When gardening space is at a premium.
For those of us with urban gardens, it is possible to run out of gardening space making the area between the sidewalk and street a space of opportunity. Even though the summer heat is on, this is a great time to think about it. Soil in these areas is often very compacted and of very poor quality. This is the time to cover an area with cardboard or newspaper and compost or mulch to smother weeds and create better soil conditions for new plantings in fall. Just a quick note: not all jurisdictions allow homeowners to plant in this area, so best to check first.
Your choice of plants for this location is critical. Whether in shade or sun, tough plants are needed as the area is often subjected to foot, pet and even bike traffic. Here are some ideas for this tricky space.
For shady spots, Pennsylvania sedge (Carex pensylvanica) is said to be a tough ground cover that grows well even beneath mature street trees. Last year, I decided to give it a try in front of our house which has street parking, a very active sidewalk with dogs, including our own furry friends, and no irrigation.
After covering the soil with cardboard and mulch for several months, these plugs were planted beneath a very old red oak tree in the spring of 2020. I weeded twice last summer. More frequent weeding would have made that weeding far more manageable and would have also decreased competition for the plugs. Despite best intentions, I watered only sporadically.
In early 2021, another major weeding was needed. The plants on the east side get full shade and are larger. which makes sense given that this sedge is best suited for shade. The bare spot where plants did not survive is a favorite pet area. Eventually, the idea would be for the sedge to form a carpet. Once that happens, I will likely have to replace a few plants from time to time but the need for weeding should be far less. This project is definitely a study in patience though!
My goal is to achieve something like this tree lawn planting of a variegated, non-native carex. Using the rock near the street edge, a particularly highly trafficked area, is a great idea from both a garden maintenance and car passenger standpoint.
Another plant to try might be coral bells (Heuchera americana). These 'frosted violet' coral bells, a cultivar of the native, planted as plugs two years ago are thriving in their third year and seem to be able to take the dry, shady conditions fairly well. They were also planted after covering the area for several months with cardboard and mulch. They may not be the best choice for areas where people need to get in and out of cars though.
The straight species of the native coral bells are Heuchera americana and Heuchera villosa, the latter native to the southeast. Most of us have been dazzled by the incredible array of cultivars of coral bells at nurseries. There are so many out there. This report by Mt. Cuba ranks coral bells in terms of performance in heat, humidity and sun in case you are curious.
The widely available cultivar Heuchera 'Autumn Bride' also does well in our shady tree lawn. The white flower spikes in August, swaying in a light breeze, are awesome. Heuchera emerges very early in spring and lasts through late fall, and often into winter. Along the way, the three foot high and wide mounding plant provides springy lime green color early in the season which morphs to a slightly darker green in summer. In late July, wand like white flowers emerge and last into September.
This year, I am trying golden ragwort (Packera aurea) in another tree lawn area since it is shade tolerant. This plant is a strong self spreader, particularly in moist soils, and blooms in shade with small gold flowers in late spring. I transplanted it from a moist area where it was spreading too quickly. In many situations, this would be a good thing but in our smaller urban garden, it could take over the other summer blooming perennials. Because the bloom stalks in late spring are a couple of feet high, I planted it on the sidewalk side and will leave the street side mulched to make it easier for people to get in and out of their cars.
Have you had success with other plants in the shade of the tree lawn? Please share in the comments below. Have a sunny tree lawn? Check out this post.
Happy gardening and stay cool out there!