Dear Master Gardener: The deer are ruining my gardens and it seems worse this year than ever before. They are eating plants right next to my house. Are there any deer-resistant plants or proven repellents?
Answer: There seems to be more complaints this year about deer destroying gardens. In late summer and fall you may see freshly raw places where the bark has been skinned on the trunks of shrubs or young trees. Bucks remove the velvet from their antlers on young shrubs and trees, causing open wounds which can kill the plant. Deer usually feed at dusk and dawn and browse on twigs, foliage and flowers causing damage to gardens. They have no upper incisor teeth, so they tear off their food and leave behind torn, ragged vegetation. Going out to your garden in the morning only to discover that your beautiful hostas look like celery stalks sticking out of the ground is very disheartening. In the summer when food is plentiful you would think that deer wouldn't need to feed from our gardens, but our garden plants are kept watered and are therefore more succulent than plants in the wild, not to mention easier to get at.
The only true "deer-resistant" plant is a plastic one. With that said, you can minimize the damage they can do by avoiding plants they prefer and planting those they tend to pass up. Some deer favorites include daylilies, hostas, hydrangeas, lilies, roses, strawberries, sweet potato vine, tulips, arborvitae and white pine. Deer usually avoid plants that are toxic, have leaves that are fuzzy, tough and leathery, have spines or bristles, or are aromatic. Perennials that are reported to be non-preferred plants are: Achillea (yarrow), Aconitum (monkshood), Alchemilla mollis (lady's mantle), Allium, Aquilegia (columbine), Astilbe, Baptisia (blue false indigo), Narcissus (daffodil), Paeonia (peony), Perovskia (Russian sage), Pulmonaria (lungwort), Salvia, and Stachys (lamb's ear). Annuals that deer seem to avoid include ageratum, wax begonia, heliotrope, sweet alyssum, dusty miller, and marigolds. Even plants they do not like to eat, they will pluck out of the ground, spit it out and leave it to shrivel and die. Shrubs that are reported to be "deer-resistant" are lilac, nannyberry, juniper, spirea, Russian cypress and barberry. Winter is the worst time for deer in our cold climate and with little food available they will eat almost anything they can reach, including prized dwarf evergreens and the developing buds of deciduous trees and shrubs.
Once deer find your garden in winter, they will return each year throughout their lives, so it is important to deter them from the outset. In our cold climate shrubs are more vulnerable to deer browsing, so many gardeners put black plastic or nylon netting over their shrubs to protect them. Burlap can be placed around arborvitae, which not only protect them from deer, but also winter burn. Snow fencing around vulnerable and/or prized trees and bushes can be used. Some gardeners put fencing around each garden bed, as deer are usually afraid to jump into small areas where they could get stuck.
There are commercial deer repellents. Some people have success with Milorganite, which is a granular product composed of heat-dried microbes that have digested the organic material in wastewater and is manufactured by the Milwaukee Metropolitan Sewerage District, so you not only get a possible deer repellent but fertilizer too. Some commercial repellents are in liquid form and sprayed on. They typically contain a variety of ingredients including, but not limited to, eggs, garlic, castor oil, the urine of predatory animals, and capsaicin (hot pepper sauce). Homemade versions have the same main ingredients as their commercial counterparts. If you are going to use repellents, it is important to apply them regularly, especially after heavy rain or snow. Some gardeners have success with hanging bars of soap from trees, but experiments conducted by R.K. Swihart and M.R. Conover (1990) showed that only approximately one yard from the soap will be protected from deer, some damage to plants can happen, and there is no one brand that repels better than another. If you are interested in reading a book about garden remedies you may enjoy, The Truth About Garden Remedies What Works, What Doesn't, and Why by Jeff Gillman, a former University of Minnesota associate professor in the horticultural department.
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Dear Master Gardener: I need to replace some old and overgrown shrubs in my yard. I would like to plant ones that have berries, some for me and some for birds and other wildlife. What do you suggest?
Answer: Even in our cold zone three climate there are many to choose among. Here are some listed in three categories: edible, tall (over four feet), and short (under four feet). Though we usually try to include botanical (Latin, official) names, this time, in consideration of numbers and space, common names will be used.
First are some edible shrubs: Juneberry (sometimes called serviceberry), bearberry, chokeberry, wintergreen, sandcherry, sumac, gooseberry, rose, raspberry, dewberry, thimbleberry, buffaloberry, wolfberry, blueberry, viburnum, and snowberry. Though all of them do bear fruit, not all will be equally suitable for your purposes. Consider height, need for sun or shade, and soil type. Also, remember that some berries that wildlife enjoy are not as palatable to humans, and that you may not want your wild friends competing for your favorites. Not all berries are ready to eat right off the plant, such as sumac and rose hips, which are steeped for tea, and chokeberries, which must be processed.
Tall shrubs may grow to be eight or ten feet tall, though most can be kept pruned shorter or come in dwarf varieties. Some attractive tall shrubs are serviceberry, winterberry (berries are poisonous), elder, buffaloberry, and various viburnums.
Heights of short shrubs need to be carefully considered because some, such as bunchberry and bearberry, are so short (six inches) that they are really ground covers. Here are some short shrubs: sandcherry, currant, rose, bearberry, blackberry, bunchberry, swamp fly honeysuckle, raspberry, wolfberry, and blueberry.
The internet can give you a great deal of information about individual species. As always, university-based sites are science-based and likely to be the most accurate.
Crow Wing County Master Gardeners are trained and certified volunteers for the University of Minnesota Extension Service. 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 824-1000, extension 4040 and leave a recorded message. A Master Gardener will return your call.
October garden tips:
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• Plant tulips this month. Clusters of a dozen bulbs or so make greater impact than do bulbs planted in lines.
• Continue to water trees (especially evergreens), shrubs, perennials and lawns so that they tolerate winter better.
• Lift and store tender bulbs such as cannas, gladiolas, and dahlias after the first frost.
• Continue to weed, weed, weed.
• Mow lawns to a 3-inch height going into winter.
• Divide and transplant peonies now.
• Cover strawberries with a thick layer of straw or hay late this month or after several hard frosts.
• Get your soil tested.
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• Prune trees that bleed or are susceptible to disease such as oak, maple, birch, honey locust, and mountain ash.
• Clean up fallen apples, apple leaves with spots, and tomatoes that had disease, disposing them off your property. Many diseases and insects overwinter in plant materials.
