Invasives: What are they? What can you do about them?

See a culprit, dig it out

I’m lucky. Unlike many houses built in the 1800s or early 1900s, mine had no invasive plants when I bought it in 1970, probably because it was built as a creamery, or butter factory. Decorative plants were not needed. Most older houses are plagued with plants brought from Asia or Europe by well-meaning people who did not know that, once imported, those handsome plants might not have any predators that could keep them under control. Most of our native insects will not eat foreign plants.

Plants including Japanese knotweed, Asian bittersweet, goutweed, purple loosestrife, yellow pond iris and multiflora roses have thrived in New England, and all are nearly impossible to get rid of, once established. Unfortunately, I now have four of the six mentioned above. But no Japanese knotweed or bittersweet, thankfully (they are two of the worst).

Plants including Japanese knotweed, Asian bittersweet, goutweed, purple loosestrife, yellow pond iris and multiflora roses have thrived in New England, and all are nearly impossible to get rid of, once established. Unfortunately, I now have four of the six mentioned above. But no Japanese knotweed or bittersweet, thankfully (they are two of the worst).

Multiflora rose hips are eaten by birds, but the plants are invasive and should be removed. Photo by Henry Homeyer.

The multiflora rose was introduced from Asia in the 1860s as a vigorous ornamental rose and as a source of rootstock for grafted roses. In the 1930s it was widely introduced as erosion control and alongside highways — a mature planting is so dense it can prevent cars from going over median strips. But the birds liked the rose hips — the seed pods — and it escaped cultivation.

So what am I doing to eliminate it on my property? I am digging it out. Most effective for one- or two-year-old plants, I am using a curved, single-tine hand tool called the CobraHead (www.cobrahead.com) to carefully excavate the roots until I can lift the plant out.

First, I dress appropriately: jeans, long-sleeved shirt, a hat with a brim, and heavy winter leather work gloves. This culprit wants to hurt anyone trying to uproot it. I cut off the branches, just leaving a foot or so to grab onto when pulling it out. Then I loosen the soil and pull weeds around it. The roots radiate outward from the stem like spokes on a bike. I loosen each root and tug gently when they are small enough to remove.

First, I dress appropriately: jeans, long-sleeved shirt, a hat with a brim, and heavy winter leather work gloves. This culprit wants to hurt anyone trying to uproot it. I cut off the branches, just leaving a foot or so to grab onto when pulling it out. Then I loosen the soil and pull weeds around it. The roots radiate outward from the stem like spokes on a bike. I loosen each root and tug gently when they are small enough to remove.

I’ve read that just cutting back the stems to ground level will stimulate the roots to send up new shoots everywhere, causing a bigger problem. There is no easy answer. Invasive plants are always difficult to remove — usually a scrap of root can generate a new plant or several.

Buckthorn is another invasive that is common along streams and at the edges of fields. As with multiflora rose, cutting it down stimulates the roots to send up new shoots. The best way to eliminate it is to starve the roots: Take a pruning saw and cut through the bark and the green layer of cambium beneath that. Go all the way around the trunk, then repeat 6 inches above the first cut, and repeat. This will not kill the tree until the third year, but this slow death will not stimulate the roots to grow. Best done in winter or fall after leaf drop.

Since buckthorn is often multi-stemmed, it can be difficult to use that method. Do it up high enough that you can get your saw in between the stems. But I’ve done it, and it works.

Purple loosestrife is blooming now in swamps and wet places — it is gorgeous but outcompetes many of our native wetland plants that feed pollinators and other animals. Like many invasives, it produces huge numbers of seeds and these seeds don’t all germinate the next spring — many stay dormant for years. I’ve read that multiflora rose seeds can stay viable up to 20 years — a good reason to clear plants out when young.

My approach to purple loosestrife is to dig out new, young plants. I recognize them by their square stem, the leaf shape and the color of the stem, which is often reddish. But for big established plants I just use a curved harvest knife to slice off the foliage once or more than once each summer. This prevents seed production and reduces plant energy.

As regular readers of this column know, I only use organic techniques in the garden. This means no chemicals including herbicides. From what I have read, most herbicides will not kill the invasives mentioned in this article. They will set them back considerably, depending on the age of the plant and the dose of the chemical. But learning to recognize all the invasives is best. And if one appears on your landscape, get rid of it immediately! And remember, persistence is important.

Henry is a lifetime organic gardener living in Cornish, N.H. He presents at garden clubs and libraries around the region, and is the author of four gardening books. Reach him at [email protected].

Featured photo by Henry Homeyer.

Gardening better as we age

Make room for raised beds and homemade cookies

As a Certified Senior Citizen I sometimes wonder if I am too ambitious in my garden. I have about an acre of gardens with 200 or more kinds of flowers and a good-size vegetable garden. These gardens please me greatly, and I visit them daily all year, even in winter. In gardening season I spend considerable time weeding, pruning, mulching and admiring our gardens. I am blessed with a wife who loves to garden and even loves weeding and edging!

Still, I know that my body will not always be able to work as hard as I ask it to now. So what can we do as we get older to make our work easier? First, we can stop buying new plants and creating new garden beds when our current beds are full. That is a hard choice to make, but I do my best to follow that rule.
We can also diminish the size of our gardens. For years I have grown 35 to 50 tomato plants each year. But I will try to drop down to 25 next year, and fewer each year after that. I do love the tomatoes and freeze and dehydrate many each summer for year-round use. But we do have plenty of farm stands growing great veggies, and I could use them more.

Raised beds make gardening easier on us, too. I have one nice deep cedar gardening “trug” that is 6 feet by 2 1/2 feet in size and stands 30 inches tall. I got it from Gardener’s Supply several years ago and it has held up well. I grow mostly kitchen herbs in it, along with a little lettuce and a few hot peppers. It is just steps from the house, while the vegetable garden is downhill and a few hundred steps away. I might get another, or build one.

I recently visited my friend Fred Sullivan, a retired dairy farmer, who lives nearby. His wife of many decades, Shirley, passed away last year; she did most of the vegetable gardening but Fred has taken it on. Some years ago he made Shirley four nice raised beds using landscape timbers. Each is 4 feet by 8 feet and about 20 inches tall. He grows tomatoes, cucumbers, summer squash and some Swiss chard.

I asked Fred about his gardening efforts. He told me that the doctor said he needed to stay active if he wanted to stay healthy. Gardening is a good form of gentle exercise for someone in their 80s, and you get “free” food, too! His best advice: “Be good to your soil, and it will be good to you.”

The raised beds make it easier to work. If you want raised beds, many companies are producing easy-to-assemble beds that are reasonably priced. Although most require quite a bit of soil mix, you can reuse the soil from year to year. I add fresh compost and some slow-release fertilizer each spring to my raised beds.

I recently called my friend Sydney Eddison at her home in Connecticut to talk about gardening as we get older. She is the author of many gardening books and a few nice small books of poetry in recent years. Her book Gardening for a Lifetime: How to Garden Wiser as You Grow Older (Timber Press, 2010) is full of good ideas.

Sydney told me, “Cultivate imperfection.” She said that as we get older we have to accept that our gardens can never be perfect. But she emphasized choosing plants that are reliable under any conditions, and that are low-maintenance plants. I agree.

Daylilies  are easy to grow and require little work. Photo by Henry Homeyer.
Daylilies are easy to grow and require little work. Photo by Henry Homeyer.

Delphinium and peonies, for example, are wonderful plants but most need to be staked and looked after to keep them from flopping or breaking in a heavy rain. I can’t imagine ever getting rid of my peonies, but maybe I don’t need quite so many — I could share a few with younger friends.


A plant that Sydney loves is a sedum called Autumn Joy. She has a dozen or so mature plants, each clump 30 inches wide, and they look good even in winter wearing what she calls “snowy hats.” Daylilies are also wonderful — and a mainstay in her garden. She pointed out that they can bloom for nearly two months if you pick early, mid-season and late-season varieties.

Shrubs are less work to maintain than perennials or annual flowers. Plant them, or have someone plant them, and they will require little — so long as they are not varieties that grow inordinately fast. There are plenty that can go several years without pruning.

One of my favorites is called fothergilla (Fothergilla major). It has nice white bottle-brush blossoms in May and spectacular fall foliage. Mine, after 20 years and very little pruning, is only 5 or 6 feet tall and wide. It’s hardy to Zone 4.
And of course, the easiest plant to grow is lawn grass. Once established it really only requires a weekly mowing. There are plenty of people who are willing to do the mowing for a reasonable fee — and there is little they can do to damage it.
Sydney Eddison gave me good advice: If someone offers to help in the garden, accept! And if no one does offer, try to hire a younger person to help. Offer to teach them about gardening. At the end of the day sit in the garden and drink tea and eat homemade cookies. Both of you will be happy.

Henry is a lifetime organic gardener living in Cornish, N.H. He presents at garden clubs and libraries around the region, and is the author of four gardening books. Reach him at [email protected].

Featured photo by Henry Homeyer.

Cooking and gardening: a marriage made in heaven

Grow basil, eat pesto, let the kids help out

I love to cook, and I love to eat. I got started gardening in the vegetable garden more than 70 years ago, in part, because everyone I knew loved to eat homegrown vegetables — raw in the garden, fresh in the kitchen or cooked for dinner. I’d pull a carrot and rinse it off with a hose — or just wipe off the dirt on my shirt. My mother didn’t care if I ate some fresh (organic) soil with my carrot; she was just glad I liked carrots.

This is the season for pesto, a dish that is heavenly — and simple to make. It has just four basic ingredients: fresh basil, garlic, Romano or Parmesan cheese, olive oil and nuts (and salt and pepper to taste). I used to use pine nuts, but when their price went north of $20 a pound I switched to walnuts. They taste great, too.

We grow a lot of basil each year — 20 plants or more this year. You can grow it in big pots if you don’t have space for a vegetable garden. But this year, if you didn’t grow basil, visit your local farm stand and get a couple of big bunches. For my recipe you will need 2 cups of basil leaves packed down in a 2-cup measure.

If you grew your own basil, hopefully it has not started to bolt — get tall and flower. It will still be usable even if it has, but it is tastier before that happens. Throw away any flowers that have appeared — and snip off flowers on other plants that you are not harvesting today. Blossoming makes the basil a bit bitter.

Wash the basil, then spin dry in a salad spinner if you have one. Remove the leaves from the stems and then pat the leaves dry with a cloth towel. You need enough basil to fill a 2-cup measuring cup with leaves packed down firmly, which is a lot of leaves.

Place leaves in a food processor and add 1/3 to 1/2 cup of roasted walnuts or pine nuts and pulse a few times. I brown the raw nuts in a cast-iron fry pan at medium heat. They brown better if you lightly oil the pan. But be careful: They can easily be burned, so stay right there, stirring constantly until they just brown. I find roasting improves the flavor considerably.

Next, prepare the garlic. You can use a lot or a little, depending on your love of raw garlic. I crush three large or six small cloves of garlic in a garlic press, add to the blender and pulse. I grow my own garlic but you can buy it if you don’t. Har-neck garlic is more flavorful than soft-neck — ask for it at a farm stand, as grocery stores don’t tend to sell it.

Add 1/3 to 1/2 cup of olive oil slowly with the food processor running. Blend the ingredients until the leaves, nuts and garlic are totally blended. Finally add half a cup of grated Parmesan or Romano cheese and pulse until well mixed in. Taste immediately on a toasted baguette or an English muffin. This is heaven.
This has not been a stellar year for tomatoes. All the rain and the paucity of sun has caused many tomatoes to get overwhelmed by fungal diseases. Fortunately, one of my favorites has done well. It’s called Sun Gold. It’s a cherry tomato that is not only delicious but also relatively productive and disease-resistant. I grow a dozen plants each year and each plant gives me 100 tomatoes or more. They grow in clusters of 10 to 20, producing from early to late in the season.

I dehydrate most of my Sun Golds, but also love them fresh in salads, in sandwiches, or cut in half and mixed with pesto. When I put them in a food dryer, I cut them in half with the cut side up. They turn into little nuggets of summer I use all winter in soups and stews.

Pesto is also good with boiled homegrown potatoes. I serve it as a potato salad with fresh tomatoes and a little celery. Yes, after giving up on celery years ago, I grew it this year and it has done well with all the rain. Although in the past it was tough and stringy and attracted slugs, this year it has been a pleasure to grow. I don’t harvest it all at once, but go down to the garden and cut what I need for that day. The stems are much smaller than commercial celery, but I’m glad I grew it.

I think the world would be a better place if every child learned to garden and learned the joy of eating fresh vegetables. You can teach your kids or grandchildren to love gardening the way my family did: Welcome kids to the garden, offer them meaningful jobs that are easy and fun, and never leave them alone to pull weeds. Let little ones ride in a wheelbarrow on top of a pile of weeds you pulled.

One of my first jobs in the garden was to stir the “tea” my Grampy brewed in a wooden barrel full of rain water and hen manure. I stood on an apple crate and stirred it with a long stick. It was a messy job, and a bit stinky, but it seemed like real work to a 3-year-old. Eventually I was allowed to dip out the tea in a metal frozen orange juice can, and give each tomato plant one full can. I’ve been hooked on gardening ever since.

Gardening really should be for everyone, so get your little people to spend time with you in the garden, even if they only search for toads and bugs or push trucks around.


Henry is a lifetime organic gardener living in Cornish, N.H. He presents at garden clubs and libraries around the region, and is the author of four gardening books. Reach him at [email protected].

Featured photo by Henry Homeyer.

Hydrangeas: You always win

Choose the variety that works best for your garden

Unlike the games of chance at our local fair, you always win when you buy a hydrangea. They generally bloom their fool heads off every year, even if you have poor soil and a poor track record in the garden. When I was a boy I noticed that every cemetery had hydrangeas, so I called them cemetery bushes (my parents knew few names of plants). Now is the time they are blooming, so it is time to go to your local, family-owned garden center and buy one — or more than one.

If you want a tall plant with instant curb appeal, buy what is called a hydrangea “standard.” A standard is a shrub that has been grafted onto a tall stem, usually about 5 feet tall. Hydrangeas start out low and often wide, but if you get a standard, you get something that looks a bit like a lollipop — or an instant small tree.

I have six different hydrangeas, each differing in bloom time, color, size of blossom and shape of blossom. Two of mine are standards and are about 25 years old. Each is 15 to 20 feet tall and wide.

The first standard I planted is what’s called a “PeeGee” hydrangea. PeeGee is shortened from the Latin name, Hydrangea paniculata grandiflora (which means large flower head). This is the classic cemetery plant, one that has been around since it was imported from Japan in 1862.

My PeeGee hydrangea has blossoms of various sizes, from 5 inches across to 8 inches or more across. Most blossoms are roughly globular, but some are a bit elongated, especially toward the top of the plant. The panicles are a mixture of fertile and showy infertile florets. The blossoms start out a green-tinged white, transforming to white, then pinkish and finally brown after frost. If you pick the blossoms before frost and put them in a dry vase, they will stay looking pinkish all winter and beyond.

I love my “Pink Diamond” hydrangea; it is also a H. paniculata grandiflora, and lives up to its name even better than a PeeGee. Its uppermost flower panicles can reach 12 inches long and 8 inches wide. The woody stems are thicker and stronger than on most hydrangeas, so they do not flop the way some others do when wet from rain. The pink panicles are a delight to behold.

There is one native hydrangea, called smooth hydrangea (Hydrangea arborescens). It stays small, only 3 to 6 feet tall and wide. It does well in partial shade but is intolerant of dry soils. It will tolerate full sun only if the soil stays moist. ‘Annabelle’ is commonly sold in the nursery trade but I can’t imagine why. Yes, it does have huge panicles, but it has flimsy stems so the panicles droop or flop onto the ground.

According to the Mt. Cuba research station, the best hydrangea for pollinators is the smooth hydrangea called ‘Haas Halo,’ a native one. I planted several for a client one fall and they were immediately consumed by deer. But they came back the following spring and I surrounded them with wire fencing to keep the deer away. In Year 3 they are blooming nicely. The center of each flat flower head is full of small, fertile flowers surrounded by larger white flat, infertile florets.

Another favorite of mine is called ‘Quick Fire.’ Now in Year 5 for me, it is a shrub about 4 feet tall and wide; it is loaded with 4- to 5-inch flower heads. It opens greenish white, then turns white, then pink. The pink color comes on earlier than most others, hence the name. What I like about it is that it keeps a nice mix of white and pink panicles. I am now pruning it yearly to keep it at its current size. It blooms on new wood, so I won’t lose any blossoms if I prune it now or even in the early spring.

Many New England gardeners would like to be able to grow blue hydrangeas, so they buy them and find they really only perform well for one year. A variety called ‘Endless Summer’ came out in the ’90s with much fanfare, claiming it would do as well here as it does in the mid-Atlantic region. But it didn’t do well. Most buds are set the year before, and winter tends to kill them.

Readers often write me asking how to get the numerous blue panicles in years 2, 3 and beyond. I tell them to treat them as expensive annuals. Dig them up and throw them on the compost if they don’t succeed. Instead of Endless Summer, I call them Endless Disappointment. There are now other blue hydrangeas sold, and some may be OK for our climate.

My favorite hydrangea is the climbing hydrangea, H. anomola subspecies petiolaris. Climbing hydrangea is usually sold as a small vine in a one-gallon pot. It takes a long time to get to blooming size — often five or six years. Then it takes off and grows rapidly. The great thing about this vine is that it will bloom in full shade — I have it on the north side of my barn. It will attach to stone or brick surfaces but not wood, though it can climb trees. As it started growing it up my barn I attached it to the barn with a special plastic chain designed for staking young trees. Then later it grew through cracks in the boards and now needs no support — and usually blooms inside my barn! Like all hydrangeas, its flowers stay on and look interesting most of the winter.

So if you like the look of hydrangeas, go get one. I think most are wonderful.

You may email Henry at [email protected]. He is a garden consultant and the author of four gardening books. He lives in Cornish, N.H.

Featured photo: My PeeGee Hydrangea always puts on a good show. Photo by Henry Homeyer.

Big plants, tall plants

Give a flat garden some height with these perennials

If Jack, of Beanstalk fame, were to visit my garden, I think he would be impressed. I’m not sure how tall his beanstalk grew, but I got out my 10-foot tripod Hasegawa pruning ladder and took a picture of a flower blossom while standing on the top step. The flower, a black-eyed susan, stood 111 inches tall on a thick stem that has withstood the wind and rains of recent weeks without any staking. It is truly a Goliath.

But this is no ordinary black-eyed susan. Its Latin name, Rudbeckia maxima, gives you a clue about its inclinations. It wants to be bigger and better than any other in the same genus, or family group. Its common name is large coneflower, which is appropriate as the flower does have a large black cone surrounded by yellow petals. I’ve read that it commonly grows 6 to 8 feet tall, but this year it has exceeded that and may still be growing. The leaves are few but large and blue-green in color. Quite interesting. The leaves are mostly clustered toward the bottom of the stalk.

Large coneflower is not commonly sold in nurseries. But if you find one — or better yet, three — plant it where it can strut its stuff. It does well in full sun and average, moist soil. Perhaps because my soil is above average (it is rich, black and fluffy), my plants are taller than average. A few words of warning: Rudbeckia maxima hates to be moved and can take a couple of years to recover from transplanting, or at least mine did.

Another tall, lanky plant I love is a meadow rue called Thalictrum rochebrunianum ‘Lavender Mist.’ My go-to flower book is Manual of Herbaceous Ornamental Plants by Steven M. Still. This is an 800-page text that tells me most everything I need to know about any flower I want to grow: where a plant will grow best, zone hardiness, flower description, how best utilized, related species and much more. Still’s book says ‘Lavender Mist’ commonly grows 4 to 6 feet tall with delicate lavender sepals, no petals, and “primrose-yellow stamens.’ Like the Rudbeckia mentioned above, mine gets tall, often 8 feet or perhaps more, and has large parts of the stem bare of leaves. The finely cut leaves are on a few side branches along the tall stem. This one does need staking sometimes to keep it erect in rainstorms. It is a splendid cut flower, very dramatic in a tall vase. ‘Lavender Mist’ does well in part shade and rich soil. Half a day of sun is fine.

Some years ago at a garden-design competition in the Loire Valley of France I happened upon a Culver’s root (Veronicastrum virginicum) called ‘Fascination.’ It is a tall plant, 6 to 7 feet tall for me. The flowers are lilac-rose-colored spikes and quite striking. But no one had them for sale in the States until I finally found one for sale at a mom-and-pop roadside corn and tomato stand that also sold marigolds and geraniums. Huh. How did it get there? I don’t know, but I bought it and still have it 20 years later.

‘Fascination’ flops in rainy weather and needs to be surrounded by three strong stakes and a barrier of string. But if I remember to cut back the stems by half in mid to late June, it does not flop and produces many more flower spikes. Instead of one per stem, it produces six or so smaller ones, and a bit later in the summer. Mine is blooming now.

I’ve come to love the common white Culver’s root even better than ‘Fascination.’ It only gets to be 4 feet or so tall but needs no staking. Bees and wasps love it, too.

While visiting a farmer in Ohio I spotted a fascinating big plant called teasel, growing in his corn field. I was told that teasel (Dipsacus spp.) was a horrible weed, and that I was crazy to collect seed from it (though I did anyway). It is biennial with a spiny stalk and leaves and sculptural blossoms that are not like any other I have seen. Hard to describe; see the photo with this article.

Each spring I pull out all but two or three first-year teasel plants so they do not take over my garden. I have three this year, and one is easily 8 feet tall. The flowers are fabulous in an arrangement and can be used dry all winter. Outdoors the stems stand up in wind, snow and ice and are endlessly fascinating to me.

Another favorite tall native plant of mine is called snakeroot, bugbane or black cohosh. Its scientific genus used to be Cimicifuga, but now it has been changed to Actaea. I grow two species, Actaea racemosa and A. ramosa. They bloom starting in August and are a great treat for pollinators, especially bees of all sizes and types. They bloom in alphabetical order, A. racemose first, then A. ramosa. They can have a very strong scent, which I like as much as the bees do.

Snakeroot is a native woodland plant but will do well in full sun or part shade so long as there is plenty of moisture. There are also named cultivars such as ‘Hillside Black Beauty’ that have leaves that are deep purple to almost black and are very striking in the garden. This spring I had ‘Hillside Black Beauty’ growing next to a Rodgersia with big almost orange leaves, and the combination was breathtaking. Later those orange-tinted leaves turn green.

If you garden on a flat area, think about growing some tall perennial plants to give your garden a more interesting look. And mix in some shrubs or small trees to give you height in winter. But that’s an article for another day.

You may email Henry at [email protected]. He is a garden consultant and the author of four gardening books. He lives in Cornish, N.H.

Featured photo: Native Culvers root is delicate looking, but strong. Photo by Henry Homeyer.

Window boxes: something everyone can have

Did you know those little styrofoam-looking beads in potting soil are actually volcanic glass?

You may not have the time and energy to weed and maintain lovely perennial flower beds, or even to grow a few tomatoes, carrots and beans. But if you love flowers you can have a window box or a big pot of flowers on your deck. They can add a punch of color all summer long. And it’s not too late to start now.

Before you get too excited about planting flowers at this time of year, visit your local garden center, farm stand or other source for plants. Some places sell out by the end of June. Others keep nice annual flowers coming all summer long. And some are already selling chrysanthemums and fall asters, which will provide nice color for the weeks ahead.

I recently visited Caroline Storrs of Cornish, New Hampshire, to look at her window boxes as she told me hers were in their full glory now. Her husband, Peter, is a retired building contractor who built her window boxes for her. He used a synthetic material made from PVC plastic for the window boxes. That material is more expensive than wood but does not rot, warp or splinter. There are several brands available, and from what I can see synthetic wood costs from $10 to $15 per square foot of material.

Caroline explained that their window boxes were made wider and deeper than most commercially made window boxes. She said the more space there is available to the plant roots, the bigger the plants will grow, whether in pots or window boxes. She also pointed out that window boxes should be mounted so that there is an air space behind the boxes to prevent rotting of the wood siding or clapboards.

The potting mix is also important. Caroline’s boxes run all the way across the garage beneath upstairs windows — for perhaps 30 feet. They are about 10 inches deep and 8 inches across, which means that a huge amount of potting mix is needed to fill them all. She makes her own potting mix instead of buying it in bags, which would be more expensive.

Caroline makes a planting mix of one third peat moss, one third perlite and one third compost (which she gets by the pickup truck load), mixing it in a big wheelbarrow. She also adds a slow-release fertilizer as the basic ingredients of the mix do not provide enough of the needed nutrients to sustain the plants all summer.

Not all annuals do well with high-nitrogen mixes, as they can grow tall but delay flowering. Plants grown for their foliage do well with lots of nitrogen but may need pinching back to control size. If you do not use a slow-release fertilizer, you may need to use a liquid fertilizer every week or two to keep your plants happy.

Perlite is the white fluffy stuff in potting mixes that looks like bits of Styrofoam but is actually volcanic glass that is superheated until it pops like popcorn. It helps keep a planting mix from compacting. And although it does retain some water in its nooks and crannies, it does not absorb water.

Vermiculite is another material used in some potting mixes, and this does absorb water and holds it much better than perlite. It holds on to minerals, too, which perlite does not do. That’s important if you use liquid fertilizers, which can wash away quickly.

I’ve read that too much vermiculite can lead to a constantly wet mix, leading to root rot. From my experience a mix of perlite and vermiculite is good, particularly in dry summers. Perhaps one part vermiculite and two parts perlite would be good. Vermiculite is mica that has been heated to a high temperature. Both products have a neutral pH.

In each window box Caroline planted geraniums, chartreuse-colored sweet potato vines and coleus, a foliage plant. Coleus now comes in both sun and shade varieties, and some that will grow in either sun or shade. It does not appear to bloom but has multi-colored leaves that can be striking. The sweet potato vine hangs down and out of the box, while the coleus grows up and the geraniums add bold color in the middle of each box. She repeated the pattern all the way across the front of the garage to great effect.

Watering is important. Because her plants are so big and leafy, they require lots of water. Caroline told me that she waters every day — which means they do not travel in the summer. Peter told me that he drilled lots of holes in the bottom of the boxes to prevent the soil mix from staying soggy in rainy times. The holes can leak soil mix, so it is important to put landscape fabric or screen in the bottom.

I built a cedar window box more than 20 years ago and although it is starting to show its age it is still sturdy. I did not treat it with anything. I recently made another similar box also using 6-inch-wide cedar boards.

My new planting box is made for morning glories. I have a blank wall to which I attached a nice wood trellis and wanted to break up the tedium of the wall. And although 6-inch boards do not provide the depth of Caroline’s boxes, the vines have already reached the top of the 6-foot trellis.

Gardening really is for everybody, even those with limited time, energy and space. Grow a few flowers in a window box or pot and they will reward you with their beauty — and that of the butterflies they attract.

Featured photo: This small cedar window box is fine for a few morning glories. Photo by Henry Homeyer.

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