University of Maryland Extension

May Tips & Tasks

May Tips & Tasks

blooming rhododendron


Outdoor Yard and Garden Tips 

  • If your azaleas, rhododendrons and other spring flowering shrubs are growing too large prune them after they bloom.

  • Thin out interior boxwood branches to improve air circulation and reduce disease problems such as volutella canker. Also, look out for boxwood blight.

     

  • Older leaves of holly and magnolia may begin to yellow and drop. This is a natural process of regeneration and does not indicate a problem with the trees.

  • Lace bug feeding may be seen on rhododendrons, azaleas, andromeda (Pieris japonica), and mountain laurel. Look for small white or yellow spots on the upper sides of leaves. On the underside of leaves, you may notice small black fecal spots, nymphs, and adults. Damage on new growth indicates overwintering eggs have hatched and the new generation has started to feed. There are multiple generations per growing season.  Lace bugs are more of a problem on stressed plants growing on exposed, hot, and sunny sites.

  • Rose Rosette, a relatively new disease of roses caused by a systemic virus and  spread by small eriophyid mites, can kill landscape roses. Including the more disease resistant roses such as the Knockout cultivars. 

  • Summer annual bulbs like gladiolus, tuberous begonias, cannas, caladium, and dahlias can be planted now.

  • Attract pollinators and natural enemies to your landscape by planting a wide variety of flowering annuals and perennials, including native plants that will bloom over the entire growing season.

preparing vegetable bed

  • Begin setting out transplants of warm season crops like squash, pepper, eggplant, and tomato. There is still a small possibility of late frosts. Be prepared to cover plants with a tarp or light blanket if frost is expected.

  • Pinch the blooms from flower and vegetable transplants before you set them out. This will help direct the plants’ energies to root development and will result in more productive plants. Gently break up the roots of root-bound transplants before planting. 

  • Did your garden get overtaken by weeds last year? Start spreading mulch around plants and between rows. Use dried grass clippings, leaves collected from last fall, sections of newspaper covered with straw, black landscape fabric.

  • Cover strawberry plants with bird netting, tulle (found in fabric stores), or floating row cover before the berries become ripe to exclude birds, squirrels, and other hungry critters.

  • Leave grass clippings where they lay. Grasscycling eliminates bagging labor and costs, adds organic matter and nitrogen to your soil and does not contribute to thatch build-up.

  • Carpenter bees cause concern at this time of year. They make clean, round holes about a ½ inch in diameter but usually will not bother wood that is freshly painted or stained. 
    carpenter bee and stain on siding
    Carpenter bee and staining

  • Ticks are active when the temperature is above freezing. Wear light-colored clothing and get in the habit of checking yourself, your loved ones, and pets closely for ticks after spending time outdoors. Repellents are also an effective tool to keep ticks away.

Indoor Plant and Insect Tips

  • Move houseplants outdoors after the danger of frost has passed. To avoid sunscald first place them in a shady location and over a period of two weeks or so gradually introduce them to more sunlight.

  • Fleas are sometimes observed in homes where there are no pets. The most likely source is a wild animal such as a raccoon living in the attic, crawl space, chimney or some other sheltered area connected to the inside of the home. If you have pets that have a flea problem, contact your veterinarian for the safest and most effective flea control products.

  • Clover mites are usually most noticeable in the spring when temperatures are between 45° and 80°F and the humidity is high. On warm days they cross the grass and crawl up the sunny sides of buildings and will possibly enter into homes. 

Maintained by the IET Department of the College of Agriculture and Natural Resources. © 2020. Web Accessibility

University programs, activities, and facilities are available to all without regard to race, color, sex, gender identity or expression, sexual orientation, marital status, age, national origin, political affiliation, physical or mental disability, religion, protected veteran status, genetic information, personal appearance, or any other legally protected class. If you need a reasonable accommodation to participate in any event or activity, please contact your local University of Maryland Extension Office.