Plant of the week

Tuberous Begonia. Begonia tuberhybrida. (Christine McComas, Baltimore Sun / April 11, 2012)

When do I put down grub killer in the spring?

Spring grubs are big, but they are barely eating now and not damaging your lawn. Don't waste your money on these grubs.

Also, applying grub killer in spring sickens wasps that are predators of grubs. You've probably seen these beneficial wasps hovering over your lawn, looking for grubs to attack. Natural controls usually keep grub populations under control. A few grubs are normal and keep the predators around.

Rarely is lawn damage caused by grubs. If your lawn has dead patches that roll up like a carpet in late summer/fall, with over a dozen grubs per square foot, then, yes, grub control is called for the next year in early summer. You want it in the soil when grubs are small. They start hatching in July.

What native shrubs work as foundation plants — evergreen or flowering? I don't want anything too wild-looking.

Match your choices to the available sunlight, soil type and moisture levels. Evergreens in low to medium heights include inkberry, mountain laurel, American arborvitae and several junipers. Low- and medium-height flowering shrubs include many gems such as summersweet (clethra), Virginia sweetspire, native azalea species (fragrant!), button bush, red chokeberry, ninebark, Annabelle hydrangea, highbush blueberry (yum!) and Viburnum nudum.

University of Maryland Extension's Home and Garden Information Center offers free gardening and pest information. Call 800-342-2507 or send a question to the website at hgic.umd.edu.



Plant of the week



Tuberous Begonia



Begonia tuberhybrida

Admit it. We all have plants that tempt us. (You're "just looking" in a greenhouse or nursery but can't help bringing home a lovely new specimen.) One plant in this category is the tuberous begonia. After a long, dull winter, they shout out with lush flowers and foliage in strikingly bright, clear colors. Tuberous begonias are frost-sensitive plants grown from tubers. They need bright light but no direct sun. Upright forms are perfect for pots. When placed in evenly moist, well-drained soil and fertilized monthly, they bloom happily all summer long. Two different flower forms occur on each plant: double flowers are male, and single flowers are female. Tuberous begonias have thick, succulent stems that need support as they grow. Use a stake and tie toward the outer side of the pot to protect the tuber. At the end of the season, toss or overwinter in a greenhouse.

— Christine McComas