Boxwood beware: How to care for the classic shrub and prepare your spring garden

Though things have settled down since boxwood blight was discovered in 2011, keep your boxwoods well-groomed, with old twigs and debris cleaned out from the center of plants. Photo: Robert Llewellyn Though things have settled down since boxwood blight was discovered in 2011, keep your boxwoods well-groomed, with old twigs and debris cleaned out from the center of plants. Photo: Robert Llewellyn

When it burst upon the scene five years ago, boxwood blight put a big scare into Virginia nurseries and all who love the iconic shrub, though perhaps some who scorn it for its historical associations and acrid smell would just as soon see the genus in its grave. Much like a sci-fi movie, sticky spores attach to anything that’s been in contact with infected plants (pruners, shoes, gloves, old leaves) and pathogens live in the soil for five to six years. The afflicted drop their leaves, decline and die. Labeled a “devastating disease” by the Virginia Cooperative Extension, it wreaked havoc among old English and American varieties before nurseries learned to control it with strict hygiene and reliance on resistant varieties.

Robert Saunders, who grows boxwoods with his brothers just south of Lovingston, says things have settled down since the blight was discovered in 2011. He sees it now as manageable, but “the days of planting large numbers of English boxwood are over.” So, if you have some ancient specimens on grounds—soft fluffy English or burly dark American—now’s the time to protect them. Never prune boxwood in wet weather or subject them to overhead irrigation.

Unlike English and American (Buxus sempervirens), littleleaf boxwood (B. microphylla) produces cultivars apparently highly resistant to the fungus. Green Beauty, Wintergreen and Winter Gem are among the most highly ranked for resistance.

The gist is, if you have extensive old boxwood plantings, do not let people care for them who have tramped through lots of other peoples’ boxwoods until they tell you exactly what precautions they are taking (sterilizing tools, replacing coverings on shoes, etc.). It’s in everybody’s interest to do this.

In the meantime, keep your boxwoods well-groomed, with old twigs and debris cleaned out from the center of plants and do not overmulch. Air circulation and keeping infection out of the area are key. If you want to opt out of the whole drama altogether, consider inkberry and hollies for your deer-resistant evergreen needs.

Boxwood cares aside, spring is upon us, with winter jasmine and snowdrops having fully flowered at the end of January. Garden centers will be ready, with most opening March 1. Our last frost date still hovers around mid-May, so be careful setting out tender annuals unless you’re able to toss frost cloth or sheets over them on the frigid nights we’re bound to get at least through the end of March.

Cool season annuals like pansies, violas and sweet William are good choices for early color until the soil heats up. Buy tomatoes as soon as they go on sale to get a wide selection of varieties, but keep them potted so you can whisk them inside if needed before planting them when the earth has thoroughly warmed in May.

Now is the time to fertilize hollies, azaleas and dogwoods with an acidic product like Holly Tone. Pull back existing mulch, scatter fertilizer and lightly scratch in with a garden claw or rake before replacing the mulch. Boxwoods, however, need very little fertilizer and prefer a slightly alkaline soil, so keep Holly Tone away from them.

Resist the temptation to recarpet all beds with a nice thick layer of fresh shredded hardwood. If you’ve already got 2-3″, rake it up a bit to break the crust and wait until fall to add more. Too much mulch smothers plants and roots, sheds water and invites voles.

Always something to worry about in the garden. Love them or leave them, let us take a lesson in resilience from the boxwoods and welcome spring, ready to deal with whatever challenges nature has in store.

Spring checklist

  • Drop off lawnmower blades, hand pruners and other cutting implements at Martin Hardware for sharpening.
  • Check oil and gas for mowers.
  • Clean and oil hand tools. Sharpen shovel and spade blades with a bastard file.
  • Prune roses and fertilize with compost and well-rotted manure.
  • Fertilize perennials with compost or organic slow-release 5-10-5 product.
  • Top-dress bare spots in the lawn with compost before seeding and strawing.
  • Start indoor seeds—tomatoes, cleomes, zinnias—for setting out in mid-May.
  • Sow cool-weather greens —arugula, cilantro, kale, lettuce, mesclun—outdoors.