by Kathy Sykes
In previous Forest Hills Connection articles, I’ve urged you to leave the fall leaves for wildlife spending their winters here and soil care, and retire those leaf blowers for the protection of pollinators and the topsoil. If you’ve taken my advice, here are the next steps for nurturing a beautiful and eco-friendly spring yard and garden.
When to remove the leaf cover from your garden beds
If you’re tempted by the recent warmup to clear out your flower beds in preparation for planting – don’t. Make some tea, relax, and give it a few more weeks. Many of the insects that spent the winter here are still resting snugly in their leaf beds, or need the cover at night if they are emerging during the day. And, while it’s been warmer, a surprise frost could still damage or kill anything planted too early. (DC’s last freeze can arrive anywhere between late March and mid-April.) So leave the leaves, dead or dormant plants and other natural litter alone until nighttime temperatures are consistently above 50 degrees Fahrenheit.
The 70 percent rule for planning your plantings
Native plants are critical habitats for our native pollinators, as they have evolved together over millennia. So, one way to make a positive impact for all living things is to try to have 70 percent of the plants in your yard or planters be native ones.
Keystone plants, native “super performers” as described by author and entomologist Doug Tallamy, host many more bees, butterflies and moths than other native plants. In our area, these include goldenrod, asters, strawberry plants (great for groundcover), sunflowers, Joe Pye weed (which is not a weed), black-eyed Susans, violets (another ground cover) and hibiscus (also known as rose mallow).
Milkweed is not a keystone plant, but it is important to the caterpillars that transform into monarch butterflies.
And again, mid-April is latest we could see a late frost, so you may want to wait until later in April to plant native seeds.
Remove invasive plants
Invasive species hurt biodiversity in many ways. They spread aggressively, outcompeting native plants for food, water, sunlight and space. Some emit chemical toxins that inhibit the growth of the natives, or kill them. Some also confuse and poison native wildlife.
For example, the West Virginia white butterfly and the falcate orange-tip butterfly lay their eggs on a native early spring wildflower, the toothwort. Garlic mustard, a non-native toothwort cousin, is similar enough in chemistry to confuse the butterflies into laying their eggs on the invasive plant instead. But unlike the toothwort, garlic mustard poisons the caterpillars that hatch from the eggs. As a result, we lose a generation of these native and less common butterflies.
Anytime is a great time to remove invasive plants such as garlic mustard, English ivy, burning bush, porcelain berry, and bush honeysuckle from our gardens and landscapes. This is a good guide to invasive plants in our area.
Avoid March mulch madness
Mulch has a place in our gardens when used properly. A layer of mulch can conserve soil moisture, moderate soil temperature, suppress weed growth, reduce soil compaction, and improve aesthetics. However, it is often used inappropriately. I have seen mulch used in place of groundcover or adding more plants to a landscape. And, too much mulch is harmful to gardens.
Excessive amounts of mulch – more than three inches – will suppress not only weeds but also spring bulbs and other perennial flowering plants. It can also suffocate plants and keep water and oxygen from reaching the roots. Trees are harmed when mulch touches the bark, causing bark rot. And when piled so high around a tree that it takes the form of a volcano, mulch can cause root flare, where the main roots attach to the trunk.
I prefer to plant densely and create a natural mulch with leaves. This method also conserves moisture, suppresses weed growth and retains the topsoil in heavy rain.
Prune with care
Pruning involves removing the undesirable, diseased, or dead parts of woody perennials such as trees and shrubs. The process also can enhance air circulation and stimulate new growth.
Winter is often a good time to prune, since most trees and shrubs are dormant and it’s easier to see what you’re doing. However, one can remove dead or broken branches any time of the year. Just be sure that you’re not destroying someone’s home.
Many moth and butterfly species spend the winter dangling from branches in delicate cocoons. So, keep an eye out for branches with a cocoon or chrysalis, and avoid pruning them until later in the spring season, when they emerge.
By taking these steps, you’ll be doing a good thing for pollinators, which are both critical to the survival of humans, and endangered by our actions. According to a 2019 United Nations report on biodiversity, one million animal and plant species face extinction due primarily to habitat loss and intensive agriculture. Other causes of insect decline are climate change, chemical pollutants, and invasive species.
However, each of us can make a difference where we live, and advocate for a better environment for all living things: plants, insects, and humans. Just as doctors take the Hippocratic oath, gardeners should also pledge to do no harm, and better yet, do some good.
Kathy Sykes is a certified Master Gardener and Master Naturalist. She is often seen tending treebox pollinator gardens up and down Connecticut Avenue for Van Ness Main Street, and guiding volunteers in the effort. Speaking of which:
Kathy is leading plantings the first three Saturdays in April, and the first three Saturdays and Sundays in May, from 1 to 3 p.m. To sign up, email email@example.com with the date(s) and number of people.
April 1: Franklin Montessori School block – 4473 Connecticut Avenue
April 8: Viet Chopsticks block – 4304 Connecticut
April 15: Forest Hills DC Senior Living block – 4901 Connecticut
May 6: Politics and Prose block – 5015 Connecticut
May 7: Calvert Woodley block – 4339 Connecticut
May 13: Franklin Montessori School block – 4473 Connecticut
May 14: Laliguras block – 4221 Connecticut
May 20: Forest Hills DC Senior Living block – 4901 Connecticut
May 21: Viet Chop Sticks block – 4304 Connecticut