March means spring is here and there is so much to share! This is the month to prune the fruit trees, brambles, summer-flowering shrubs, and to finish pruning the roses.
Rose bushes should be cut back 2/3rds, but climbing roses need to be pruned differently. Remove only the dead, diseased, or crossing rose canes from a climbing rose. Different from shrub roses, climbing roses bloom on the previous year’s growth, so do not prune canes randomly.
Speaking of pruning, March is typically the month during which the temperature remains above 55 degrees. This temperature signals the time to cut back the garden perennials and ornamental grasses because most insects have emerged from dormancy. Cutting back the garden earlier will greatly reduce beneficials and pollinators from the landscape as the old growth is removed.
Avoid pruning spring-flowering shrubs such as Duetzia, Azalea, Viburnums, Ninebark, and Lilac until after they bloom to prevent cutting off the flower buds formed last summer. Fertilize these plants after they bloom, too.
Now is also the time to prune summer flowering shrubs such as such as Butterfly bush, Hibiscus, Weigelia, Beautyberry, Hydrangeas that bloom on old growth, and Rose of Sharon to promote new growth and more blossoms in the summer. Fertilize the summer-blooming shrubs now as noted on the soil test results. Still haven't sent off those soil samples for testing? Do your best to do so now, then follow the directions on the report from the lab. Let’s work together to Save the Bay by fertilizing only when needed! For more information on soil testing: https://www.soiltest.vt.edu/fees-and-forms.html
Dividing and planting perennials is fun to do in March after the ground thaws. I enjoy sharing extra plant divisions with friends and family, too. While I promote planting trees and shrubs in the fall, March is another time to plant them as well. Mulching them well will aid in conserving soil moisture during the upcoming summer months.
As the spring-flowering bulbs bloom, begin a photo journal by taking a photo a week. While you're at it, photograph your landscape, too, so you can record the color sequence and learn where the gaps are. Come fall, the photos will be excellent tools to use to evaluate your gardens.
In the vegetable garden, zones 6b-7b should be planting cool season vegetables in March. I start successively planting garden peas in early March and around late March Virginia Tech recommends sowing the following in the garden: beets, broccoli, cabbage, carrots, chard, kale, kohlrabi, leeks, lettuce, mustard, onions, potatoes, radish, spinach, and turnips.
Mid-March is the time to sow indoors the seeds of tomatoes and peppers to transplant into the garden once the soil has warmed in early May. Per the seed packets, start these plants 6-8 weeks before planting in the garden. Resist the temptation to start them earlier because the plants become very leggy as stem and leaf petiole cells elongate in the lower indoor light.
Steps to reduce stem and petiole elongation in seedlings grown indoors include:
- placing the plants in a south facing window or in a growth chamber with LED lights
- providing 1.5”- 2” of space between each plant
- rotating the plants daily
- allowing the plants to dry out between waterings without wilting
- fertilizing with a half strength dilution rate after the first true leaves emerge
- gently brushing the plants 10 times a day or more
Yes, years ago Cornell University and the University of Georgia proved brushing the young seedlings enough for them to bend without breaking reduces stem elongation! The tool used to brush the young plants must not damage the leaves — a smooth rod meets these criteria. To reduce disease, brush only when the leaves are dry. The frequency of seedling brushing increases the plant response, with 10 times a day being the minimum for the best results. Many commercial growers are recognizing the benefits of brushing, and some are installing mechanical plant brushing equipment in their greenhouses.
Finally, I want to share my shoe box method of plant record keeping. I admit record keeping is a task I must steel myself to keep up to date with at Maymont. It is vital for proper living collections management, and I do not discount the importance of this activity. However, at home I take a minimalist approach that has served me well for years, Peggy’s Shoe Box Method.
With weather history at our fingertips online, I track what I plant in a shoebox rather than a journal. On the plant labels and seed packets, I note the planting date and where it is planted. I then place the seed packet or label in my shoe box where it resides until I move the plant or remove the plant. Upon removal, I make a quick note on the label or packet about the plant and date it. The bedding plant seed packets are bundled by the year for quick reference. Labels from plants that either died or were eaten by the deer are also noted and bundled as well. All bundles are in the shoe box, leaving the tags to plants growing in the landscape loose in the box. While all sketches and designs are properly stored in the garden folder, my garden shoe box is on the shelf by the pruners, right within reach. This is a simple system that works for me, maybe this system will work for you, too.
Happy Gardening,
- Peggy, Director of Park Operations and Horticulture at Maymont