An Explosion of Spring Weeds

Ever heard of a painter whose spouse couldn't get him to paint the house? That's a bit like my backyard. While I've been doing plant work elsewhere this spring, my own backyard was quietly, stealthily taken over by an extraordinary array of spring weeds. The day of reckoning, or more likely several weeks of reckoning, has finally arrived. 

First step, photograph them and write about them, on the chance that others might too find themselves wading through a backyard full of weeds and wonder what they all are. Click on a photo to make it larger.

This one, the most ridiculously successful, is purple deadnettle. It's in the mint family, which you can tell by its square stem, but unlike many other mints, it relies on seeds to spread, rather than underground rhizomes.

Here's more purple deadnettle, with a foreground of ground ivy. Ground ivy has other names: creeping Charlie, and gill over the ground. It spreads vegetatively above ground, across lawns, into garden beds. It could be charming if it weren't so aggressive. The same can be said for mock strawberry.

Here's the ground ivy mixed in with some white clover at the bottom of the photo. The white clover hasn't been a problem, but in some situations, it too can become a sprawling mass.

Ground ivy looks like a wave here, rising out of the lawn and swamping the stonecrop Sedums. I really like the dandelions, until they go to seed, then not so much. If the soil is soft, gather all the basal leaves in your hand and give a slow, steady pull. Feed the leaves to your guinea pigs. Do people still have guinea pigs as pets?

By now, you'll recognize the ground ivy at the bottom of the photo, the purple dead nettle in the middle. Equally prevalent is hairy bittercress, which is the now brown plant in the upper left. A gardener feels a sense of defeat when, having delayed too long in pulling the hairy bittercress, its seeds come flying up at your face. It feels like mockery, the plant having successfully completed its life cycle and populated the ground with seeds for yet another year.

On the upper right in the photo are a few garlic mustards. They are edible, so I pull them, eat the seedheads, then toss the plant where it won't reroot. My yard would be full of them, too, if they were as stealthy and quick to generate seeds as the bittercress. Being larger than bittercress, garlic mustard is more satisfying to pull, and since it is slower to mature its seeds, we can go through a period of procrastination and still pull it in time. Garlic mustard is a biennial, meaning it grows some basal leaves the first year, building up energy in the root, then launches a flowering stalk the next spring. If not pulled, it will go to seed, then turn yellow and die in mid-summer, its work done. 

That's a different approach from many of these spring weeds--hairy bittercress, purple deadnettle, common chickweed, henbit, etc.--which sprout from their seeds in the fall, overwinter in the vegetative state, then get a quick start in the spring, blooming and setting seed before distracted people like me can pull them. 

At the top of this photo is hairy bittercress before it turns brown. On the left is Canada thistle, which has taken over many a garden bed in Princeton, spreading underground, popping up all over. I keep it at bay but have not been organized or persistent enough to fully get rid of it. 

At the bottom there are violet leaves. 

I'd like to say that the violets are less aggressive. They integrate into the lawn rather than taking it over, sprinkling attractive blooms hither and yon, and the leaves and flowers are good in salads, or steamed. But even they started being way too pushy in the flower beds a couple years ago, prompting a major weeding out. If salad makings weren't so easy to get in the local store, we'd be eating violet leaves, feeling just fine and with more balanced gardens to show for it.

Happy to say that I have no lesser celandine in my yard--the most problematic of the spring weeds, given its capacity to take over and then spread into the neighbor's yard and nature preserves. There was one in the yard a few years ago, but one medicinal spritz of herbicide was all it took to nip it in the bud. The leaves are reminiscent of violets, but are less curled, lighter green, and more leathery in appearance.

Mugwort, down there at the bottom, is a tough customer that has taken over many gardens, raingardens, and fields. Recurrent pulling has limited it to one place in my garden, but it spreads to form monocultures along the gas pipeline right of way along the Princeton ridge. Above and left in the photo is a kind of horsetail that has inculcated itself into one of the flower beds, probably planted decades ago by a previous owner.

I remember Veronica (speedwell) from my field botany days. It has an interesting bi-colored flower, and in our Michigan yard it had seemed harmless enough. When it showed up in our Princeton yard a few years ago, I let it grow here, but, perhaps due to a sunnier yard and abundant rains, 

it exploded this year and became, like so many problems in the world, too much of a good thing.

Chickweed hasn't been much of a problem. 

Curly dock is easy to undercut with a shovel. 

You see that little triplet of leaflets sticking out at the bottom? That's wild strawberry. I thought it would be great to have wild strawberries in the garden--native, tasty little berry. But they spread like crazy and I happened upon only one berry over the years.

Another weed that's here and there and can easily be pulled from wet ground is rough avens. To its left in the photo is a native weed called willow herb. Both of these look like they might generate attractive flowers, but don't quite generate enough show to be considered ornamental.

Wood sorrel, bottom of the photo, is a common greenhouse weed, but not much of an issue in a garden. Its leaves look somewhat like clover, but are tangy with the taste of oxalic acid.

The green leaves towards the top of the photo are jewelweed, a native annual that can be rambunctious, but which I appreciate for its tubular orange flowers that attract hummingbirds.

Most of these weeds originally hitchhiked to America from other continents. Finding early on as a gardener that most of my labors involved saving the intended plants from these overly enthusiastic weeds set the groundwork for understanding the problem of invasive species in nature preserves.

The reader may by now have concluded that my garden is largely a battleground where a distracted gardener is little match for weeds that grow 24/7. But there are areas where balance is easier to maintain, where celandine poppies, redbuds and dogwoods start a pleasing progression of flowers that continues through the spring. 

Princeton's Fuel Tank Raingarden Wannabe

Why would a plant lover be drawn to this desolate scene of concrete and asphalt? Because there's a raingarden behind that fence, or at least a raingarden wannabe, and that means I'm seeing not what is, which is pretty drab, but what could be, which is a dynamic, jubilant planting of native wildflowers, grasses and shrubs filling that skinny raingarden squeezed between the sidewalk and the town's fuel tank. The fuel tank was for awhile serving double duty, fueling town vehicles while its appearance fueled controversy in the neighborhood. A fine rain garden planting could go a long way towards healing the discontent, in my humble, totally plant-biased opinion.

The first good news is that the fresh layer of asphalt there appears to be appropriately tilted to shed its runoff towards the raingarden. What is a raingarden, after all, if the rain that falls on the surrounding topography doesn't flow towards it?

For some reason the raingarden hasn't been planted yet, so the plants have gone ahead and started planting themselves. It's looking a little sparse thus far. Or you could say that the plants are social distancing.

Whenever I see plants trying to colonize bare dirt, I think of people who live in an emotionally impoverished situation. Back when I was in that predicament, I was drawn to places like this. Weeds trying to grow in parched ground were my friends and fellow travelers. Maybe that's why I can remember plant names when most people struggle, because the plants aren't just variations on green. They touch something deeper in me.

This late-flowering thoroughwort is a keeper--a native wildflower whose name is unlikely to flow smoothly from many tongues. It grows like a weed, and often in weedy places, like abandoned fields or roadsides, but can sometimes achieve great elegance of form when it becomes covered with plates of white flowers in late summer. It shows up early, but blooms late. Thus the name.

Here are the leaves of mugwort, which adds no color and spreads aggressively underground, taking over neglected raingardens over time. It's a force for monoculture and monotony that must be countered early and often.

Smaller scale weeds are clustered here, close to the ground, with dandelion on the lower right, a mock strawberry in the middle, and one 3-seeded mercury on the left. When I see one or two mock strawberries like this, I'm also seeing five years hence when it will have spread to coat the ground in an unattractive and inedible way. That increases the motivation to be proactive and pull it out now, before the task becomes overwhelming. This ability to imagine the future, learned in a garden, is directly translatable to global issues like climate change, where the job only becomes harder the longer one waits. 

Lots of homeowners puzzle over what to do with hundreds of oak seedlings in their yards, when everyone is telling them we need to plant more trees. Most tree species don't need help. They plant themselves, often in inconvenient places, like this raingarden.

Playing the editor, I'd say this nonnative red clover is a keeper as well, but pull the tall sweet clover at the other end of the raingarden. Sweet clover can be kind of pretty in a gangly way, but it is one of those midwestern and western weeds that appear to be expanding eastward, like teasel, Queen Anne's Lace, knapweed, and wooly mullein. Having lived in the midwest, I've seen how they can start to take over.

Leaping into the void in plants and action a couple months ago, I pushed some "live stakes" of buttonbush into the bottom of the raingarden. Despite the poor, hardened soil, they have sprouted. Here again, I'm seeing not so much the less than impressive seedling but instead the 8 foot high shrub it could become if it's allowed to get well established.

Just up Witherspoon Street, at the Princeton Recreation Dept. headquarters next to the community pool, is a demonstration of how gardens can look if there's someone knowledgeable taking care of them year after year. There's some serious tending going on here. Even the scarily aggressive variegated goutweed (whitish leaves on the left), which tends to take over gardens, is neatly contained in a discreet clump. These gardens owe their existence and beauty

to Vikki, whose job description in the Recreation Department probably has nothing to do with plants. From what I've seen over the years, it's clear that Vikki is one of the few people in town who is hard-wired to have a soft spot for public gardening, like Polly Burlingham with her hanging baskets downtown, and the various school gardeners, and like Dorothy Mullen was until she left our world earlier this year. I'd say that all it takes is love, and from that all things follow--vision, knowledge, persistence, strategic timing.

Maybe the sad, forsaken raingarden wannabe just a block away will somehow become loved ground. It's got "good bones"--sun, inputs of moisture. Good things could happen.

Cardboard Quells the Chaos--Renovating a Garden Bed

When plants aren't "playing well with others," sometimes one has to lay down the law. That's what happened in an area of the garden that got away from us. While we were off living our lives, Lizard's Tail, sunflower, and a common goldenrod were quietly sending their rhizomes out in all directions. Ground ivy and mock strawberry were overwhelmingly undertaking relentless stoloniferous expansions. And the once endearing, highly edible blue violets were pushing their way into every nook and cranny.

Some nature writers congratulate themselves on their tolerance for all living things, but that tolerant pose somehow doesn't extend to species that threaten people, e.g. COVID-19. A lot of the love gardeners feel for the plant world is expressed, ironically, by killing some plants that are threatening others. I may love red oaks, and can see that even poison ivy has an ecological role, but that doesn't mean I'm going to let a thousand seedlings take over a garden bed.

In extreme cases, where the desired and undesired become hopelessly entwined, or a garden path disappears in a sea of "way-too-much-of-a-good-thing" overgrowth, it's time to bring in the cardboard.

Yes, cardboard. Given all the negative forces in the world, cardboard stands out as a beneficent presence, rivaling that of chickens, or perhaps peanut butter, outstanding in its inborn capacity to do good with very little downside. Occupying a niche somewhere between wood and paper, cardboard can take myriad shapes to serve myriad purposes, whether keeping stuff together in a basement or rising into high art at a museum or on a stage.

In a garden, cardboard serves in a sprawled state, depriving weeds of sunlight, and creating a barrier that's strong and lasting enough that weeds can't push through. Some people use landscape fabric, but over time soil begins accumulating over the fabric, weeds grow on top, and the buried fabric then becomes a nuisance that needs to be pulled out and thrown away. Cardboard serves as a barrier for a season or two as it slowly decomposes, leaving no trace.

Here's the legacy of neglect, with path stones retrieved from the chaos,

and a tangle of way too aggressive sunflowers and violets. All are beautiful in their way, but hard to keep in balance with everything else.

Before laying down the cardboard, a few beebalms and lizards tail were retrieved from the mess with the intention of planting them elsewhere.

A variety of sizes of cardboard are useful. I put a few desired plants in--the sort that don't spread but instead grow in bunches--like ironweed, boneset, hibiscus, culver's root, tall meadow rue, cutleaf coneflower--then surround them with overlapping pieces of cardboard. More plants can be put in along the seams or by punching a hole in the cardboard. The walkway stones were put back in place, and other stones used to keep the cardboard in place until we can cover it with mulch.

Here, for instance, we're using cardboard as a base for a walkway around the "Veblen Circle" of native plants at the botanical garden next to the Herrontown Woods parking lot. A stone border is laid along one edge of the cardboard, and chips are placed on top, completely disguising the cardboard. The result is a weed-free path for a year or two. That's a whole lot easier than pulling each individual weed.

Deceptive Weeds

This time of year, you may see some plants rising in the garden that look like they have potential. Something about their form makes you hesitate to peg them as weeds and pull them out. Maybe, you think, it's better to wait and see if all that growth yields a substantial flower. Here are some weeds that have fooled me into a wait-and-see at some point in the past.

Pilewort has a thick stem and strong vertical intent. It will give you pause because it looks like it's headed somewhere, which, it turns out, is mostly up. All that vertical ambition climaxes in a gangly jumble of small flowers that attract pollinators but lack color. The name comes from the white seedheads that look like cottony stuffing for a mattress. If left to scatter, they will give rise to many more plants to be pulled the next June.

Pilewort - Erechtites hieracifolia - Aster family

Willow herb has a nice form, but can get weedy in wet soil, and the flowers are too small to create a visual effect.

Northern Willow Herb

Epilobium glandulosum

A member of the borage family, this plant, too, has an attractive form that looks like it could generate an attractive flower. If you leave it in, you'll end up instead with a bunch of stickers to pick off your clothes. Appropriately enough, it's called stickweed.

Stickseed
Hackelia virginiana
Borage family (Boraginaceae)

Mugwort has a nice resiny odor to the crushed leaves, and looks like it could grow an attractive flower, but doesn't. Instead, its capacity to spread underground to form dense masses makes it a threat to any garden. The cardboard box in the photo will be laid flat to smother the weeds.

There are Bidens with very showy, sunflower-like yellow flowers that bloom along Quaker Road later in the summer. And then there is the Bidens species that somehow made it into my garden, which produces flowers that lack any show at all. We had the showy species flourishing along a bike trail in Durham, NC. Gorgeous, but it grew so enthusiastically that it started obscuring the trail. Though it reaches great size, Bidens is an annual and can be easily pulled.

Even though I know that lambs quarters doesn't make showy flowers, the plant fools me each year into thinking I'll get around to eating its tasty and nutritious leaves. Generally, I forget, but this year my younger daughter used some in a red lentil soup that was delicious. An annual, lambs quarters can be abundant one year, hard to find the next. Like pigweed, it can get enormous in abandoned plantings.

When pulling weeds, pull low and slow, so the roots come out. Weeding teaches the gardener to be strategic. Humans tend to have little time, while the weed is dedicated to growing and spreading 24/7. Best to weed when the soil is soft, to get the roots, and before the weeds go to seed. To keep them from rerooting, best to drop them where the roots won't touch the ground, and where the sun can dry them out.

Weeding a Rain Garden in June

The curb at the Westminster Choir College parking lot looks like a serpent, dipping low to allow runoff to enter a constructed raingarden where pollutants and trash are filtered out, and the water feeds the plants. The raingarden does a lot of environmental work, so maybe someone could do some work to take care of it? Care of installed raingardens is not something most landscape companies do, and so the task falls to a local volunteer with the required knowledge, or the raingarden fills with weeds and gets mowed down and becomes yet more boring lawn.

In this scene, blue vervain grows in the spaces left by the expanding redbud and tupelo trees.

Switchgrass makes billowy mounds.

The raingarden is doing better than it was a couple years ago when I adopted it, but there are still weeds to easily undercut with a shovel, like wild lettuce and curly dock.

And bindweed to pull that would otherwise grow over everything.

The mugwort was proactively dug out last year, but a few are still popping up. The pink in the photo is red clover, a non-invasive exotic that gets left in the mix.

A bedstraw species smothered an area ten feet across before being pulled up. This may be the native stickywilly (Galium aparine), but was being way too aggressive for the setting.

Here's the bindweed growing up and over a late-flowering thoroughwort that's worth protecting from aggression for its late summer flowers.

Not shown here is the crown vetch, another aggressive grow-over-everything weed.

White clover and dandelions would require more time to weed than this volunteer has.

One nice discovery, not remembered from previous years, is a swamp milkweed, which would have little chance of growing if the aggressive weeds weren't controlled.

Random Spring Weed Identification

Most gardeners will have encountered a small weed this spring with tiny white flowers that have already bloomed. The thick circle of basal leaves suggests it's the non-native Hairy Bittercress, rather than the native Pennsylvania Bittercress.

The plants produce seeds that will fly up at you as you try to pull the plants out. That's how you know you have, yet again, procrastinated too long before weeding them out of the garden. I was moved to pull many of them from my yard in time this year, but only because I was expecting company. There's a lesson in there somewhere.

Another non-native is Veronica (probably V. persica), which forms low clumps in the lawn with many tiny blue flowers. Lovely flowers when viewed up close. It shows up in lawns, but I haven't seen it being as aggressive as some weeds. Update, spring, 2022: Veronica is spreading like crazy across my lawn. As with so many yard weeds, this is way too much of a good thing.

Japanese knotweed pops up like asparagus from among last year's dried stalks. It is a common non-native invasive along rivers, forming dense, exclusionary clones. This one's part of a patch just upstream of Pettoranello Pond.

An increasingly common weed in lawns and gardens is lesser celandine, mentioned in a previous post.

It spreads quickly to form dense masses that are pretty for a couple weeks but don't leave much room for other wildflowers to grow. If wildlife don't like the taste of it, and as far as I know none of them do, they have to seek food elsewhere. This is a big reason why even a beautiful exotic flower can be a concern, because it doesn't support a foodchain of diverse organisms, i.e.  is slowly making the landscape inedible.

.

This is an aquatic plant at Pettoranello Gardens that I first noticed showing up last year, most likely called pond water starwort (Callitriche sp.).

From Europe and northern Africa, it's considered an exotic invasive in Connecticut.

It might be mistaken for the native duckweed, but a clump of duckweed consists of thousands of individual plants, each with a pair of leaves.

(Thanks to Chris Doyle for help with identification)

SOME OTHER POSTS ON WEEDS:

An Explosion of Spring Weeds

Weeds That Launch an Underground Insurgency