We are entering the season to plant spring vegetable gardens. As the saying goes, “Plant your potatoes on St. Patrick’s Day” or others say to go with Good Friday. Either way, these cool season vegetables can be planted now. But be cautious with your plants, they could be injured by late freezing temperatures or frost events.
Spring Crops
Vegetable gardens can be worked in the spring as soon as the ground is dry. Cool season crops such as radish, carrots, lettuce, spinach, broccoli, cauliflower, kohlrabi, asparagus, potatoes and peas can be planted from late March through the end of April when soil temperatures have reached a minimum of 40-45 degrees Fahrenheit.
Freezing temperatures and frost can always occur through April. Even cool-season crops don’t grow well in these temperatures. If you have a spring garden growing with a frost or freeze event predicted, place a floating row cover or a sheet over the plants to prior to the cold temperatures to protect them from damage. If the cold will be a problem for multiple nights in a row, remove the row cover or sheet during the day once it has warmed up and replace it at night.
Cold Temperature Injury
If your spring crops are planted too early and cold temperatures return, they could be injured. Cold injury on plants will appear as black or dead leaves, water-soaked spots on the leaves, wilting, discoloration, or death.
Most cool season crops can withstand a frost of 31-33 degrees. Temperatures from 26-31 degrees may burn the foliage on broccoli, cabbage, cauliflower, lettuce, onion, radish, and turnips. These temperatures will likely not kill the plants, but that depends on other factors such as growth stage and temperatures the plant has faced prior to the freeze. If the temperature suddenly drops to the freezing level when it has been warm, that can cause death. While plants growing in consistently cool weather with a drop lower into the freezing level are more likely to survive. Brussels sprouts, carrots, kale, and spinach can survive temperatures even lower than 26, for the most part. (According to Texas A&M Extension)
Summer Crops
Wait until after the frost-free date to plant warm season crops so they aren’t harmed by a late frost. The average frost-free date for southeast Nebraska is April 29-May 12, but this is an average guideline. I like to wait until Mother’s Day weekend to plant my summer crops to avoid the late frost we frequently have.
Warm season vegetables for Nebraska include tomatoes, peppers, eggplant, cucumbers, zucchini, peas, beans, corn, watermelons, cantaloupe, pumpkins, gourds, squash, okra, and sweet potatoes.
Care of the Garden
Make sure that the soil is dry before you work in or plant your garden to avoid soil compaction. Locate your garden where it will receive at least 6 hours of sunlight per day, but 8-10 hours of sunlight is best. Make sure that it is planted on level ground to ensure uniform watering. Gardens need about 1 inch of water per week. Soaker hoses and drip irrigation are the best options to reduce diseases, but overhead irrigation can be used. If watering overhead with sprinklers, water early in the day, to allow the garden enough time for leaves to dry out before nightfall.
Vegetable gardens should be mulched to manage weeds. Grass clippings make a good mulch as long as the lawn hasn’t been treated with any herbicides this season. If grass isn’t available, use straw, newspaper, soybean or wood chip mulch.
If you have any further questions please contact Nicole Stoner at (402) 223-1384, nstoner2@unl.edu, visit the Gage County Extension website at www.gage.unl.edu, or like my facebook page at http://www.facebook.com/NicoleStonerHorticulture and follow me on twitter @Nikki_Stoner
Nicole Stoner
Extension Educator
Gage County
April 2024