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Ask the Gardener: Plant ideas for those tricky shady or sandy spots

Ask the Expert Gardening
Adobe-Stock-Purple-Heuchera
Heuchera is a colorful perennial that grows in shady spots. Adobe Stock

What to do this week Water early in the morning or late at night to reduce evaporation. Remove weeds before they go to seed and put them in the trash, not the compost bin. The art of weeding is learning to tell the really bad weeds from the no-big-deal weeds. Prioritize. I patrol my yard for the few very bad weeds and remove them immediately before they get a foothold. Noxious weed roots are persistent and can take years to remove when established. I just discovered a swallow-wort vine laden with seeds in my orchard in the same spot where I killed it 10 years ago. I immediately clipped and bagged it and sprayed the remaining bottom leaves and stems with glyphosate in hope of root kill. Then I cut back the desirable plants it was hiding in so I can keep an eye on that spot.

Swallow-wort is a 3-foot vine with dark, shiny, pointed leaves and tiny black star-shaped flowers. It poisons monarch butterflies, which mistake it for milkweed. Visit invasive.org for photos of the worst weeds. Check the vine section for bittersweet, porcelain berry, and the aptly named mile-a-minute vine.

TIP Anytime you find an unknown vine, just pull it out. Don’t be lured by curiosity into letting it bloom first to see what it is. Nice vines are something you fall in love with and buy in a nice nursery. Bad vines show up uninvited, like bill collectors and home invaders.

Q. I have mostly shade with some areas of half-day sun. Are there flowering perennials for these areas? I would love some color.

J.B.R., Natick

A. Most perennials for shade are white and bloom in early spring for only a couple of weeks before the trees leaf out. You could try Epimedium, bleeding heart, hellebore, and minor early bulbs such as chionodoxa. Bright-red perennial lobelia cardinalis and astilbe are summer wetland flowers that require extra water. Oriental lilies and garden phlox survive light shade. The common orange tawny daylily blooms pretty well in shade, unlike hybrid daylilies. But your best bet is annuals such as begonias and impatiens. Also consider colored foliage plants such as perennial heuchera and hosta or annual coleus.

 

Q. We have a plot of land bordering Quincy Bay. We have tried growing grass there. It will last a year or so then die. Is there a better groundcover given the saltwater and windy conditions that you can walk on?

J.A.M., Quincy

A. You are going to have to experiment. I would go to an established local nursery in a seaside community and ask what they sell for this problem. Then I would buy just a few each of several different ground covers, because the successes will spread. If different types survive, they will create a tapestry effect. Or maybe there will be one winner that takes it all. Let the conditions dictate what happens, because nature is stronger than you are. There are many plants for dry sand, but it is asking a lot of a plant to survive at the shore while being walked on. But you could try a mail-order company called Stepables (stepables.com) that sells short, drought-resistant sedums, thymes, and dianthus.

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