Learning How to Harvest Kale
If you plan on picking baby kale leaves, you can start harvesting kale just a few weeks after planting it. To use full-sized leaves, which are about the size of your hand, you should wait about three months after planting seeds or about two months after planting a transplant. When you pick kale, harvest the outer leaves first, leaving the smaller, inner leaves to keep growing. Don't cut the stem off at the top, as doing so will put an end to any growth.
There is a right way and a wrong way to harvest kale. If you harvest kale correctly, the plant will continue to grow and produce leaves. If you harvest it incorrectly, the plant will stop growing.
Kale produces leaves on a stem. The leaves grow from the top of the stem and the stem will continue to grow taller and to make more leaves throughout the plant's life.
When picking kale, it's important to pick the oldest leaves first. Those are the leaves nearest the bottom of the plant. They are usually the biggest leaves.
If you cut the plant off at the top or harvest the smaller leaves growing in the center, it is very likely that you will kill the plant. You need to leave that center area at the top of the stem for the plant to keep on producing.
The video from Edible Urban Farm shows you quite simply how to harvest kale leaves correctly. Along with leaving the smaller, central leaves, it's important not to harvest too much of the plant at a time. Pick a few leaves from each plant, leaving at least one third of the leaves intact.
Picking the oldest leaves from the kale when you harvest also ensures that you'll be able to use up the entire plant. If you let the leaves sit on the plant for too long, they'll turn yellow, according to Our Green Thumb Community Garden. Older leaves are also more likely to be tough.
When to Harvest Kale
When kale is ready to harvest depends on how you planted it and how you plan on preparing it. It takes a lot less time for baby kale to be ready for harvest than it does for mature kale leaves to be ready.
If you plant kale from seeds, you can expect the full-size plants to be ready for harvest about 70 days after planting, according to Harvest to Table. Since transplanted kale seedlings have a head start on seeds, you can expect those plants to be ready to harvest around 55 days after planting.
Picking Baby Kale
The timeline for harvesting baby kale is a lot shorter than for harvesting full-sized kale leaves. According to the Napa Master Gardener, you can usually start to harvest baby sized kale leaves about 25 days after planting the seeds.
Usually, baby kale is ready for picking and eating once the plants are about four inches tall.
The video above from Renee's Garden Seeds shows you an easy way to harvest baby kale leave. Simply gather the small plants into handfuls and cut the stems. Leave about two inches worth of stem on each plant, so that the leaves can grow back.
Harvesting After a Frost
Burpee Seeds recommends waiting to harvest your kale plants until after a frost. While freezing temperatures often kill many types of plants, a frost actually improves the taste of kale.
According to the NC State University Cooperative Extension, a frost will increase the amount of sugar in a kale plant's leaves. Once you harvest those leaves for eating, the overall flavor is much sweeter.
If you hope to wait for a frost to harvest any kale, you'll have to get the timing right. That means transplanting seedlings into your garden about six weeks before the first frost in your area. You'll want to direct sow seeds about three months before the first frost.
Another option is to harvest some leaves from the plant before the frost, then wait to harvest additional leaves afterwards. You'll be able to compare the difference in taste between the leaves you harvested early and those you harvested later. You'll also be able to get more out of your kale plant if you plant and harvest it earlier.
Prolonging the Harvest
Even though kale can withstand a bit of cold and a frost improves its flavor, it won't make it through winter in every area. If you live in an area that sees temperatures that are much lower than 32 degrees Fahrenheit on a regular basis, you can extend the life of your kale plants and their harvest period.
Row covers, hoop houses and cold frames help you protect your kale plants from very cold temperatures. The covers or frames act as insulation for the plants. The simplest way to protect your kale is to drape a tarp over it and secure the tarp with some hay, according to the Old Farmer's Almanac.
To harvest, simply reach under the cover or open the frame and pick or cut away a few leaves. You can also let the kale alone until the spring, when it will resume growth again.
Harvesting in the Heat
Kale just doesn't like the heat. Its leaves get tough and bitter when temperatures are in the high 80s or 90s. That means if you plant kale in the spring in a hot climate, by the mid-summer, it's going to be a tough, barely edible mess.
Desperate times call for desperate measures, and there is a way to harvest kale in the heat of summer so that it will return again once the weather cools down.
The video from the Rusted Garden shows you how to cut back your kale plants hard in the summer. Instead removing just a few leaves from the plant, you remove up to 90 percent of them. Whether you eat or compost them depends on how tough or worn out the leaves are.
Leave a few leaves at the top of the stem, so that the plant can continue to grow into the fall and winter.
When it comes to harvesting it, kale is a pretty flexible plant. You can harvest it young to enjoy tender, raw leaves or wait until a leaf is about the size of your hand to use in cooking. Timing depends on when you plant the kale and what the weather is doing in your area.