Here is What to Do the Week of May 1

By Ron Kujawski

* Stop by your local garden center and buy some pansies to give to Mom for Mother’s Day … May 12, in case you’ve forgotten. She can plant them in patio pots, window boxes or in the garden for a splash of color. The plants are tough, like Mom, and love cool spring weather. The flowers are edible, so she can mix them into salads or decorate cakes and cupcakes.

* Begin harvesting asparagus spears when they are about eight inches tall. Some gardeners say that the spears should be snapped off at ground level, others say they should be cut off at or just below ground level. I say: Take your pick, it doesn’t matter. Asparagus is a very perishable crop, so immediately store harvested spears in the refrigerator. Wrapping a damp paper towel around the base of the spears will help keep the spears turgid.

* Start an asparagus bed if you do not have one. Prior to planting, work in limestone or wood ash, compost or aged manure, and a phosphorus fertilizer to a depth of at least eight inches. Dig a trench that is six to eight inches deep and about a foot wide. Place the crowns into the trench, spacing them a foot apart. Cover the crowns with two inches of soil. As the plants grow, gradually fill in the trench, a few inches at a time, until the soil level is just a little higher than the surrounding soil. Don’t harvest any spears until next year or the year after.

* Harvest rhubarb by grabbing the leaf stalk at its base and pulling it down. Discard the leaf blades as they contain toxic levels of oxalic acid. I’ve read that planting rhubarb around the edge of a garden will keep rabbits out. Lucky for Peter Rabbit Mr. McGregor didn’t know that.

* Make a second sowing, or first, of spinach, mesclun and other leafy greens. Also, set out transplants of onions, cabbage, broccoli, and cauliflower. Given the fierce winds at times this spring, it would be worthwhile to place row covers or hot caps over the transplants as protection.

* Examine emerging perennials for signs they need to be divided. Usually, such signs read “Divide me!” Otherwise, look for thinning or dead areas at the center of the plant. If it was apparent last year that plants had lost some of their vigor, as shown by decreased size of foliage and a reduction in the number and size of flowers, divide them, preferably on a cloudy day.

* Start checking for spider mites on spruce, arborvitae, juniper, hemlock, pine, Douglas-fir, and balsam fir. Spider mites feed by sucking sap from the needles of these trees, leaving tiny yellow spots or stippling on the needles. Eventually, the foliage looks bleached or bronze in color. A quick check for spider mites can be done by placing a sheet of white paper beneath a branch and then striking the branch with a ruler (reminds me of my school days). Tiny dots, about the size of the period at the end of this sentence, slowly moving across the paper indicate the presence of mites; either that or you need to visit an optometrist. Control the mites by applying insecticidal soap or horticultural oil according to label directions. An occasional blast of water from a garden hose onto the tree will help keep the population of mites low. Of course, none of these measures can be done easily on tall trees. For those, you may have to hire an arborist.

Ron Kujawski began gardening at an early age on his family's onion farm in upstate New York. Although now retired, he spent most of his career teaching at the UMass Extension Service. He serves on Berkshire Botanical Garden’s Horticulture Advisory Committee. His book, Week-by-Week Vegetable Gardener’s Handbook, is available here.