Category: Outdoors

Asian jumping worms take over

After decades of improving my garden soil, I have an infestation of Asian jumping worms. They can eat all the organic material in the soil, depleting it terribly. These foreign invaders multiply more quickly than our common worms, outcompeting them. Everything I have read about them says they are bad news for gardeners.

Scientists are working on organic solutions to the Asian jumping worm problem. I was able to phone Brad Herrick, a researcher at University of Wisconsin who has been studying them for years. He explained that although they came to the United States nearly 100 years ago, the worms are spreading rapidly, now infesting 37 states. Their worst impact may be in the forest: they eat dead leaves and forest duff, potentially creating a soil devoid of the organic matter that nourishes native wildflowers and trees. The soil can become sterile.

To see if you have them, start at a shady, mulched bed — that is where they like it best. Pull back leaves or mulch on your soil. The worms are surface feeders, living in the top inch or two of the soil, and readily seen on the soil surface. Touch one and it moves fast, wiggling and moving — quite a contrast to our relatively sluggish ordinary worms. The soil in infested areas often looks like it has coffee grounds spilled on the soil — which are their castings or excrement.

The clitellum that produces the egg sacs or cocoons is a whitish band near the head end of the worm. This contrasts with our common worms, which have a reddish-brown clitellum that is usually a bit raised.

Brad Herrick explained that unlike the earthworms we know and love, these guys can reproduce asexually, so even one worm can start an infestation. But they also spread when the cocoons, which sit on the soil surface, are washed away by rains. This allows them to expand their territory quickly, especially on hillsides.

How did I get them? I don’t know. They may have arrived when I bought plants for a new flower bed. I know my source of compost and know it has been heated sufficiently to kill all the weed seeds, so that would have killed any cocoons, too. And I see none of the worms in my purchased compost pile. But I had work done on my septic system, and soil was brought in.

According to Brad, freezing temperatures kill all the adult worms each winter. Unfortunately, it does not kill the eggs, which over-winter and start the cycle again. The eggs hatch once the soil temperature reaches 50 degrees, perhaps in April or May. He said it takes 70 to 90 days to reach maturity, at which point they start producing eggs; they continue to produce eggs from late June until frost.

So what can you do? If you have a new infestation you can try removing them by hand. Scientists often use a solution of yellow mustard powder in water to get worms to come to the surface. One third cup per gallon of water. But if you have a large area, that might not be practical. The best time to do this is in early summer before new worms have reached maturity.

Brad said you can heat the soil to kill the worms by solarizing it with clear plastic. Worms — and castings — will self-destruct at 104 degrees for three days, perhaps less. Unfortunately, that will not work in forests or shady beds, which is where I have them.

The worms can live in sunny beds if they are mulched. In fact, Brad told me, the worms have an enzyme that allows them to eat wood mulch. I wonder if mulching with peastone or small gravel instead of bark mulch or leaves might help to reduce the problem. If they run out of food, they may well die out. That theory has not been tested, and you may not like the look of a stone mulch. If you do this, please let me know if it helps.

My worm problem so far exists only in one large shady area. Here’s my plan: After frost I will rake off leaves and mulch (and collect and destroy any worms I see). Worms are usually within an inch or two of the surface. I will treat those leaves as toxic waste as they probably will have cocoons in them, which I don’t want to get into my compost pile

Hopefully I can burn my rakings in the driveway to destroy the leaves and cocoons. Then I will cut back all my perennials and go over the area with a flame weeder. This is a torch attached to an 8-gallon propane tank that sends out a big flame. That should burn up the cocoons on the soil surface. Flame weeders are available from Johnny’s Selected Seeds or Fedco seeds.

Brad told me of a product, BotaniGard, that contains a fungus that is listed for use to kill the worms. However, according to a University of Vermont study I read, it is only about 70 percent effective in a lab setting. That is not good enough for me, especially since even a solitary worm can produce viable eggs. And it sells for $90 a pound.

When buying nursery stock, look for coffee grounds on the surface of the pot, and when removing the root ball, look for worms. If you see either, do not plant it, and report the problem to the seller. Check purchased compost for worms, too. Clean your tools and shoes if working in beds with worms — the egg cocoons are tiny and not visible to the naked eye.

Featured photo: Jumping worms usually have a white clitellum and move fast when disturbed. Courtesy photo.

A few flowers that attract butterflies

Monarchs are on the move! It is time for their long trip to Mexico to spend the winter. And like marathon runners, they need to bulk up on calories before the event. You may have let a patch of milkweed grow on the edges of your property to support them. That is great, and many of us have done that. But the milkweed plants are for the caterpillars to munch on. Right now they offer nothing to monarchs. Our monarchs need blooming flowers for nectar and pollen.

Of the monarchs I see floating around my gardens, three plants seem most attractive to them for feeding right now: Joe Pye weed, goldenrods and asters. Let’s look at these and their garden worthiness.

Joe Pye weed is a native wildflower that likes stream edges and places with good moisture, though it will grow almost anywhere it is planted. It is a big plant, often 5 or 6 feet tall in the wild. It is a clumping plant, with the clumps getting bigger every year.

It is readily found in plant nurseries, although most sold are a named cultivar, one called “Gateway.” I have found that Gateway blooms longer and does better in a vase than the truly wild ones that have popped up along my stream. There is now a smaller Joe Pye that is called “Little Joe” that only gets to be 3 to 4 feet tall. It is a patented variety that does not breed true, and is actually a different species in the same genus, Eupatorium dubium. Then there is one called “Baby Joe,” but I have not yet tried either one.

The flowers of Joe Pye weed are a light purple and appear in large panicles at the top of the plant. The stems of Gateway are a deep purple, though the wild ones tend to be greener. Plant Joe Pye weed where you want it as the fibrous roots go deep into the soil, and when firmly established they are nearly impossible to dig out.

Goldenrods are a wonderful though frequently maligned genus of plants. For many years they were prohibited in arrangements in the flower room at our county fair, as it was believed they caused hay fever. They do not. They have a heavy, sticky pollen that does not fly in the air but is transported by insects. There are at least 20 species of native goldenrods, including some that prefer shade, while others demand full sun.

Goldenrods are important not only for monarch butterflies but also for many butterflies, moths, bees and other pollinators. And yes, some of the big, sun-loving species will expand their territory and send tenacious roots deep into the soil, even muscling out some dainty perennials.

Years ago I purchased some blue-stemmed goldenrod at The Garden in the Woods in Framingham, Massachusetts. I grow it in dry shade and in rich soil in moist shade. It has never been a pest or traveled around my garden beds, staying just where I planted it, blooming in September and into October. It is quite dainty.

My favorite goldenrod is a variety called “Fireworks” of the speciesSolidago rugosa. It prefers full sun and moist soil, but I have also grown it in part sun and fairly dry soil. Its flowers are tiny, blooming first at the tips and working their way down the 3- to 4-foot stems. The stems arch gracefully like a fireworks display. They can be divided every three to four years to keep the clumps to a manageable size and to increase (or share) them.

All the asters and aster-family flowers are great for monarchs and other butterflies. Scientists don’t call the genus aster any more, but Symphyotrichum, which is a shame as it is much less user-friendly.

There are at least 30 species of asters that grow wild in America, including many nice shade-loving ones that are certainly uprooted as weeds by tidy gardeners long before they bloom now, in the fall.

Asters have flowers with many rays and a bright yellow eye. They range from deep purple to white, along with pink and a light blue. All are quite tough, surviving any winter thrown at them.

Similar to asters, and a plant I just saw visited by a hungry monarch, is New York ironweed. It has smaller, deep purple blossoms in big clusters at the top of stems that can reach 9 feet tall.

According to Tracy DiSabato Aust in her fabulous book, The Well-Tended Perennial Garden, shorter, later-blooming plants can be created by cutting back all the stems to the ground when they reach 2 feet tall. I shall certainly try that next spring. I moved mine from moist soil to dry soil in partial shade partly because it got too tall in the full sun.

If you care about your monarchs, plant native plants. Native plants are much more useful to pollinators and wild animals than plants imported from other continents. Many of the native plants are just as beautiful and pleasing to me in the garden, and hopefully they are to you, too.

Featured photo: Monarch feeding on New York ironweed. Courtesy photo.

How to build hedges and fences

While vacationing recently on the Maine coast I admired many nice gardens. Many of them had hedges or fences, more than I am used to seeing in rural New Hampshire.

When settlers first arrived in New England they dug out stones left by the glaciers some 10,000 years before. They piled them up to clear farm fields, and began making stone walls to define property borders and to contain animals — or to keep them out. Gradually dry stone wallers learned how to make them look good and last forever.

Building a stone wall or retaining wall is hard work, and expensive to have someone else build. If you want to build your own, remember three things: First, the soil moves in winter as it freezes and thaws. This can make walls tumble if not properly built. Wallers have learned to add drainage under and around a wall: at least a foot of one-inch crushed stone in a trench beneath the wall works well. Round pebbles will act as ball bearings would, allowing stones to move.

Each stone should touch four others, two below it, two above it. Stones should not be stacked one on top of another, much the way bricks are laid. This helps to tie it all together and prevent movement.

Lastly, use a long string to keep the wall straight and level. Or if you are creating a curved wall, define it carefully before starting. You can place a garden hose on the soil to help define the curve.

Early settlers also made wattle fences. I talked to Crow Boutin, who makes his living making wattle fences in the Kennebunk area of Maine. These fences are simple: He cuts lengths of fresh yellow birch that are 1 to 2 inches in diameter. First he makes “pencils” that he drives in the ground with a hammer after he cuts them to length and sharpens them with an ax. Then he weaves pieces of birch 8 to 10 feet long between the vertical pencils that he spaces about 16 inches apart. The tension of the bent stems holds the fence in place. Simple? You bet, and something you could try.

But why do people need fences or hedges? Some are just for the looks, or to create a backdrop for flowers. Others are to keep others from looking into the yard, or to keep animals in (or out). Let’s take a look at a few I saw.

The nicest fences I saw were white picket fences. Maybe I like them because my grandfather had one, and I remember it from my youth. They show off flowers well, and allow climbers to climb on them. But generally you have to pay someone to install them, and, as Tom Sawyer knew, you must paint them from time to time. Now these fences come in a variety of materials including fiberglass or plastic that needs no painting.

Living fences — hedges — come in a variety of species. Evergreen hedges like yew or arborvitae can look good summer and winter, but are often eaten by deer. Hemlock and pine are less likely to be predated by deer, but they will grow to 60 feet tall unless they are trimmed every year and most somehow escape and do get tall.

Rugosa roses are commonly used as hedges on the Maine coast. They will grow in sandy soil and produce copious fragrant flowers and handsome red fruits in the fall. But they look bedraggled over time, and aren’t green in winter. Their thorns do keep people and pets from cutting corners through the yard.

Lilacs look great when blooming and have handsome green leaves eight or nine months of the year, but do little to block the view of your house and yard in winter. They do best in sweet soil, so add limestone every year or three to keep them blooming nicely. Lilacs, too, need trimming or they can get gangly.

The split rail fence is generally made of cedar, which lasts a long time — up to 20 years. It creates a rustic look, but neither keeps animals out nor blocks the nosy neighbor’s view. It will keep cars from parking on your lawn, and can support vines like roses or clematis.

Less common fences include stockade fences, which are tall wooden fences that block all view of the yard. These are what you need if you like to sunbathe nude in the garden and have a near neighbor. Definitely not a friendly signal to neighbors. Iron rail fences, wire fences and chain link fences all have their uses, but I can’t imagine having one installed.

Lastly, there is the deer fence. Many gardeners use them in order to grow vegetables, or to have tulips in the spring. Nowadays there are woven plastic fences that are inexpensive and come in 8-foot widths that work well to keep out deer. You can install them yourself on posts or stakes you cut in the forest. They work — unless you leave the gate open! Me? I have depended on having dogs to scare away the wildlife for many years. They did the job well, though I am now looking to adopt a dog as my corgi, Daphne, passed away a year ago. And I love dogs, too, which I can’t say for fences.

Featured photo: You could build this simple wattle fence. Photo courtesy of Henry Homeyer.