Category: Outdoors

Plants that thrive in wet or moist places

I like to say that plants can be as fussy as a 2-year-old facing a plate of overcooked broccoli. Plants know what they want, and will not behave the way you want them to unless you accommodate their wishes. Today let’s look at a few that love wet feet.

First, please understand that plants need oxygen but do not get it from their leaves. No; they get oxygen from their roots. Some plants have evolved ways to get their oxygen despite sitting in water-logged soil while others quickly drown or develop root rot. If you have heavy clay soil that holds water, be sure to pick plants that can tolerate wetness.

I have a small stream running through my property, so much of my land stays quite moist, even in dry summers. In spring I often have standing water between raised beds in the vegetable garden. Yet I have plenty of wonderful flowers that thrive here. Here are a dozen I like, arranged roughly according to bloom time, from early spring to late fall.

1. The drumstick primrose (Primula denticulata) blooms in early spring in hues of blue to red or white. Then comes P. kisoana, which spreads by root in either wet or dry places. Last, starting now, there is the candelabra primrose (P. japonica) which sets out a series of blossoms on an increasingly tall stem over a month of bloom time. All love growing under old apple trees in dappled shade.

2. Forget-me-nots (Myosotis sylvatica). I have these blooming now by the hundred everywhere I look, sun or shade. These lovely low-growing blue (or sometimes pink or white) flowers self-sow bountifully. They prefer rich moist soil and will do well in sun or shade. Because they come back from seeds so easily we let them bloom, then often pull them out like weeds to plant something else.

3. ‘Thalia’ daffodil. Most bulbs require good drainage, but ‘Thalia’ does fine in soggy soil. She is nearly white, and each bulb can produce three flowers at once. She blooms with the forget-me-nots. Order now for fall planting.

4. Globeflower (Trollius spp.). An early summer bloomer, it does best in part sun and moist soil, but will also grow in ordinary garden soil and in full shade. The blossoms are an inch or so across and bright yellow. Blooms in late May to June, but may sometimes re-bloom in the fall.

5. Japanese iris (Iris ensata). These beauties will bloom in standing water or in damp soil. They are like the Siberian iris, but their falls (petals) lay back almost flat. Blues and purples. Early summer.

6. Cardinal flower (Lobelia cardinalis). These flowers are native plants that bloom on 3-foot stalks in fire engine red! I’ve seen them growing on the banks of the Connecticut River, but they do well in moist soil and full sun in my garden. Will tolerate some dryness, but prefer wet. I avoid modern hybrids that are other colors but not as hardy.

7. Swamp milkweed (Asclepias incarnata). Related to ordinary milkweed, this likes moist soil and full sun. Unlike the wild one, this does not send runners out and spread by root. Mine get 3 to 5 feet tall and come in pink or white. Readily available at garden centers.

8. Astilbe (Astilbe spp.) These flowers come in red, pink and white and various heights. They can survive in drier soil in shade, but really love moist, rich soil and full sun. Good cut flower with an almost woody stem.

9. Goldenrod (Solidago spp.). There are many species, some of which spread by root while others do not. It is the very best perennial for supporting pollinators. Mid-summer to fall. ‘Fireworks’ is my favorite.

10. Joe Pye weed (Eutrochium purpureum). This is a native plant that thrives on stream beds and swampy areas that has been domesticated. A cultivar known as ‘Gateway’ is the best but gets to be over 6 feet tall. ‘Baby Joe’ is supposed to be a smaller version, but I haven’t tried it yet. Pollinators love this plant, which blooms in fall with pinky-purple blossoms.

11. Turtlehead (Chelone lyonii). Gorgeous tall stems loaded with pink flowers shaped like helmets – or turtle heads. Will do sun or shade, loves moisture but will grow in ordinary gardens, too. Bumblebees force themselves inside, and seem to growl in there at times. Great cut flower. Fall.

12. ‘Henry Eiler’ rudbeckia. One of the latest flowers I grow. Petals are distinctive: They have space between each one, like missing teeth. Tall, often 6 feet or more. Needs to be staked early, or perhaps cut back in early June to reduce height. Blooms past frost. Full sun, rich moist soil.

If you have a clay-based soil that is sticky when you rub it, wet, between your fingers, you would do well to add compost to the soil before planting any of these lovely flowers. Yes, they like the moisture clay holds, but compost — a shovel or more mixed into the planting hole — will improve their performance.

I’m pleased to report that our new young dog, Rowan, is learning to stay out of garden beds. He’s an 18-month-old golden/Irish setter mix with lots of energy. But so far, he hasn’t dug up any plants.

Featured photo: Pollinators are attracted to Swamp milkweed by color and scent. Photo by Henry Homeyer.

How to rebalance your plant life

Well-intentioned people of the past century imported many handsome plants. Unfortunately, some of them, absent the predators of their homeland, became pests here in America. These “invasives” generally spread quickly by seed and root, and can take over our gardens and adjoining wild places. Many will grow in sun or shade in wet or dry soil — in other words, anywhere!

This is a good time to work on removing as many invasives as you can. You can obtain the entire list online as each state keeps a list of plants that are considered invasive and are prohibited from sale, propagation or transportation. But let’s look at a few that are common and important to remove, no matter where you live.

For me, those include bush honeysuckle (Lonicera spp.), barberry (Berberis thunbergii) and common buckthorn (Rhamnus cathartica). I recently organized a work day on a hiking trail in Cornish that focused on honeysuckle and barberry. We tried to pull these shrubs by hand, but also used a device called a weed wrench for bigger specimens.

Although “weed wrench” is used generically, it was in fact a trade name, but the company has gone out of business. Similar tools can be found under the names “Pullerbear,” “Uprooter” and perhaps others. I have used Weed Wrenches, but not other brands. These are steel tools with sturdy handles and a gripping mouthpiece that bites onto the stem of a shrub up to 2 or 3 inches in diameter, depending on the model. You pull back, and with great leverage you pull out the culprit, roots and all. Some brands come in different sizes.

Many invasive plants are hard to eradicate because if you leave a part of the root in the ground when pulling it out, it will re-sprout. And simply cutting down an invasive tree or shrub usually will often not work: The roots will send up new shoots, and may respond by sending up many, many new shoots.

But don’t be discouraged if you can’t get all the roots out. You are severely setting back the plant you pulled and it will be several years before the plant can produce seeds for birds to distribute elsewhere.

Buckthorn is one of those that responds to cutting by sending up many new plants. Instead of one buckthorn or a clump of buckthorn, you get dozens of buckthorn. But you can kill buckthorn by girdling the trunk. Take a small pruning saw and cut through the bark all the way around the trunk. Don’t cut into the hardwood, just cut the bark. Then go 12 inches higher up, and do it again.

Girdling a buckthorn is a slow death: you are interrupting the flow of sugars from the leaves to the roots, which slowly starve to death. I have done this in winter, and the tree leafed out and seemed normal that spring and the next spring. The third spring it never leafed out — it was dead, and did not send up any new sprouts around the tree.

That said, it is not always easy to girdle buckthorn. They often grow with several trunks that merge near the base and grow tightly together. So a folding saw with a pointed tip is the best way to get into the cluster of stems. Or try to cut the clump twice down low, near the base.

During the recent work day in Cornish, I spoke with someone who explained a theory of invasive plant control that made a lot of sense to me. It was a theory proposed by Dr. Steve Dewey of Utah State University, and was based on the way firefighters approach wildfires. When a fire is raging, sometimes all you can do is try to contain it, and look for places where the wind has sent sparks that are just starting a new fire.

Likewise, when there is a bad infestation of an invasive plant like honeysuckle or barberry on a property, look around for spots where a single small plant is growing. It will be easier to pull than a big one. And within a few years, a small plant will be a big plant producing seeds for birds, wind or water to move to a new location — and to produce a big patch. So put out the glowing ember first, then work on the big fire — or infestation — next.

An easy invasive plant to pull is garlic mustard. This is a biennial weedy plant and might not be thought to be so bad. But its roots produce a toxin that kills beneficial soil fungi that will, in time, reduce tree viability. It can grow in deep shade in our forests. The toxin it produces will eliminate the mycorrhizal fungi that live in symbiotic relationship with our trees, gradually weakening the trees — and killing them. Not only that, garlic mustard inhibits the germination of seeds of many species of native plants, including many spring wildflowers.

As a biennial weed, garlic mustard has two forms. In the first year it produces a low rosette of rounded leaves. The second year it sends up 18- to 36-inch flower spikes with pointy, heart-shaped leaves with jagged edges. The small white flowers have four petals and bloom in clusters about an inch or more in diameter. One plant can produce about 4,000 seeds. And although about 70 percent of the seeds will germinate the next year, some will remain viable in the soil for up to 10 years.

So organize a work party in your town — it’s more fun than taking on invasives on your own. Try to remove any one of the invasives that threaten our woodlands and wetlands. Your grandkids will thank you one day.

Featured photo: Honeysuckle leaves are oval and opposite each other on the stem. Courtesy photo.