Posted by cwcmastergardeners | Posted in Ask the Master Gardener column | Posted on 28-07-2014
University of Minnesota Extension
CROW WING COUNTY MASTER GARDENER PROGRAM
Ask the Master Gardener
AUGUST 2014 COLUMN
Dear Master Gardener,
There is a shady area in my lawn where grass won’t grow and I would like to replace it with a ground cover of some sort. On a list of ground covers I saw wintergreen, which I love, listed. Would it be a good choice for this area?
The short answer is “probably”. Hardiness is not the issue because wintergreen (Gaultheria procumbens) is hardy in USDA zone 3. It does, however, require part to deep shade and acidic soil that is moist and rich in organic matter. It has glossy, evergreen leaves that release the wintergreen scent when crushed; small, egg-shaped, white flowers in summer; and striking, edible, red berries in the fall. It grows from rhizomes that creep along underground, sending up short six-inch stems at intervals, slowly expanding its territory. Birds like it and it has lovely, burgundy fall color. It may not be readily available in local nurseries but it can be purchased from catalogs or—if you have it growing wild in your woods—it can be propagated from cuttings in the summer or from rooted suckers in the spring. People who like wintergreen-flavored chewing gum, toothpaste and candy are often unaware that their fresh, minty taste comes from oils from this hardy, beautiful, low-growing shrub. Native Americans used wintergreen medicinally because it has some mild analgesic and fever-reducing qualities, but most of us just enjoy its flavor.
Dear Master Gardener,
I was visiting a friend out east and noticed she has purple loosestrife in her garden. Isn’t it invasive and illegal? Is yellow loosestrife also invasive and illegal?
Lythrum salicaria (purple loosestrife) is a species native to Europe and has been commonly grown in perennial gardens. In nature, purple loosestrife lives where soils are wet or have shallow standing water. It has no natural enemies and is very aggressive and will choke out native vegetation. Because purple loosestrife is dangerous when planted near water, it is illegal to grow any of these plants anywhere in Minnesota. It was designated a noxious weed in 1987 and since then the sale and transport of this plant has been illegal. According to Minnesota statutes it is the responsibility of the occupant or owner of privately owned land or the person in charge of public land to control or destroy noxious weeds to prevent their spread.
Lysimachia (loosestrife) is not illegal in Minnesota and is a tough, easy to grow perennial with attractive foliage and showy flowers. Most loosestrifes spread rapidly and are considered “aggressive plants”. If you plant the species that spreads rapidly in your perennial garden, you may want to restrict its spread with a physical barrier or be willing to divide them on a regular basis. They thrive in rich, moist soils and grow well in full sun to light shade. Lysimachia ciliate (Fringed Loosestrife) is native to northeastern United States and is an elegant plant with a willowy appearance and small yellow flowers that blooms in mid summer. Two cultivars ‘Firecracker’ and ‘Purpurea’ have chocolate purple colored foliage. This species spreads slowly. Lysimachia clethroides (Gooseneck Loosestrife) is a species that produces uniquely shaped, arching white flowers and blooms in mid to late summer. Place it carefully because it is invasive.
Dear Master Gardener,
The bats are driving us batty. They hang at night near our covered entryway and we wake up to piles of droppings and streaks of urine on our cedar siding. Is there anything we can do to stop them?
There are seven species of bats in Minnesota. They are actually gentle, beneficial creatures, but sometimes they become a nuisance. Bats come out at night, fly around, eat lots of insects and may rest under the eave of a porch. They are simply in need of a short-term roost. Bats will often stain the sides of a building with their droppings as they are flying in and out at night. Bat droppings are dark in color, greasy, and may have insect body parts inside. According to the Minnesota DNR, ultrasonic devices are not effective in repelling bats and there are no chemicals registered in Minnesota for use on bats. Attempts to poison bats, or exclude them using inappropriate methods can actually increase human contact, as sick or homeless bats may disperse through the neighborhood thereby increasing chance encounters with people or pets. Light sometimes will deter bats, so you could light the area at night to try to discourage bats from resting in your entryway. You could also provide an alternate roost site for the bats by putting up a bat house. Encouraging bats to stay around your yard will help control the insect population.
AUGUST GARDEN TIPS
• August can be hot and dry. Help Mother Nature out and give trees several deep waterings this month. They will enter winter stronger when well-hydrated.
• Stop fertilizing roses and other shrubs. Fertilizer encourages new growth that is more susceptible to winter injury than old wood.
• Dig up and divide irises and other spring-blooming perennials. Keep them well-watered.
• Keep weeding. Remove them before they set seed, which will produce a multitude of new weeds next spring.
• This is a good month to begin a new lawn, either by seeding or sodding.
• Remove and destroy tomato leaves with yellow or brown spots. These symptoms are caused by septoria leaf spot and early blight.
QUESTIONS OR COMMENTS?
Crow Wing County Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. All information given in this column is based on research and information provided by the University. To ask a question, call the Master Gardener Help Line at 218-824-1000, extension 4040 and leave a message. A Master Gardener will return your call.
UMN Extension Crow Wing County Master Gardeners’ Website