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Ask the Gardener: Great plants for streetside strips

Ask the Expert Gardening
Black-eyed Susans, or rudbeckia hirta, are the longest-blooming perennials and look beautiful on a garden strip between the street and lawn.
Black-eyed Susans, or rudbeckia hirta, are the longest-blooming perennials and look beautiful on a garden strip between the street and lawn. Adobe Stock

What to do this week Thicken lawns by patching and overseeding with a seed mix dated this year and containing at least 50 percent total bluegrass and fescue. Buy a shade formula for areas that get less than six hours of direct sunlight. Rent a spreader for even distribution, and rake in the seeds so they are thinly covered with soil. Then keep them moist until they sprout. Tomatoes are leggy this year because of early rains, so pinch them back to hasten ripening fruit. Plant seeds of spinach, arugula, radish, and mache. Try spraying dishwasher soap mixed with water on sucking insects like aphids. Handpick caterpillars and beetles from vegetables and drop them into soapy water. Dot the garden with pots of cushion mums you buy just as they begin to open. Don’t bother to plant them. Instead, just compost them after flowering, as they seldom winter here.

 

Q. What can I plant along the narrow area between the street and the sidewalk (sometimes called the “hell strip’’) that won’t look gangly? I am a fan of entomologist Doug Tallamy and want to feature native plants that help wildlife.

T.T.T., Newton

A. This is the best time of year to plant. I usually combine perennials with bulbs. “Hell strip’’ plants should be short, aggressive enough to keep out weeds, and drought-resistant so you don’t need to water. Silver Mound (artemisia schmidtiana) looks like a silvery cushion in sunny locations, perhaps mixed with a few different sedums, such as Autumn Joy (Hylotelephium ‘Herbstfreude’) and mounding Pennisetum. These also combine well with native black-eyed Susan (rudbeckia hirta), the longest-blooming perennial, and bright orange asclepias milkweed, a native favorite of pollinators. You could also try just one kind of plant instead of a mix. Lily-of-the-valley is a thug but could substitute for grass in a shady area. Siberian iris is another tough flowering perennial for sun or shade, and it is neater than daylilies. I would also stick in bulbs of March-blooming crocuses and yellow April daffodils this fall because they are such a low-maintenance way to extend the show. Before you plant, remove all grass and weed roots. That’s the hard part. Set the plants where you want them, then fill the spaces in between with weed-free compost. Finish off with a layer of mulch to keep the moisture in and the weeds out, then water deeply to knit everything together.

Q. My husband and I just bought our first home. We’d like to replace a portion of the lawn with a native plant garden. How should we remove the turf from this area? We’ve tried to remove the grass with a shovel, but the work is very slow and exhausting

E.P., Sharon

A. Removing sod is back-breaking work in dry soil, so be sure you mow and water a day or two before. You also need the right tools. A manual sod cutter or a flat-edged shovel and the blade end of a mattock are tools for pulling up strips of sod by hand for small and hard-to-reach areas. But for sizable projects, rent a motorized sod cutter from a hardware store. It’s important to remove old turf because a rototiller will not break it up. Take your yard all the way down to an inch below the bottom of the grass roots. Don’t cut too shallow, or the grass may resprout. For proper drainage, you will want the finished garden to lie 1 inch below adjacent paved surfaces. Make a test cut first to help you adjust your sod cutter’s settings, and then cut the sod into 3-foot-square sections for composting or moving to another area where you want the grass. Cover the excavated area with plastic tarps immediately so weed seeds don’t blow in and undo your efforts.

A physically easier alternative is simply to layer an inch of compost over the lawn and cover it with water-permeable horticultural plastic to smother the grass. Hide the plastic under a layer of bark mulch. When you want to plant something, just pull back a square foot of mulch, cut an “X’’ through the plastic, dig a hole, insert the root ball of your new plant, and water it. Then pull the plastic and mulch back around it.

A third and much more effortful method is called “double digging.’’ Mow, water, and dig the top 8 inches of soil, including all the grass roots, onto a tarp. Then dig up the second 8 inches of rootless subsoil and put that in a different pile. You will have a 16-inch-deep hole. Then you layer the turf into the bottom of the hole, grass side down so it can’t resprout. It will rot in place, adding its biomass to the soil on a deep layer. Then fill in the top of the hole with your pile of subsoil, amended with compost. You end up making a bed that is loose, rich, and deep. Because this technique is so much work, most people confine it to creating vegetable beds of modest size, though I have used it for growing ornamentals that are heavy feeders such as delphiniums with spectacular results.

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