How to Grow Kale & Chard in Pots

About Kale and Chard

• Kale and chard are both excellent bookend-season plants, generally preferring cooler weather for best taste and growth performance. However, they will continue to grow -- slowly -- during hot weather. Leaves can be harvested continually from the outer edges of each plant, because new leaves regenerate from the center crown throughout the season. Spring crops of kale can be sown directly in the pot four to six weeks prior to the last frost, while chard should be sown two to three weeks before the last frost. In fall, seeds of either plant should be sown two to three months prior to the first killing frost. Both plants grow best in full sun or with at least eight hours of sunlight daily.

Soil and Container Selection

• Always keep two key points in mind when planting vegetables in containers: don’t crowd them, and don’t use garden soil. Kale has a relatively wide spread, from 1 to 3 feet across, and will need at least a 2-gallon pot. Chard is narrower, rarely spreading more than 1 foot across, and will do well in a smaller 1-gallon container. Use a large, half-barrel type container to grow more than one plant, and space plants at least 1 foot apart. A homemade or commercial potting soil mix is always preferable to garden soil, which is heavier and compacts much more easily than the fluffy, lightweight mixes formulated for pots. These mixes are usually made up of milled peat moss, which provides aeration and moisture retention, and compost, which provides weight and nutrients. If purchasing a soil mix, check to see if it includes a slow-release fertilizer, because this will affect fertilization rates. Plants grown in pre-fertilized mixes shouldn’t need feeding for at least eight to 10 weeks, after which they only need feeding every two to three weeks. Use a balanced, all-purpose plant food such as 20-20-20, and apply at a rate of ½ to 1 tablespoon per gallon of water at each feeding.

Watering

• As a rule, container-grown plants require more frequent watering than plants grown in the ground, and kale and chard are no exception. Soil in containers is more exposed to air, and water evaporates rapidly both from the plant and from the soil itself. Plastic pots dry out more slowly compared with ceramic containers, but any container should have drainage holes in the bottom. Container-grown kale and chard will probably require watering every day in the summer or even twice daily in hot weather. Irrigate until drainage noticeably slows from the top of the pot, which indicates soil has become saturated. Water flowing through the drainage holes is not necessarily an indicator that a pot is well watered, because extremely dry pots will allow water to flow straight down the sides of the pot and out the holes.

Pest Control

• Chard is rarely bothered by insects. Kale is also relatively untroubled, but it can attract more pesky critters, especially when young, such as cabbage looper caterpillars, aphids, flea beetles, and cabbageworms. Pest problems are at their peak in late summer into fall, so as the year wanes, be extra vigilant to avoid excess munching. Most pests of container plants, especially caterpillars, are well controlled through handpicking, while aphids can be dislodged with a strong stream of water. Flea beetles are rarely a problem of container plants, although they are harder to control when they do appear. They are parasitized and preyed upon by a variety of beneficial insects, so encourage the residence of lacewings, ladybugs, damsel bugs and big-eyed bugs by growing annuals like dill (Anethum graveolens) or marigolds (Tagetes spp.), or perennial chamomile (Chamaemelum nobile), which is hardy U.S. Department of Agriculture plant hardiness zones 6 through 9.