Are invasive plants invasive in their native country? I have to tackle the porcelain berry vines growing up my trees. Is fall a good time to do this?
Most alien invasive plants are already aggressive plants before they get here, with many strategies for outcompeting other plants. For example, they may be first to green up in spring, last to go dormant, and have outrageously high seed production and germination rates. But what makes them invasive on U.S. soil is that they have left all their predators and diseases back in the old country. When no insects or birds can digest them and no disease exists here to infect them, nothing stands in their way. Fall is a great time to tackle many invasive plants such as porcelain berry because they will transport herbicide down to their root systems more effectively.
I dug up brown dead patches of my lawn and found an infestation of white grubs. Is it too late to buy a pesticide and treat the lawn?
By now the grubs have done most of the damage they do at this life stage. Soon they will burrow deep into the soil to "hibernate." Next spring they'll come up again, but their feeding is inconsequential before they pupate into adults and fly off to mate and lay eggs. Normally, we don't recommend treating for grubs because true infestations are not the norm. However, the summer after a true infestation is the exception. Young, newly hatched grubs are most susceptible to grub control products. Use a product containing Merit (imidacloprid) or Acelepryn. Apply between mid-May to the Fourth of July.
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
Jack O' Lantern Mushroom
How Halloween can you get? This mushroom beauty is not only orange and poisonous, but when young can glow an eerie green in the dark. Yes, it's a fungus, so technically not a plant. It grows and "fruits" but has no real stems, roots or flowers. Jack O' Lantern mushrooms grow on dead organic matter, often a root or piece of wood in the ground, or at the base of trees. It especially likes oaks. Its mycelium filaments have been growing underground for some time before they briefly send up mushrooms, their fruiting bodies. The mushrooms produce minuscule spores and then turn to mush. Jack O'Lantern mushrooms fruit any time from July to November when weather conditions are right. Don't eat them; just enjoy the show. — Ellen Nibali