March Tasks in the Vegetable Garden
March in Virginia, the time when vegetable gardeners spring into action. We’re firing up our grow lights indoors and preparing to do some transplanting and seeding in the garden later in the month. We’re alternately teased by warm, sunny days and frustrated by raw, rainy ones. But hopeful, always hopeful, that the good weather is approaching.
This year a particular concern is the wet ground. 2018 was a record rainfall year and a worse than usual year for mold and disease issues. Unfortunately, wet weather continues and the ground really hasn’t been able to dry out. At planting time, wet ground makes effective tilling impossible, increases risk of compaction and damage to soil structure and can cause leaching of key soil nutrients including N, P and K.
Best short term strategy is to exercise patience, monitor soil moisture, and wait until conditions are right to plant. The old test for till-ability is still useful: take a fistful of soil and squeeze it. If it forms a wet sticky ball, it is too wet. Wait until the soil remains crumbly and workable under pressure before prepping the soil.
For longer term help, the universal soil-fixer, adding organic matter, especially fully decomposed compost, will get you to workable conditions sooner. Humus — organic material that has decomposed to the point that its source is no longer recognizable — has better structural qualities than mineral matter and its high cation exchange capacity reduces nutrient loss via leaching. In addition, regularly feeding soil microbes with organic matter will help to fight off soil-borne diseases. To add compost this spring, wait until the soil is ready, then work up to 2 inches into the top 4 to 6 inches of soil. Follow this up with another application in the fall and you will likely be able to get an earlier start next year.
Another concern is the Spotted Lanternfly. If you haven’t heard about it, it is a highly destructive pest that likely arrived here from China a few years ago. First discovered in Pennsylvania, it has been found in Frederick County, VA and is moving south. The chart below from the Cooperative Extension shows its life cycle. An excellent and very thorough article on this pest can be found in the June 2018 Garden Shed. If you see evidence that you suspect is Spotted Lanternfly-related, please report it to the local Cooperative Extension Office.
Enough with the warnings! Let’s get down to some actual gardening. The following list of cool weather crops was compiled from the VCE publication “Vegetable Planting Guide and Recommended Planting Dates” and indicates which vegetables may be safely planted in our area after the middle of March:
For folks who want to start tomato and pepper seeds indoors, the rule of thumb is to start them indoors about 6-8 weeks before the final frost, which in our area is around May 15th (VCE Publication 426-331). That means we should start tomatoes near the end of March. Peppers need an additional 2-3 weeks head start and can be started now.
It’s not too late for a soil test! If you haven’t had a test for a while, or if you’ve had growing problems recently, or if you are significantly modifying your soil, a test makes sense. They are a valuable tool for identifying and preventing problems as well as keeping your soil at optimum fertility and pH levels and are recommended every three years. A soil sampling kit complete with instructions is available at our local Virginia Cooperative Extension Office on 5th Street Extended. Cost for a basic analysis of nutrient availability, pH and amendment recommendations is only $10. For additional information on soil testing, check out VCE PUBLICATION 452-129.
Lettuce is very sensitive to low (acidic) pH levels, so lime should be applied to your lettuce bed if the pH is below 6.0. A soil test can determine the pH level and the need for lime!
Don’t throw away that leaky old garden hose! You can use it to protect yourself and the blades of your pruning saw and other cutting implements during storage. For example, cut a section of the gardening hose to the same length as the saw blade. Cut the hose lengthwise on one side and place it over the saw blade.
If your garden soil crusts after a rain, this may result in poor germination, because young seedlings are too fragile to break though the crust. This problem may be caused by over-tilling the soil. Cover the seeds with ¼ inch of compost or fine mulch matter, which will keep the soil moist and help prevent crusting.
If you are planning a backyard orchard, start by mapping out the site, giving particular attention to air and water drainage. Remember, just like water, cold air flows downhill. Avoid frost pockets — low areas where cold air gathers and the risk of a late freeze can damage buds and fruit production.
We’ve already talked about the ball-and-squeeze test, but soil temperature is another indicator that the time is right for planting. As a general rule, cool season crops — collards, leeks, peas, radish, and spinach — can be planted when the soil reaches a temperature of 45-50ºF, while warm season crops — cucumbers, squash, corn, beans and melons — require a soil temperature above 65º F.
March is a good time to begin a compost pile if you have not done so already. Most garden centers or nurseries sell composting bins. For help in planning your compost pile see our 2016 February feature article on compost in The Garden Shed, or view the VCE Publication 442-005, “Composting Your Organic Kitchen Waste with Worms.”
Not sure what vegetables or specific varieties of vegetables to plant? Check out VCE Publication No. 246-480 “Vegetables Recommended for Virginia,” which provides a comprehensive listing of recommended varieties.
Spring fertilization of fruit trees should occur about 3-4 weeks before active growth begins. Scatter fertilizer evenly under the tree, starting about 2 feet from the trunk and extending just beyond the drip line or end of the furthest branches. A soil test should be performed prior to applying fertilizer. For additional information on fruit trees, visit VCE Publication 426-841, “Tree Fruit in the Garden.”
The optimum time to prune fruit trees is just before they bloom. Pruning allows the tree to direct nutrients to branches that will bear high quality fruit. The object is to remove dead, diseased or damaged wood. Also, remove shoots that are growing straight up or straight down as neither provides for good fruit development. Growth crisscrossing the center of tree should be removed as well. A more open tree allows greater light penetration and air circulation, thereby increasing fruit quality and reduced disease and insect pressure. For additional pruning information, visit VCE Publication 422-025, “Physiology of Pruning Fruit Trees.”
Bramble fruits such as raspberries and blackberries may be planted in mid- to late March. Plant in moist, well-drained soil containing large amounts of humus or organic matter. For weed control, mulch around newly-planted brambles with a hardwood or softwood mulch. For additional information on how to grow bramble fruit, visit VCE Publication 426-840, “Small Fruit in the Home Garden.”
Thanks for stopping by The Garden Shed. We hope to see you again next month.
“Spotted Lanternfly,” Virginia Cooperative Extension Publication ENT-180, http://pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/ENTO/ENTO-180/ENTO-264.pdf
“Vegetable Planting Guide and Recommended Planting Dates,” Va. Coop. Ext. Publication 426-331, http://pubs.ext.vt.edu/426/426-331/426-331.html
“Is it time to plant vegetables? Ask your soil thermometer,” Oregon State University Extension, http://extension.oregonstate.edu/gardening/it-time-plant-vegetables-ask-your-soil-thermometer