Ferguson: It’s not easy growing greens

Published 12:46 pm Friday, October 15, 2021

Greens such as turnips, mustards, collards, and kale can be planted from mid-July through early November and again from late January through early May. Make multiple plantings to spread out the harvest.

Turnips, mustards, collards, and kale are all in the Brassicaceae or mustard family. It’s a good idea to rotate what you plant in a certain area of the garden by plant family for disease management purposes, so these can be put in a spot where you’ve had plants in the nightshade (tomatoes, peppers, eggplants, potatoes), legume (beans, peas), or cucurbit (cucumbers, melons, squash) families, for example.

Soil pH for greens should be between pH 6 and 7. If your soil hasn’t been limed in the recent past, some lime may be needed. A soil test can tell you if you need lime, as well as how much phosphorus, potassium, and other nutrients are needed. If you’re in a hurry to plant and don’t want to take time for a soil test this time, you can apply and incorporate 10 pounds of 8-8-8 or six pounds of 13-13-13 per 1000 square feet of garden prior to planting.

“Florida Broadleaf” is a popular mustard variety that is well-suited to Louisiana. Other options include “Green Wave,” “Red Giant,” “Savannah,” and “Southern Giant Curled.” “Tendergreen” is more heat tolerant than some other mustards.

Collards and kale are very closely related to each other and are highly cold tolerant. They can withstand temperatures of 14 degrees Fahrenheit if hardened off adequately. Collard varieties to consider include “Champion,” “Flash,” “Georgia” (a.k.a. “Creole”), “Top Bunch,” and “Vates.” If you want something that’s ornamental as well as edible, look into “Redbor” kale. This was named a Louisiana Super Plant several years ago.

“Alamo” and “Seven Top” are turnip varieties to plant if you’re only interested in greens. Consider “Just Right” if you want both greens and roots. “Purple Top White Globe,” “Tokyo Cross” and “White Lady” turnips are grown largely for the roots but will produce greens, too.

You can space mustard and turnip seeds about three inches apart and collard and kale seeds six to 12 inches apart.

Sidedress the plants with fertilizer three to four weeks after planting. Five pounds of calcium nitrate or two pounds of 33-0-0 per 1,000 square feet are options for sidedressing. If you only have 8-8-8 or 13-13-13, you can use the same amount that you used before planting to provide a similar rate of nitrogen.

Watch for aphids or “plant lice.” If you have a problem with these, you can look for an insecticide that is labeled for the type of green that you’re growing and contains acetamiprid, malathion, or insecticidal soap as the active ingredient. Be sure to follow label instructions when using any pesticide.

Let me know if you have questions.

Dr. Mary Helen Ferguson is an Associate Extension Agent with the LSU AgCenter, with horticulture responsibilities in Washington and Tangipahoa Parishes. Contact Mary Helen at mhferguson@agcenter.lsu.edu, 985-839-7855 (Franklinton) or 985-277-1850 (Hammond).