I’d be willing to bet that you have one or even many invasive plants on your property.  Norway maple:  invasive.  Lily-of-the-valley:  invasive.  Orange daylily, burning bush, baby’s breath, European mountain ash, forget-me-not, white mulberry, bishop’s weed, red-twig dogwood, periwinkle, violets, boxelder, honeylocust, bush honeysuckle, creeping bellflower, shasta daisy, amur maple, common privet, Japanese barberry, yellow water-flag iris, staghorn sumac:  all invasive.

            June is invasive species awareness month in Wisconsin.  I hope that everyone has at least heard of the big three – buckthorn, purple loosestrife and garlic mustard – that are degrading our natural areas by crowding out native plants.  Some more recent invaders are dame’s rocket, a plant that resembles garden phlox except that it has 4 petals instead of 5, blooming along roadsides now in purple, pink and white; and teasel and reed canary grass.

            A drive along Hwy. 41 is like touring a living museum of invasive plants.  The ditches are lined with cattails, teasel, Canada goldenrod, purple loosestrife, dame’s rocket, reed canary grass, garlic mustard, tansy, Canada thistle and phragmites, an 8-foot tall grass topped with big fuzzy plumes in fall.

            But let’s get back to your yard.  You know that Norway maple is invasive – how many hours have you spent pulling maple seedlings that have sprung up from those pesky “helicopters” in your flowerbeds, sidewalk and driveway cracks?  If you’ve got lily-of-the-valley or violets, the joke is on you if you thought they’d stay where you put them.  What about bishop’s weed, also called snow-on-the-mountain?  Many people, and their neighbors, are sorry they ever planted it.

            If you live in the city or in a well-manicured subdivision, it may not be obvious to you why some plants considered invasive made the list.  But if you live within a mile of the edge of town, or a park, empty lot or natural area, you need to be aware and careful of what you plant.

            My neighbors planted a large area with dame’s rocket several years ago.  Now the ditches and field edges for miles in every direction are blooming with purple and pink.  Another neighbor had two teasel plants on his property four years ago.  He ignored my polite request that he cut them before they went to seed.  Now teasel populates  the open fields for two miles in every direction from his property.

            I am not suggesting that you immediately rip every potentially invasive plant from your landscape.  Unless you have buckthorn, that is, then get rid of it!  Just educate yourself as to which  plants are or have the potential to become invasive, keep them under control and replace them when possible.

            Before you plant anything new, consult a list of invasive plants to see if your selection is on the list.  You will be amazed at how long these lists are!  A great reference book is Invasive Plants of the Upper Midwest by Elizabeth Czarapta.  These two websites have comprehensive lists and good photos:  www.ipaw.org and www.dnr.state.wi.us/invasives.

      Winnebago County is being taken over by alien invaders!  Invasive alien plants, that is.  Take a walk along the Wiouwash Trail.  Here you should see native prairies and forests since this land hasn’t been cultivated or disturbed for many years.  What do you see instead?  Wooded areas have been overgrown by buckthorn, wild grape vines and garlic mustard.  The prairies are overgrown with trash trees and weedy shrubs.

      The same is true for forgotten areas behind garages and along fence lines.  Buckthorn and garlic mustard are especially sneaky at hiding in shady areas in the back of flower beds or right next to multi-stemmed shrubs like lilac, spirea, dogwood and highbush cranberry.

      Many invasive plants arrived in the United States from Europe.  They were either brought over intentionally as ornamental or useful plants for gardens, or unintentionally when seeds hitchhiked with some other cargo or plant.  The problem is that the natural controls, insects or other predators, did not come with the plants, allowing them to grow unchecked.

      Garlic mustard is a prime example.  European settlers brought it to the new world as a cooking herb and it has been slowly spreading west and northward ever since.  It crowds out native woodland plants like trillium, bloodroot, trout lily, anemone, spring beauty and wild ginger. 

      The roots of garlic mustard emit a chemical that kills the fungi in the soil that should have been food for many tiny insects.  When the smaller insects die, the larger insects that eat them die, then the birds that eat the insects starve and the effects move on up the food chain.

      Garlic mustard attracts butterflies to lay eggs, but a chemical in the plant poisons the eggs or the larvae so butterflies never form.  

      You can help control garlic mustard by pulling it whenever you see it.  It pulls up easily in early May just before and during flowering.  Do not compost the plants or let them lay on the ground, as they will continue to grow and set seed even after being uprooted.  Each garlic mustard plant produces several hundred seeds which are viable in the soil for up to seven years.

      To see what garlic mustard looks like, the Invasive Plants Association of Wisconsin has good photos on their website:  www.ipaw.org.

      Some gardeners love moss.  Some gardeners hate moss.  Some gardeners love moss in some places but hate moss in other places.

      Moss growing in your lawn is actually a symptom rather than the cause of a poor lawn.  Moss grows in shade where soil is compacted and has a low pH.  Poor drainage and mowing too closely also encourage the growth of moss. 

      The kind of moss growing in your lawn will actually tell you what the problem is.  Mosses with an upright growth habit, green growth at the top and brown stems at the base indicate dry, acidic soil.  Trailing mosses with a flat growth pattern and pale green foliage and stems are symptoms of a shaded lawn with poor drainage.  Cushion mosses have tiny upright stems and a compact, dense growth habit.  They appear in lawns mowed too closely to soil level. 

      If you don’t like the moss, remove it using Safer Brand Moss & Algae Killer, a soap-based product that does not harm the environment.  If the underlying problems are not corrected, however, the moss will return.  Power raking will take care of all the above problem conditions.  Top dressing with compost, aerating the soil and raising the mower blade will help as well.

      Some people enjoy the beauty of moss and want to encourage it in their lawns.  Just looking at the green color of moss reduces stress, and a shady, mossy area can add a degree of serenity to any landscape.  Growing moss is becoming an increasingly desirable low-maintenance alternative to grass lawns. 

      Moss is best in areas that are not high traffic as it does not stand up to heavy wear.  Moss lawns may be planted in spring or summer.  Work compost into the soil, water, then lay down cushions or mats of moss, including some of the earthy matter in which it was growing – pine needles, rotting wood, forest litter.  Press the moss down firmly.  If you do not have access to already growing moss that you can transplant, it can be ordered over the internet.

      Spray the moss with 1 quart buttermilk mixed with 2 gallons of water in mid-spring to encourage growth.  To start moss in a new area, put a clump of moss in a blender with buttermilk and water and mix together.  Spread it where you want moss to grow.  Yogurt can be used in place of buttermilk.  You can give terra cotta, metal and stone pots and even rocks newly added to a landscape a prematurely aged look by spreading the moss mixture on their sides.  A few ounces of potters clay added to the mixture in the blender will help it stick better to rocks.

      Mist the transplanted material and new growth daily and do not walk on it until it is well established.  Occasional weeding is all the maintenance needed.

      Common buckthorn and glossy buckthorn were introduced to the United States in the 1800s as tough, hardy shrubs for the landscape.  That toughness has made buckthorn aggressively invasive to the point where it is crowding out native flowers in woodland areas, forming an impenetrable understory layer, destroying wildlife habitat and causing long-term decline of forests by preventing the growth of native tree seedlings.

      Buckthorn also spreads easily into savannas, prairies, abandoned fields and roadsides, forming dense thickets.  In your yard, you many find buckthorn spouting up within the branches of other multi-stemmed shrubs or in a neglected corner.

      Buckthorn is easiest to identify in late fall; it is the only tree or shrub still holding onto its green leaves.  Common buckthorn leaves are rounded to egg-shaped with finely toothed margins.  The leaves are very dark, dull to glossy green.  Glossy buckthorn has dark green, glossy, oval-shaped leaves.  A good way to make a positive identification of either species is to scratch the surface of a trunk or stem.  If you find orange inner bark it is buckthorn.

      Both species grow 10 to 25 feet tall and may be either trees or shrubs.  There are separate male and female plants with only the female producing berries.  In fall the berries turn black and are much loved by birds throughout the winter.  Each berry contains 2-4 seeds that are poisonous to humans.  The berries have a laxative effect on birds which ensures the spread of the seeds throughout the habitat.  Thousands of buckthorn seedlings can sprout within the area of one mature tree.

      Buckthorn is best controlled by pulling the seedlings when they are less than a half inch in diameter.  It is easiest to do when the ground is moist after a good rain. 

      Larger trees and shrubs must be cut and immediately brushed or sprayed with an herbicide containing triclopyr such as Garlon 4 or Ortho Brush-B-Gone.  Cutting the trees or shrubs without the herbicide follow-up is worse than not cutting them at all since they will re-sprout heavily with more branches than before.

      Smaller trees, with less than a 6-inch diameter may be treated using the basal bark method.  They need not be cut before herbicide is applied.  Apply the herbicide at the base of the plant, wetting the bark from the soil-line up to about 12-15 inches.  Spray so that the trunk becomes thoroughly wet, but not to the point of runoff.  Each stem of the plant must be treated.

      The best time of year to treat buckthorn with herbicide is late fall when the sap is flowing toward the roots.

      Good gardeners know that before choosing a plant for a specific location, some research should be done as to what plants grow best in the conditions at the site.  You wouldn’t plant shade-loving hosta on the hot, dry south-facing side of the house anymore than you’d plant tulips in the deep shade of an evergreen or a cactus in the bog garden.

      There is one more factor to take into consideration.  We need to educate ourselves on which plants are considered invasive and to refrain from planting them.. 

      The Invasive Plant Association of Wisconsin (IPAW) categorizes plants this way:

• Invasive Plants are non-indigenous species or strains that become established in natural plant communities and wild areas, replacing native vegetation.
• Weeds are undesirable and troublesome plants growing in disturbed areas, especially cultivated ground.
• Potentially Invasive Plants are species that are invasive in parts of North America having similar climates and plant communities, and that are thought to have the potential to colonize and become invasive in Wisconsin.
• Indigenous means occurring naturally in a specific area or plant community; not introduced.

      Many of us are familiar with the most famous invasives:  purple loosestrife, buckthorn, reed canary grass, various thistles and garlic mustard.  But there are many more invasive plants that are sneaking into Wisconsin.  I was recently asked what the pretty yellow ground cover was that grows along Jackson north of Oshkosh.   The homeowner wondered if it would be a good plant for a berm alongside their road and asked if it grew from seeds or where they could buy it.  I knew without driving down Jackson that they were referring to bird’s-foot trefoil, a rapidly spreading plant that was planted along roadsides to control vegetation and that now has spread tremendously and crowded out native vegetation.  My reply to the question was a more tactful version of “DON’T PLANT THAT!” and then I suggested an alternative or two.

      You would be surprised at what plants are already considered invasive or have the potential to become so.  Here are a few plants considered invasive that you might not know about:  orange daylily, Norway maple, Russian olive, Queen Anne’s lace, forget-me-not, several honeysuckles, white poplar, multiflora rose, Canada goldenrod, tansy, common periwinkle, black locust, cattails, Japanese barberry, tree-of-heaven, burning bush or winged euonymus, white mulberry, willows, English ivy, European highbush cranberry, creeping bellflower, lily-of-the-valley, oxeye daisy, baby’s breath, yellow or water-flag iris and spearmint.  There are many more and I haven’t even listed the grasses and water plants.        

      You don’t have to memorize a long list of plants to avoid, but I urge you to take a look at IPAW’s website:  www.ipaw.org or the book Invasive Plants of the Upper Midwest by Elizabeth Czarapata to at least get a feel for what plants might be invasive before you plant anything new in your yard.

      In spring the woodlands are full of beautiful wildflowers – bloodroot, anemone, May apple, trillium and more.  Sadly, there are many areas where these beautiful spring ephemerals have been choked out by a rapidly spreading invasive plant called garlic mustard. 

      Garlic mustard is rather pretty itself, with small white flowers and lacy-edged green leaves, but it has the potential to totally dominate a forest floor in a few years, shading or crowding out native wildflowers and tree seedlings before they have a chance to grow.  This can have a disastrous effect on birds and other forest wildlife as their food sources disappear.

      High Cliff State Park on the northeast corner of Lake Winnebago has a terrible garlic mustard problem as does Devil’s Lake State Park near Wisconsin Dells.  On a walk through the woods in the spring you will find a two-foot high carpet of garlic mustard completely covering the forest floor as far as the eye can see.

      Garlic mustard is a biennial plant.  It grows a rosette of leaves its first year and in the second year a taller stalk appears with many small white flowers.  It blooms from late April through May.  Seed pods begin to form soon after flowering begins.  Each plant produces hundreds of seeds and they are viable for five to seven years. 

      In the United States, garlic mustard has no natural enemies, although the University of Minnesota is experimenting with a weevil that may be a method of biocontrol available in a few years.  For now, the best way to control garlic mustard is to pull it.   It pulls easily from the ground just before and during its flowering period.  But it is a tricky plant.  If you pull it and lay it on the ground the plant itself will wither, but the flower stalk will turn at a 90 degree angle and grow straight upward, produce flowers and setting seed.  It does everything it can to ensure its own survival!  Therefore, when garlic mustard is pulled, it should be placed on a hot driveway or parking lot to die completely, or bagged and removed from the site.

      Dandelions are the enemy of many a lawn perfectionist.  This year, think twice before dousing your lawn with weed killer – those dandelions have many health benefits. 

      When the leaves first appear, they are sweet and tender.  After the flowers appear, the leaves become more bitter.  Dandelion leaves are a healthy addition to your salad, soup or stir-fry at either stage, providing vitamins A and C.  Dandelion is best known as a liver cleanser and a mild diuretic.  A tablespoon of fresh or a teaspoon of dried dandelion root in one cup of water makes a healthful tea.

      Chickweed is another lawn plant with many useful properties.  Chickweed is a prostrate plant with tiny smooth leaves and small white flowers that bloom throughout the growing season.  Chickweed is classified as a demulcent herb, which means it soothes and softens the skin and mucous membrane surfaces.  Salves, oils or ointments can be made from chickweed and used for healing the skin. 

      Like dandelion, chickweed can be added to salads, soups or stir-fries, for internal soothing.  Chickweed is an expectorant, a word you’ve probably seen on cough medicines.  Taking it internally helps a cough becomes more productive and also paves the way for healing of toxicity related problems such as poor circulation, psoriasis, lung inflammation and skin problems.

      Plantain isn’t the most beautiful plant, but if you get stung by a bee you’ll be glad to have some growing in your lawn.  Just crush one of its large leaves and gently rub the juice on the sting for fast relief.  You can recognize plantain by its wavy-edged veined leaves growing basally from the ground.  Stiff green leafless flower stalks grow from the center of the plant.

      Along with relieving the pain of bee stings, crushed plantain leaves help heal bites, cuts, scrapes and burns.  Internally, plantain leaf tea is a remedy to soothe inflamed and infected tissues of the respiratory, urinary and digestive tracts.  Chewing the leaves eases the pain and inflammation of infected gums.

      To make an oil from any of these herbs, first dry them, then crush them to a coarse powder.  Stir them into olive oil heated in a crock pot to about 100 degrees F. and let them heat and soak for three to five days, stirring a few times a day.  Strain the oil and bottle it.

      To make a salve, pour the herbal oil into a saucepan or double boiler.  Add about ¾ oz. grated beeswax per 4 ozs. herbal oil and heat and stir gently to melt the wax.  Let it cool for five minutes. Add 10 drops of your choice of essential oils.  Pour the warm salve into small glass jars and let cool and harden. 

      There are many good books with recipes for different combinations of herbs and essential oils.  I recommend Better Basics for the Home by Annie Berthold-Bond.

      Have you seen black and yellow striped beetles crawling around the blossoms of your cucumbers, zucchini, squash, pumpkins and melons?  They are cucumber beetles and along with chewing holes in your plants, they spread disease.

      The beetles lay small orange eggs at the base of the plants from April to June.  The slender white larvae weaken plants by feeding on the roots and crowns.  Later in the season, adults chew holes in the leaves and flowers and even in the skin of the fruit.  They also transmit mosaic viruses which stunt or kill plants and disfigure fruits, and bacterial wilt, a disease that causes whole branches to wilt and eventually kills the entire plant.

      There are several non-toxic ways to deal with the pests.  Try one or a combination of methods. 

      Use a thick straw mulch around the plants to make it difficult for the larvae to climb onto the stems.  Reflective mulch, such as heavy-duty tin foil, while not pretty, works well too.

      You can cover the plants with a light floating row cover or cheesecloth, but this prevents pollinating insects from reaching the plants.  If you go this route, you must hand-pollinate the plants.

      Planting radishes, tansy, catnip, marigolds and goldenrod nearby repels cucumber beetles.  Next year, throw a few radish seeds right in the hole with the seeds of the crop you are trying to protect and let the radishes grow and go to seed.  Also for next year, plant a bit later, even early into June, so the blossoms don’t coincide with the adult cucumber beetle life cycle.

      If you are not squeamish, you can pick the insects off the plants and squish them.  A slightly less disgusting method is to scoop them up with a folded piece of paper and drop them in a bucket of soapy water.  Really revolting, but very effective, is to catch a lot of beetles and mix them in your blender with water.  Strain and spray the water onto the plants.  A more pleasant spray can be made by mixing geranium stalks and leaves in the blender with water, straining and spraying.  Make sure to spray the undersides of the leaves.

      Gardens Alive (www.GardensAlive.com or 513-354-1482) sells a powdered clay called kaolin which is mixed with water and sprayed on plants to deter insects.  The powdery film sticks to insects’ legs, wings and mouth parts so they quickly leave to find another place to feed or lay eggs.  The spray does not affect bees, earthworms or beneficial insects.  A 5-lb bag costs $24.95 but will last for years.

      As a last resort, use pyrethrins or rotenone to control large infestations.

      Governor Doyle has proclaimed June 2005 as Invasive Species Awareness Month.  Why does the governor care about invasive species?  Why should we care?  Just what is an invasive species?

      The Invasive Plant Association of Wisconsin defines an invasive plant as one that is a non-indigenous species or strain that becomes established in natural plant communities and wild areas and replaces native vegetation. 

      The governor’s proclamation states that millions of dollars, both public (your taxes!) and private, are spent each year for the control of invasive plant and animal species in Wisconsin’s waters, wildlands, and agricultural lands.  It goes on to say that invasive plants and animals threaten Wisconsin’s waters and wildlands by competing with and destroying native plants and animals, threatening the productivity and economic viability of Wisconsin’s agricultural lands and interfering with tourism and recreational users of the land and waterways.

      Governor Doyle realizes that the first step toward changes that can help prevent the introduction and spread of invasive species is awareness of the problem.  There are hundreds of events scheduled throughout June across the state at nature and environmental centers, state parks, state forests and university extension offices that will educate people about the problems associated with invasive species.

      But what can you do at home?  The first step is to be aware of what you plant.  Purple loosestrife is an invasive plant that is choking our waterways and wetlands, yet many people are unknowingly growing it in their gardens.  It is illegal to grow or propagate purple loosestrife in Wisconsin.  If it is in your garden, you could be fined.

      Another invasive plant in many of our yards is buckthorn.  Its glossy green leaves and formal shape, either upright or as a small rounded tree, add beauty to many landscapes.  But evil lurks in the beauty.  Birds eat the seeds which pass through their bodies intact and spread the plants far and wide.  Buckthorn can take over entire forests, destroying wildlife habitat, replacing native vegetation, and forming an impenetrable understory which prevents the growth of native tree seedlings. 

      Garlic mustard is another invasive plant that is taking over our woodlands and choking out spring wildflowers like trillium, bloodroot, Jacob’s ladder and wild geraniums.  You probably aren’t intentionally growing garlic mustard in your yard, but I have seen in growing prolifically on city lots in Neenah in shady spots in back corners of yards or behind garages.  The seeds are sticky and readily attach themselves to animal fur, clothing, auto tires and shoes. 

      If you have any of these plants on your property, please get rid of them!  If you are not familiar with them, good pictures and eradication methods can be found on the Invasive Plant Association’s website at www.ipaw.org.  Information on events for Invasive Species Awareness Month are at http://invasivespecies.wi.gov/awareness/.