Your midsummer yard and garden to-do list – InForum

FARGO — How can you tell whether a plant you don’t recognize is a weed or the new perennial you installed last year? It’s easy; just give the plant a little pull. If it pops out easily, it was the new perennial. If it remains sturdily in place, it’s a weed.

Weeding is one of many projects around yard and garden in midsummer. The following is a to-do list for the coming weeks.

  • Annual flowers in pots, planters, hanging baskets and flower beds are approaching the peak season. To keep them prolific until frost, fertilize at least every two weeks with a water-soluble type, even if the potting mix contains slow-release fertilizer.

    Flowers in containers continue blooming stronger if fertilized regularly.

    Michael Vosburg / The Forum

  • Geraniums continue blooming best and appear neater if withered blossoms are removed. Instead of cutting, snap them off at the natural joint where the flower stem is attached to the plant.
  • Some annual flowers continue blooming longer if the withered flowers are removed before seed pods form, including marigold, daisy, snapdragon, salvia and zinnia.
  • Prune off the spent flower stalks of iris and peony before seed pods enlarge, so plants don’t divert energy unnecessarily to seed production.
  • Shrub roses bloom heavily in June. Many types will produce additional flushes of flowers if the withered flowers or clusters are removed. Prune down to just above a leaf containing five or seven leaflets for the strongest rebloom.
  • Clematis bloom best if kept well-watered. As the old saying goes, they like their head in the sun and their feet in the shade. Keep the root system cool by mulching with shredded wood products.
  • Blossom end rot of tomatoes is a perpetual problem for many gardeners, especially with the earliest fruits. For best prevention, keep the soil evenly moist by mulching around plants with straw or grass clippings that are herbicide-free. Soil that’s evenly moist allows tomato roots to access soil calcium, which is usually plentiful but inaccessible if soil fluctuates between dry and moist.
  • Hill up soil around potato plants to prevent shallow tubers from turning green, which is caused by exposure to light.

    Remove spent blossoms from geraniums by snapping away the flower stem from the point of attachment.

    Michael Vosburg / The Forum

  • Potato plants can be decimated by Colorado potato beetles, both the round striped adult beetles and the red-orange larvae. Pick by hand and drop in a bucket of soapy water, or use the insecticide spinosad. Most other insecticides have become ineffective against the pest.
  • Be on the lookout for white cabbage butterflies that lay eggs that hatch into green cabbage looper worms. Treat cabbage, cauliflower, broccoli and kohlrabi with the organic insecticide BT when worms are newly hatched, and Sevin or Eight if worms are more advanced.
  • Continue spraying apple trees for apple maggot control every seven to 10 days until mid-August.
  • Be diligent with weed control in garden and flower bed. Removing all weeds before they produce seed is an investment in future weed-free gardening, or at least a noticeable reduction. One escaped weed can produce hundreds or thousands of seed, and such seed usually remains viable to plague gardens for decades to come.
  • Lawn weed control is usually best delayed until early September. In midsummer, weeds become tougher and more difficult to kill, and herbicides can damage lawns when applied in periods of heat and reduced moisture.
  • Rhubarb harvest is best discontinued now, to allow plants to replenish stored energy. After the plant has rested a month or two, harvesting a few stalks in late summer for a pie or two is usually fine.
  • Allow the fernlike tops of asparagus to grow and flourish, which aids next spring’s crop.
  • Remove sucker sprouts from around the trunk at the base of linden, apple, ornamental crabapple, Japanese tree lilac, Canada red cherry and other trees. Prune as flush as possible.
  • Dry weather followed by a soaking rain is the main cause of cracking of carrots and tomatoes. Apply several inches of mulch to keep soil more consistently moist.
  • Perennial flowers, trees, shrubs and roses can be planted all summer. Water deeply immediately after planting and then once or twice per week, depending on weather. Brush aside the surface, and if moisture is visible, don’t water. Above all, don’t drown new plants with daily watering.
  • Take time to sit, relax and enjoy the sights and sounds of the yard, garden and landscape.

Don Kinzler, a lifelong gardener, is the horticulturist with North Dakota State University Extension for Cass County. Readers can reach him at [email protected]