Pests. Fill the pots about 3/4 full with the same growing medium you used to germinate the seeds. There are a number of perennial kales often known as cottagers kale: Daubenton kale, Taunton Deane kale… A single, fully-grown kale plant will need a container that is about 12 inches (30 cm) deep and equally wide. Kale is a very versatile vegetable and can be eaten at all stages of maturity, providing baby leaf crops in summer, then through autumn and winter into spring. Kale will grow in a 6-inch (15cm) container. Give it a sunny position in order to encourage stronger growth during the dark winter months. It stands up to frosts with ease and thrives in just about any well-drained, fertile soil. The kale plant is a non-heading, cabbage like plant with curly or straight, loose blue-green or purple leaves. Plant in the ground leaving enough space for them to grow, and if growing in a container I choose a fairly large one. Kale Pests and Diseases. Kale is usually grown as as an annual plant, harvested after one growing season and can reach a height of 1 m (3.3 ft). Their flavor is mild and nutty, growing sweeter after frost. Hardy kale is the most reliable crop of the cabbage family. Kalettes require high fertility and a long growing season. For this reason, it’s often referred to as winter kale. Seeds become less viable as they age, germination rates drop down incredibly. Rather than harvest the wild one, I suggest growing a very close relative. Where to Grow Kale . Harvesting . Move kale grown in containers into the cool shade when the weather warms to extend the season. Kale will grow from early spring until early winter and it even favors temperatures that get down to 20 degrees Fahrenheit (-6° C) or so. Kale can be attacked by cutworms, cabbage loopers, and imported cabbage worms. Like cabbage, kale grows best when well-fed. Seeds are a little more expensive, since kalettes are a trademarked novelty vegetable. Be sure to choose pots that have drainage holes at the bottom. I enjoy eating it throughout the long kale season, but kale that is exposed to frost will have a sweeter flavor. How to grow kale from seed in hydroponics: Kale Seeds germinates finest at temperatures between 60 and 75 degrees Fahrenheit, they can be germinated at lower temperatures, as low as 40 Fahrenheit but much slower and with a lower germination success rate. Plant kale on 8-inch (20cm) centers in large containers. Kalettes, also known as BrusselKale and Lollipop Kale, have tall erect stems ringed with small rosettes of kalelike leaves. Container Growing Kale.