gets its true leaves, while still very small. It is usually harvested with a pair of scissors. 

Baby leaf kale is harvested as individual leaves or with scissors at a slightly later stage, but usually while plants still only have a few true leaves. 

Leaves from mature plants are harvested from the bottom, working upwards, as required, while the rest of the plant continues to grow. 

Whichever stage you decide to harvest, you will soon discover exactly how to grow kale at home and how easy and rewarding it can be.