University of Maryland Lecturer and Turfgrass Management Advisor Geoff Rinehart answers your questions about lawn weeds and fall fertilization.
Q: What is this “grass” and is it possible to eradicate it from our lawn? It has been spreading down the hill from our neighbor’s property. What’s the best way to bring our lawn back to a nice quality grass?
Answer: Japanese stiltgrass (Microstegium vimineum) is an invasive summer annual grass that is becoming more pervasive in Maryland. While it used to be more limited to just woodland areas, we are getting more reports of it infesting lawn areas in recent summers.
As is the approach with any weeds, practicing good turfgrass cultural practices to encourage a healthy, dense stand of grass is the cornerstone of any lawn management program. Mowing taller (3”-3 ½”), fertilizing based on University of Maryland recommendations, and overseeding annually with improved turfgrass cultivars are three practices that will help create greater density.
This summer has been a particularly difficult one for controlling summer annual grasses like crabgrass, goosegrass, and, of course, Japanese stiltgrass since these weedy grasses are favored by wet, hot conditions like the weather we had in July-September. Since Japanese stiltgrass is a summer annual, it can be deterred by applying a pre-emergent herbicide in the spring at forsythia bloom (which is a similar approach to crabgrass control). When watered-in, pre-emergent herbicides form a soil barrier to seed germination. However, most of these products only last 6-10 weeks (the lower part of this range when it is wet and/or hot, the upper part when it is dry and/or cool). This May was rather rainy, so if you applied a pre-emergent in early April, another should have been applied in June. Usually, two applications are enough to get us to early August and then summer annual weed pressure decreases as early cooler weather is usually a month around the corner. Read More
Both my sons enjoy growing plants inside their apartments – all that botanical indoctrination paid off! My younger son, Patrick, has now managed to grow food in his sunny 21st-floor Chicago flat: a nice little harvest of cucumbers.
Mums that are planted this late should be treated as an annual. They will not become established over the winter. Fall-planted asters, however, will become established. Ornamental kale and cabbage produce a nice show of foliage but usually decline by February. Pansies are a good choice for fall and winter color in the garden. This is a good time to save the seed from annual flowering plants like cleome, zinnias, cosmos, celosia, and butterfly weed.
Leave the flower heads on sunflowers, coneflowers, coreopsis, and black-eyed Susan to provide winter food for birds.
Be sure to discard badly-diseased plants and fruits; don’t till them back into the soil. All other plant waste can be composted or directly incorporated into your garden soil.
Carrots can be over-wintered in the garden by covering the bed with a deep straw or leaf mulch. Pull carrots through the winter as needed.
Lettuce, spinach, arugula, and kale can be planted through the middle of the month. Cover these late plantings with a cold frame, temporary greenhouse or floating row cover. Be sure to fertilize seedbeds, keep the soil moist and protect seedlings from pests. The young plants will go dormant and re-grow in Spring.
Photo: Beth Bukoski, University of Maryland Extension
Q: I found these orange bugs all over the milkweed I planted for Monarch caterpillars. What are they and what, if anything, should I do about them? I don’t want to harm other organisms.
A: What you have here are nymphs (juvenile stages) of Large Milkweed Bugs (Oncopeltusfasciatus). At this time of year, it is common to see these insects on different species of milkweeds throughout Maryland. The gray and black “insects” in your photo are actually cast skins of the young nymphs. Large Milkweed Bugs go through five instars (phases as nymphs) and shed their exoskeleton at each phase until they become fully developed adults. Read More
A team of UME Master Gardeners working with UME field faculty created an outstanding Learning Garden that inspired and educated residents during the 11 days of the Maryland State Fair. Practical, small-space gardening techniques were demonstrated in 25 distinct beds.
A dramatic “three sisters” bed served as the central point of visual interest, attracting people from across the fairgrounds: ‘Honeybush’ butternut squash at the base, sunflowers (instead of corn) growing upright, and ‘Algarve’ pole beans climbing to the top of the bamboo frame:
Black-eyed Susans are easy to grow and will attract many pollinators to your garden. The dark center or eye of the flower head holds 250 to 500 individual flowers, and to pollinators, each one of these is a shallow nectar cup. These are shallow enough that even small wasps and flies can drink from them, and many small wasps and flies are predators or parasitoids of pest insects. These tiny, dark flowers bloom from the outer rim of the eye and progress inwards with time. It’s a buffet that attracts a wide variety of small to medium-sized pollinators, including many species of insects beneficial for pest control. This blog provides a few examples of the wonderful insects you can attract to the home garden by planting Black-eyed Susans.
A Black-eyed Susan isn’t a single flower, it’s actually hundreds. Notice the individual corollas of the “eye”, and the yellow pollen along the outer ring which indicates those flowers are in bloom. Watch a pollinator visit, and you’ll notice that they rotate around, drinking nectar from each one of the tiny blooms in this ring. The Metallic Green Bee, shown here, is a good example of the small bees that enjoy Black-eyed Susan’s big, soft, landing pad and shallow flowers. Notice the pollen packed onto the bee’s hind legs. Read More