Q: When hiking this past autumn I saw a small, short, blue-purple flower that I haven’t been able to identify. Do you recognize it?
A: Indeed, this is a native wildflower called forked bluecurls (Trichostema dichotomum), and it’s a member of the mint family. Found essentially statewide, these low-growing annuals bloom from late summer into early autumn in a beautiful hue of deep blue-violet. They prefer open habitats (not too much tree cover so they receive some dappled sunlight) with dry, sandy, low-fertility soils, such as around rock outcroppings. I see them with regularity around the Potomac River gorge area, and they always bring me joy.
Q: I have a consistently wet part of the yard that surrounds a natural depression that usually contains some water, like a tiny pond. It’s far enough from the house that I can accommodate trees, and I’d like to plant a few in the area for added interest and wildlife value. What types of trees can handle that consistent moisture? Maybe something more out-of-the-ordinary?
A: A few tree species can handle pond-side soil, and using a mix of species would be a great way to boost their value to wildlife while giving the planting a more natural look. Some of these underused selections may be harder to find at nurseries, though, since they’re not among the mainstream go-to species (which is a pity, as they’re all interesting in their own right). If you’re willing to start small, you can probably root cuttings or start seeds from sources on property where you can get permission to harvest.
Below are some suggestions:
- Alder is a birch cousin that can be found in wet areas, and their roots can fix atmospheric nitrogen. More of a large shrub or small tree at around 10 to 20 feet tall, smooth alder (Alnus serrulata) is abundant in Maryland, though a few other species occur in more isolated parts of the state. They can sucker to help prevent erosion, and birds enjoy the conifer-like seed cones.
- Black willow (Salix nigra) is found in every Maryland county and ranks high for wildlife support. While it can be a bit weak-wooded and grows rapidly, it’s easy to rejuvenate if storms cause aesthetic damage, and very easy to propagate from cuttings. A group of specialized native bees relies on willow pollen, which appears very early in spring. Plenty of caterpillars and other insects utilize it as a host plant, and the insect-eating birds will follow.
- Bitternut hickory (Carya cordiformis) is also widespread in Maryland and is the species of hickory (of the seven that grow here) most associated with wet bottomlands. Hickories support the caterpillars of multiple species of moths, and while they’re very tall when mature, their pace of growth is generally slow. Due to a very long taproot on young trees, get them in the ground as small seedlings or saplings so they’re minimally stressed from transplanting.
- Baldcypress (Taxodium distichum) you may be more familiar with since it’s planted in the Coastal Plain and Piedmont more regularly than the above, even though technically it’s not native to counties in Maryland north of Calvert and Dorchester. Their feathery leaflets turn a brilliant coppery-orange in autumn. It hosts a variety of insect species, and like the hickory, the eventually branchless lower trunk that develops with age allows enough light to reach the ground to grow a good range of shrubs and flowering perennials nearby.
- Atlantic white cedar (Chamaecyparis thyoides) is an evergreen that is native in a narrow band along the Coastal Plain from Maine to Florida. (Use the genetics of locally sourced populations where possible so they’re best-adapted to our weather. This may prove challenging since they are quite uncommon in Maryland.) They won’t stay as dense as leyland cypress or Eastern redcedar, but offer their own pleasant multi-season interest.
If you need easier-to-source species as alternatives or supplements, look to swamp white oak (Quercus bicolor), black tupelo (Nyssa sylvatica), sweetbay magnolia (Magnolia virginiana), American sycamore (Platanus occidentalis), American hornbeam (Carpinus caroliniana), and red maple (Acer rubrum).
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Extension” to send questions and photos.