GreenYankee Blog

Biological Controls

in Gardening Guy: Henry Homeyer
datura, invasive, organic, pests, purple loosestrife

It’s not always easy to be an organic gardener. Even committed organic gardeners sometimes long to spray herbicide on gout weed or that pesky poison ivy. There are times when Japanese beetles or rose chafers arrive in throngs just before your garden party and you want to nuke those nasty critters. There may be times when you have an urge for the good old days, the time before you understood that spraying an insecticide kills beneficial bugs along with the bad, aggravating your pest problems. But there are also problems that are more easily addressed with organic solutions.

Right now purple loosestrife is blooming in swamps and along streams and roadsides. It is a tall, beautiful weed with small purple-pink flowers growing on square stems. So who can object to such a pretty plant? Biologists know that it is a plant that came from Europe and has few natural predators here to keep it from taking over wetlands. It has an amazingly robust root system and can elbow out native plants, in part, because it produces huge numbers of seeds. Not only that, the plant offers little of food value to our wildlife. It’s pretty, but worthless. A thug.

Purple loosestrife came from Europe in the early 1800’s –probably in soil used as ballast in ships – but it is not a problem there. Why not? It evolved there, and over time some 120 species of insects learned to eat it. Of these, 14 are host specific, meaning that they eat it – but nothing else. A few of these insects were brought to quarantine labs to test the following: Will they eat related species of the target plants, or plants that share a habitat? Will they attack any of our major crops such as corn, wheat and soy? Beetles have been found to help control purple loosestrife.

If you’ve ever tried to dig out purple loosestrife, you know that it has an amazing root system that will challenge even the strongest back. Scraps of roots left in the ground will start new plants. Not only that, each mature plant produces many thousand tiny seeds every year, so even if you did poison or pull one, the soil if full of tiny time-release capsules – seeds -  that will start the process all over again next year, and the year after that, and so forth. But it can be kept under control with the use of introduced beetles.

Since 1994 beetles that eat purple loosestrife have been successfully reducing stands of this exotic. They reduce the numbers of plants to around 10% of pre-introduction levels; as the numbers of plants drop, so do the number of the predator beetles.

Dr. Casagrande and his colleagues at the University of Rhode Island have been working on finding and introducing biological controls for major plant and insect pests. But it is a slow process. They have introduced 3 parasitic wasps to control the dreaded lily leaf beetle, that red pest that devours our Oriental and Asiatic lilies. When I asked him recently how the wasps are doing, he told me that they are well established in sites in Rhode Island, Massachusetts, New Hampshire and Vermont. That some have spread as much as 10 miles since introduction. However, the predator insects are not for sale – so we just have to wait for them to slowly make the way to our gardens.

So what can the home gardener do? First, realize that help is on the way – in the form of biocontrols. Second, recognize that herbicides for plants and insecticides for beetles ultimately don’t work. Yes, you can kill lily leaf beetles or loosestrife with a spray, but you can’t eliminate them. Patience is required as Mother Nature, with a little help from scientists, will eventually restore balance.

I have purple loosestrife near my stream. My control? I cut it down with my pruning shears, thus preventing the plant from producing seeds. When small plants appear in my flower gardens, as they have done, I dig them out before they establish a big root system.

I have given up planting Oriental and Asiatic lilies. Dr. Casagrande told me that there are a few cultivars of lilies that are less attractive to the pest beetles, such as ‘Black Beauty’. But instead of those lilies I now grow a lovely unrelated plant called angel’s trumpet (Datura spp.). The flowers are big white trumpets not unlike the lilies, but they bloom in sequence all summer, sometimes a dozen or more at a time. It’s an annual here that I re-plant every year. One note of caution: the seeds are poisonous if eaten.

As an organic gardener, I have to accept that I am not in total control of the environment and that sometimes I have to endure some losses. Biological controls do work, and have made some exotic pests such as birch leafminers into nothing more than minor annoyances. There are already places where purple loosestrife is no longer a problem.  I urge you to stay the course and be organic.

Henry Homeyer is the author of 4 gardening books, including his most recent: Organic Gardening (not just) in the Northeast, a Hands-On, Month-by-Month Guide. His e-mail is henry.homeyer@comcast.net.

Mid Summer Blahs

in Gardening Guy: Henry Homeyer
annuals, daylilies, flower gardening, flowers

August can be a tough month in the flower garden. Generally it’s hot and dry. Even the annual flowers that are supposed to bloom like the Energizer Bunny are tired and moody. I pulled some muscles in my back (foolishly moving big stones as if I were 25instead of 65) so the weeds in my garden got ahead of me, too. But now I am back at it, and trying to perk up my gardens.

The front walkway at my house is flanked by 2 flower beds, each just over 2 feet wide and about 8 feet long. In the spring I had Forget-Me-Nots (Myosotis sylvatica) and pansies providing color and verve, along with daffodils and crocus.  But all those are long gone – or dormant.

I planted a variety of annuals along the walkway including nicotiana, verbena, salvia, cosmos and a lovely plant called Persian shield (Strobilanthes dyerianus) that I grow for the rich purple and silver foliage. The verbenas were a fancy new variety but they have proved too tasty to some ambitious insect. The nicotiana (also called tobacco plant) is still blooming quite nicely in lime green and a brownish red. The cosmos are in bud, but currently flowerless. Annual poppies have come and gone. My salvias are showing just a few deep blue/purple blossoms.

The problem now is that most garden centers do not have a wide variety of blooming flowers for sale. Geraniums are still for sale in fire engine red, pink and white. And some places have expensive hanging planters, but my budget for $25 planters has run its course. So what can I do?

Daylilies, one of mid-summer’s heroines, are in their glory now. I could dig up a clump from elsewhere on the property and move it to the front walkway. Or I could visit a garden center and buy a potted daylily in bloom and move it into an empty spot left when I pulled weeds and the dozens of annual poppies that show up each year.

I realize that the common orange daylily has prejudiced some gardeners against the breed. They are so common that they are considered trite. We like the new, the different, and once I suppose the orange daylily fit that description. Another problem is that orange daylilies have roots that spread, and a small clump turns into a big clump in just a year or two. And they are hard to dig up. Not only that, even a small scrap of root will generate a new plant.

Not so the fancier daylilies. They are “clumpers” that stay in one place. They are easier to dig and move, and can provide color for a few weeks each summer. There are early bloomers, mid-season bloomers, and some that bloom well into the fall. Colors? Clear yellow, rich yellow, various shades of pink, red and even lavender are available. Tall ones with scapes (flower stems) over five feet are available, as are tiny ones with scapes barely 18 inches.

If you want to dig up or divide a daylily, you will need to dig from at least 4 places – thrust a drain spade or transplant spade into the soil at a 45 degree angle on each side, each time trying to get under the center of the clump and tip the spade back to lift it a little. A big clump will give you a good workout. You can divide the clump by slicing through the root mass with a spade or a machete. Even a long serrated knife will do the job. Cutting is much easier than trying to tease apart the roots with a pair of garden forks, which is recommended by some garden authorities. Yes, you may damage a few bits of root when cutting them, but daylilies are invincible.

Daylily blossoms only last a day (hence the name), but most scapes have 6 or more buds that bloom in sequence. I pick scapes with flowers in bloom and put them in a vase. The buds open in sequence for a week or so. So don’t hesitate to use them in a vase. By the way, golden rod is a wildflower (a.k.a weed) that is starting to bloom and does well in a vase. It is unjustly accused of causing hay fever – the real culprit is ragweed (with inconspicuous green flowers), which blooms at the same time.

Other flowers in bloom for me right now in other places on my property include cardinal flower (Lobelia cardinalis) and its cousin great blue lobelia (Lobelia syphilitica) that is showing nice blue spikes. The first needs a moist, sunny site, while the later does fine in hot, dry places (or any sunny spot, really). Black-eyed Susan is in full glory, too. Bee balm (Monarda spp.) is finishing up, and obedient plant (Physostegia virginiana) is just starting to open. Later the fall-bloomers will be along, so I have plenty to look forward to.

So what did I do? I didn’t move a daylily, I dug some annuals that were growing in moist, rich soil and moved them up to the front walkway where the soil is drier. I used my CobraHead weeder to get under a short zinnia (Profusion series) and a big, juicy marigold. They reminded me that I need to water the plants in afternoon sun along the walkway daily – and I’ll give them (and all my potted plants) some liquid fish fertilizer for a mid-summer boost.

You can reach Henry by  e-mail at henry.homeyer@comcast.net or P.O. Box 364, Cornish Flat, NH 03746. His new book is Organic Gardening (not just) in the Northeast, a Hands-On, Month-by-Month Guide.

Creating Beauty on an Urban Lot

in Gardening Guy: Henry Homeyer
labyrinth, lilac, stone

Tom Kelley lives in a big 3-story brick Victorian house just off the town common in Newport, NH that would appeal to the ghoulish characters of the Addams family. But his gardens are full of flowers and vegetables – and are quite a contrast to the building itself, which had been, among other things, home to a veteran’s club and bar.

When Tom bought the place 11 years ago, much of what is now garden was then parking lot. “I didn’t need a huge parking lot, “he said. “I started digging up the asphalt by hand, then brought in an excavator.” Even parts of the property not covered with black top were filled with rubble. “The whole back yard was a big parking lot. When I dug into the ‘soil’ all I found was gravel and chunks of asphalt.”

In order to create a vegetable garden, Tom built wood-sided beds to contain new soil. He now grows tomatoes, beans, squash, greens and much more with great success. “I had a couple of truckloads of soil brought in for my original beds, but I have been adding compost, hay and oak leaves for years. Originally not a thing would grow, not even weeds. We can grow pretty much anything now.

One of the most interesting features of Tom’s garden is his use of stone. He bought some large slabs of granite, and decided that he should use them to make a statement. He hired an excavator and set stones in two groups of three: two vertical stones about 4 feet apart, and a large slab on top of each. They had relatively flat edges, so he was able to make good, steady – and sturdy – structures that look a bit like the Greek letter pi. A modest man, Tom said, “I’m not sure it was completely my idea. I was talking to this guy who was selling stones, and a friend suggested making an arch. So I did. It makes sense here – pi is related to circles (in mathematics), and one is placed at the entrance to a labyrinth (a circle with walking paths).”

Tom’s life partner, Sonia Swierczynski, is a landscaper who lives in Norwich, VT. She has extensive experience with a great variety of plants. Together they have selected and planted a very unusual group of plants. At the front of the house, for example, they planted a hedge of American hornbeam (Carpinus caroliniana). Sonia explained their choice:  ”We wanted to sit on the porch) but didn’t need to totally block out the view of the street. We wanted some diffusion of the view. We didn’t want to shut everything out.” They planted the hornbeam as small plants about 5-feet apart and now, 6 years later, the screen works well. It is 7-feet tall and has filled in nicely. For privacy elsewhere on the property a neighbor put what Sonia calls a “shiny white plastic fence”. She planted red daylilies on their side of it, one called ‘Salieri’ (after the composer) and it is a fabulous contrast to the fence.

Other woody plants that Tom has installed include two kinds of decorative sumac (Rhus typhina), ‘Tiger Eye’ and ‘Lacinata’. Sumacs have extensive root systems that send up suckers, often creating large thickets that are difficult to control. But Tom does not worry about that. “I really liked the form of the sumac and its Oriental look. I really wanted it. I planted it in a place that I thought I could control it by mowing around it, and so far it’s fine,” he said.

Another favorite shrub of Tom and Sonia’s is ‘Limelight’ hydrangea  (Hydrangea paniculata). This is a trademarked variety of the Proven Winners Company. As its name suggests, the panicles (blossoms) are a lime green, though they turn pinkish in the fall. The plants get to be 6-8 feet tall and wide, and are hardy to Zone 3. According to Sonia, “All the hydrangeas are very happy here, and they seem to fit the Victorian nature of the home.”  They grow numerous kinds of lilac, which also are appropriate for the era of the home.

Tom’s lot is perhaps 3 or 4 times larger than a standard city lot, so big perennial flowers work well there. Tree scabiosa (Cephalaria gigantea), for example, grows to be 5-7 feet tall and displays bright yellow 2-inch flowers. It is hardy to Zone 3. They grow a couple of interesting burnets (Saguisorba spp.) including ‘Pink Elephant’ and ‘Pink Brushes’, both big plants that they purchased at Opus Plants in Little Compton, Rhode Island (www.opustopiarium.com). When I looked at the plant list of Opus Plants on-line, I was amazed to see many very hard to find perennials, and plan to visit them soon.

Other big flowers include a fall aster, a variety called ‘Hella Lacey’ and Virginia mallow (Sida hermaphrodita). Virginia mallow grows up to 10 feet tall with big lobed leaves and small white flowers. It is a flower native to Pennsylvania and neighboring states, but is considered endangered.

Tom and Sonia have planted several nice decorative grasses including Siberian Greybeard (Spodiopogon sibericus) and Japanese forest grass (Hakonechloa macra), one of the few grasses I know that will grow in shade.

There really are too many interesting plants in Tom and Sonia’s garden to mention them all. I do know that next June I will visit again to see their peony collection when it’s in bloom – they have a great selection, particularly of white and coral colored ones, which Sonia says “just glow at dusk”.I can’t wait to see them.

Henry Homeyer’s Web site is www.Gardening-guy.com. His new book is Organic Gardening (not just) in the Northeast, a Hands-On, Month-by-Month Guide.

Gardening: A Metaphor for Life

in New England: Quick and Cheap, Seasonal Tip
flower gardening, gardening, wildflowers

Gardening can be considered a metaphor for life. Some gardeners like their gardens –and their lives – simple and predictable. They plant things that they know will succeed and look good: daffodils, daylilies, marigolds, purple cone flowers and such. I grow all those things, but I like to take some risks, too. After all, I could be run over by a bus before the end of the growing season (though my mother did a good job of teaching me to look both ways before crossing). And I want to have the joys of growing special plants that are not necessarily hardy here.

I’m a plant collector and get great joy in growing plants that are outside their climatic zone (or that require special conditions) and seeing them do well. Taking a risk in the garden is different than racing motorcycles or skiing down the north face of Mt. Washington. Yes, I did once spend $75 on a yellow ladyslipper that did not make it through the winter because a dog dug it up, exposing the roots. But that was not personally perilous. I recommend taking some risks in the garden.

My most recent ”risk” was planting a shrub variously called, spicebush, Carolina allspice or sweet bubby. Those names are from my bible of woody plants, Manual of Woody Landscape Plants by Michael Dirr. Sweet bubby – that’s worth planting just for the name! Its Latin name is Calycanthus floridus. Just as plants with botanical names including canadensis indicate northern origins, plants with floridus indicate southern plants. So it may not do well here.

I am a sucker for plants in bloom. I was recently at EC Brown’s nursery in Thetford Hill, VT (www.ecbrownsnursery.com) and saw that new-to-me shrub, spicebush or sweet bubby, in bloom, and had to take one home. The blossoms are a deep dark red, globe-shaped and about 2 inches in diameter. According to Dirr’s book, it is considered hardy to Zone 4, but “-15 or -20 is the breakpoint … flowers occur on short shoots from leaf axils along the entire stem length, i.e. where buds are present; even if shoot tips are winter killed, the potential for good flowering is excellent.” So I am optimistic that it will survive and thrive for me.

After my sister, Ruth Anne Mitchell, died unexpectedly two years ago I planted some plants of dubious hardiness here in her honor. Ruth Anne was a risk taker – she was an intrepid international traveler who thought nothing of hiking a hundred mile through a war zone such as Liberia during the civil war there. While working for an international aid agency she was once captured by teenage rebels carrying automatic weapons and who were high on drugs. They thought she would be scared. Not so. She lectured them, and asked if they would treat their mothers like that. Chagrinned, they brought her to their adult leader who reprimanded them and then let her continue on her way.

Among the plants that I planted in memory of Ruth Anne that did not survive were bunchberry (Cornus canadensis), trailing arbutus (Epigea repens) and that yellow ladyslipper. I also planted 3 blue Himalayan poppies (Meconopsis betonicifolia ), and 2 died that first winter. The third bloomed but died the following winter. Undaunted, I bought 3 more from Cady’s Falls Nursery (www.cadysfallsnursery.com) in Morrisville, VT this year. That one successful poppy, with true sky-blue blossoms, gave me great joy, taught me where to plant it – and gave me the willingness to try again.

Of all the flowers I planted for Ruth Anne, the most successful was the umbrella plant (Darmera peltata). My bible of perennials, Steven Stills’ Manual of Herbaceous Ornamental Plants, lists it as only hardy in Zones 5-7 (minus 20 to zero in the coldest parts of winter). The first year after planting it limped along, but this spring it sent up numerous flower spikes with lovely pink flowers before the leaves appeared. And now those umbrella leaves are a foot across and the clump covers a 4-foot circle.

The key to out-of-zone success is getting the soil and sun requirements right for the plant. Acidity, drainage and exposure to cold winds really do make a difference. Even though the books by Dirr and Stills cost well over $100 for the pair, I think they are worth the investment: they tell you not only cold hardiness, they tell you what kind of soil is needed. I know the world wide web is supposed to have all answers, but I like an authoritative book that I can depend on.

Most nurseries have Dirr’s book on hand, and will let you read it before deciding if you should invest in a woody plant. Dirr’s book is very personal, with his strong feelings expressed, and anecdotes about where he has seen a particular plant growing. I use Stills’ book to tailor the soil for perennials at planting time: he details the fertility needed, so I know if I should add plenty of organic fertilizer, just a little, or none at all.

Take a good look at your own garden. Are you willing to try some new plants? I spent hours this past weekend pulling out the roots of Queen of the Prairie (Filipendula rubra) so that I could plant my new spicebush or ‘sweet bubby’. And if it doesn’t survive? Well, I’ll have a good place to try another interesting plant!

Henry Homeyer lives and gardens in Cornish Flat, NH. You may reach him at henry.homeyer@comcast.net or P.O. box 364, Cornish Flat, NH 03746.

Grow Up! Build a Trellis to Use Your Vertical Spaces

in Gardening Guy: Henry Homeyer
beans, cucumber, gourd, peas, trellis, vegetable gardening

Most of us think we need more garden space. But once we have carved out a garden and removed the grass from the lawn or field, it is often difficult to find more space – or the energy – to expand. But growing plants on vertical supports will help you save space in the vegetable garden.  Bean tripods are well known, but have you thought about a trellis for your cucumbers or gourds? I recently designed and installed 24 wood-sided raised beds for a demonstration vegetable garden at Home Hill Inn, in Plainfield, NH. Each bed is 4-by 8-feet, and although that may sound like a lot of space, it gets used up quickly. I built some trellises to help grow more vegetables and save space.

The first trellis I built for was for cukes. It is an A-frame built using conventional 1- by 4-inch pine lumber. I bought pine boards that had already been sanded and primed, then applied a coat of exterior latex white paint. I used 8 boards, 4 on each half of the A-frame (2 legs and 2 cross pieces on each side). I also bought a pair of inexpensive door hinges and some 1-inch galvanized dry wall screws.

On a flat piece of lawn I began by laying out 2 boards, end to end. I attached the boards with the hinges so that later I could stand up them up to make the legs for an A-frame. I repeated with another 2 boards.  Then I placed the 2 sets of legs 6-feet apart and connected them with cross pieces on what would become the inside of the A-frame. Using a cordless drill, I attached them with 1-inch screws 18 inches from the bottom of the legs of the A-frame and 18 inches from the top.

I set up the A-frame in the garden bed and attached plastic netting I had bought for the job. The netting is 78 inches wide, and has openings 6 inches by 7 inches. To attach the net I used 1-inch screws on the inside of the A-frame; I put the screws in just half way so that the head of the screw could be used to hook the netting on to, pulling it tight. It took a little experimentation to get the spacing right, but worked slick as a bean.

The next trellis was a bit more work. I wanted to build a trellis for gourds that would allow the vines to go up 6 feet or so, then range across cross pieces like a grapes on an arbor, hanging down inside the arbor. I bought 10 pieces of 8-foot long bamboo, each almost an inch and a half in diameter. They make good sturdy poles.

Using a post hole digger I dug 6 holes, each about 16 inches deep. The arbor is a rectangle approximately 6 feet by 3 feet, fitting nicely inside the 4 by 8-ft bed. Each end of the bed had 2 poles about 6 inches from the end and side of the bed, and 2 were place equidistant between the end poles. I held the poles vertical as I added soil back into the hole, checking it for plumb with a small level. I tamped down the soil in the holes with a shovel handle, then mounded the soil up around each pole.

With the 6 pieces in the ground, I added cross pieces (a foot down from the top of the upright poles) on each long side. I attached the bamboo with copper wire I had stripped out of 14-gauge building wire (I was an electrician in an earlier life, and had some in the cellar). I wrapped the wire around the vertical and horizontal pieces and tightened them up with a pair of pliers. Lastly I added 4 cross-pieces on the top to support the vines and allow the gourds to hand down from.

I also built a bean tripod. I went into the woods and cut down 6 maple saplings about 2-inches in diameter at the base; I trimmed each to be 8-feet long. I pushed the poles into the soft earth of the garden bed, and, standing on a step ladder, brought them together and tied them near their tops – where all 3 were touching. I used garden twine, but will go back soon and add some copper wire – I fear the string will rot before the end of summer.

Another way to make a bean trellis is to use four 6-foot (or 8-foot) grade stakes.  These are 1-inch by 1-inch hardwood stakes. Drill a hole 2 inches from the top of each that is big enough to insert a length of metal coat hanger. Cut a 6-inch straight piece of the coat hanger, insert it though the holes, and bend the ends. Then stand it up and spread the legs – two on each side.

Peas are traditionally trellised using chicken wire and posts. My only suggestion is this: put in a post every 4 to 6 feet. That will keep the wire from sagging and flopping as the vines get heavy. You can’t put up a sturdy trellis that spans 8 feet or more between posts, though I drive by gardens that try to.

So if you’re short of garden space, think about getting your veggies up off the ground. In other words, grow up!

Henry’s new book is Organic Gardening (not just) in the Northeast, a Hands-On, Month-by-Month Guide. His Web site is www.Gardening-guy.com.