Category: Outdoors

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 henry.homeyer@comcast.net. 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.

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.

Start with the garlic, have patience with potatoes

Those of us who grow vegetables are faced with many questions each year: Will there be a late frost that will harm our tomatoes and peppers if we plant them on Memorial Day weekend? Is it time to harvest garlic now, since they produced their scapes early this year? When should we harvest broccoli — now, with heads still fairly small, or wait till they get bigger? Will the sun finally prevail and give all our veggies a big boost after all this rain?

We have seen more rain than usual — much more. Even a quick shower results in standing water in the walkways between my mounded raised beds. But in addition to the excess water, plants aren’t getting their usual allotment of sunshine. They need sun — strong, bright sun — to grow and produce fruits and leaves. The lack of sunshine is what is causing smaller veggies, yellowed leaves and later ripening.

Is it time to harvest garlic yet? After the plants send up those curly stems we call “scapes,” it is generally fine to harvest garlic. Traditionally I pull mine in mid to late August. But it’s important to pull them at the right time, not sooner or later than needed.

Here’s what I do: I start by groping my garlic. I slip my hand into the soil and feel how big the bulbs are. I don’t pull them if they’re tiny. But to be on the safe side, I pull a few and look at the skin over the cloves. I want the skins to be strong and tight for good storage. If they are breaking down (due to all the rain), I pull my garlic. If not, I let them keep growing, but check them often.

What about potatoes? My advice is to wait. Yes, you will have some small potatoes as soon as they have blossomed. But I wait much longer than that to harvest mine, as I want big spuds. When leaves start to yellow and die back, then I dig them all. In the meantime, I slip my hand into the soil (without disturbing the plants) and grab a few “new” potatoes for a special treat.

Even though a healthy broccoli plant will produce more food from its side shoots than the main head, some of my plants are small and yellowed from lack of sun. I am pulling the feeble ones and planting a late crop of lettuce by seed in the space.

My Brussels sprouts plants are also much smaller than normal this year. Fortunately, they will continue to grow until the end of October or even later. If we get sunshine soon, they should recover. My normal advice is to cut the tops of the plants off on Labor Day weekend so that the plants don’t keep growing taller but instead send their energy into producing big “sprouts.” This year I’ll be lucky if they have stalks at all. So I will wait and see — and I accept that my harvest might be small or non-existent.

Carrots love the rain and are growing nicely. We thinned them in early July and are keeping them well-weeded. Still, little sunshine means they can’t bulk up as they would in a normal year.

Onions are ready to harvest when their tops flop over. Pull the onions, even if small, and allow them to dry for a week or so in a shady, breezy spot.

One bright spot in the garden this year is celery. I don’t usually grow it, as in the past mine has been tough to chew and a magnet for snails and slugs. This year I planted six plants, and although the stalks are not yet thick, the plants are big and so far have not seemed to attract pests. I ate a stalk, and it is tougher than store-bought. But tasty.

I usually grow celeriac instead of celery, and I did start some from seed indoors. Celeriac is also called celery root and has a big bulb that grows above the soil surface. It keeps in the refrigerator for up to six months, and when added in a soup or stew it has the same celery flavor. This year, with little sun? The bulbs are not showing yet.

All this rain inspired me to grow watercress! I got seeds, and the packet says plant in wet soil, preferably in a shady area. I have that. I only did that recently, but the plants have sprouted and seem happy.

The Cornish Fair is always on the third weekend of August and has competitions for everything: who can throw an ax most accurately, who can produce the best strawberry jam — and much more. For me it is a time to compete in the vegetable and flower categories in the gym of the school. Tomatoes generally are ripe by then, but this year — who knows?

Even though I have been picking off the many yellowed leaves on my tomato plants, they are still far behind their usual selves. Do pick off the yellow leaves — they will only spread fungal disease. But only do so when the leaves are dry — if they ever are!

I heard that a study at Harvard found that people who eat a cup of ice cream every day live longer than those that do not. I couldn’t find this study online, but I have my own theory: People who are happy live longer. If eating ice cream makes you happy, have some! Me? I think the study should have been focused on home-grown tomatoes and potatoes and garlic fresh from the garden. I know they keep me happy — and probably living longer than most!

Featured photo: This vegetable garden is soggy at best. Photo by Henry Homeyer.