bumble bee on a purple coneflower
Updated: December 21, 2023

Outdoor yard and garden tips

Sustainable Gardening

  • Take part in Pollinator Week! This is an annual celebration of the importance of pollinators and the many ways we can support them in our gardens and landscapes. 
  • Reduce and compost food and yard waste. About one-third of all food produced never gets eaten. Food waste dumped in landfills generates climate-warming gasses as it decomposes without oxygen. Making compost at home is a solution.
  • Weeds are easier to manage when they are young and small and the soil is slightly moist. Hand-pull weeds or use other methods to manage weeds without chemicals.

Trees & Shrubs

  • Water newly planted trees and shrubs until they become established (for about 2 years), especially in the summer and fall. Water deeply by allowing the water to soak into the soil directly underneath and around the root ball.  Check the depth of water penetration into the soil by digging a small hole after watering. It should be moist about 6 inches down. A 2-3 inch layer of mulch is helpful. Keep mulch away from the trunk or stem.

Edible plants

  • Perpetual spinach, Malabar spinach, amaranth, sweet potato leaves, 'Vitamin Green', 'Tokyo Bekana’, and Swiss chard are good heat tolerant salad greens for Maryland.
  • Flea beetles are a serious pest of eggplant and also affect potato, tomato, and members of the cabbage family. Row covers are an effective means of management but should be removed when plants flower to allow for cross-pollination by bumblebees. Spraying plants with “Surround” (kaolin clay) creates a white particle film that can minimize flea beetle feeding. You can also control flea beetles with “neem”, a botanical insecticide.
  • Young tomato plants may be exhibiting symptoms of various leaf spot diseases such as septoria and early blight. Remove badly infected lower leaves, keep a thick organic mulch around plants and avoid overhead watering.
  • “June drop” of excessive fruits (especially peaches) is a natural thinning phenomenon and is more pronounced where no hand thinning has occurred. Hand thin the fruits on plum, peach, apple, and pear trees, leaving space (the width of one fruit) between the remaining fruits. Disease and insect problems, environmental stress, and lack of pollination or fertilization can also cause fruit drop. Pick up and throw out all dropped fruits.


  • Cut iris flower stalks down to the crown when they are finished blooming. Leave the foliage alone. If your iris are overcrowded after flowering lift and divide them. Check rhizomes for iris borer.
  • Warm-season annual flowers like zinnias, sunflowers, and cosmos can still be started from seeds at this time.


  • Bagworm larvae are hatching out this month and constructing new bags. Look for the little bags moving around on evergreen trees and shrubs and be prepared to spray infested trees with the microbial insecticide, B.t. between now and mid-July. 
  • Cottony camellia scale (Pulvinaria floccifera) feeds on camellia, holly, yew, euonymus, sweetbox, and maple.  It is also reported on beautyberry, jasmine, mulberry, and hydrangea. They lay white cottony ovisacs (egg masses) on the undersides of leaves. If infestations are heavy and sooty mold is objectionable, use a summer rate of horticultural oil (refer to the product label) in June, when beneficial lady beetles go into aestivation (summer dormancy) and the scale crawlers (juveniles) are active and most vulnerable to the spray.
  • Ticks are very active right now. Ticks can carry serious diseases that affect humans and pets. Wear long pants, long sleeves, and close-toed shoes. Tuck pants into socks. Tuck shirts into pants. Use insect repellents (such as DEET), always AFTER putting on sunscreen.  Shower and check for ticks after being outdoors.


  • Apple scab and a number of rust diseases (cedar-apple, cedar-quince, cedar-hawthorn, Japanese apple, and pear trellis rust) are destructive diseases of crabapple in the landscape. They cause severe leaf defoliation by mid-summer if not treated. The best defense is replacing disease-prone cultivars with resistant selections available at garden centers.

Indoor plant and insect tips

Indoor plants

closeup of mealybugs
Photo: Peggy Greb, USDA Agricultural Research Service, Bugwood.org
  • Monitor houseplants kept indoors for mealybugspider mitesaphidswhitefly, and scale. If houseplant pests are a problem consider spraying with a labeled horticultural oil or insecticidal soap. If possible, move the plants outside before spraying and when dry, move them back indoors. Discard heavily infested plants.


  • Pantry pests, like Indian meal moths, grain beetles, cigarette beetles, and carpet beetles may be found around windows trying to get out of your home. These pests can be swept up or vacuumed.  No chemical controls are recommended.