Weed report for 2016.
Lovely photo above of crocus blooming on March 11, when you would think that the garden is weed-free, at least visibly so, but just look in the upper righthand corner. Creeping Charlie. In March. At least it isn’t growing.
This is the 2nd year of my 7-year weed eradication project. In 7 years, if I weed long enough and hard enough, my garden will be weed-free. Oh, sure.
As I have written before, this idea came to me as I read various authors who wrote about weed-free gardens, usually someone else’s garden, not their own. In Odell Shepard’s The Heart of Thoreau’s Journals, Thoreau praises his friend Minot for having no weed seeds in the soil of his farm. In Second Nature, Michael Pollan writes that his grandfather had a weed-free garden. In My Weeds, Sara Stein knows someone in Maine who has a weed-free garden. In The Illustrated Garden Book, Vita Sackville-West writes that she prefers gardens to be weedless and tidy. In a 1971 letter to Organic Gardening magazine, Mrs. Magnus Olson writes that when she bends down to pull 1 weed, she stays down until she has pulled 10. In this way, she achieves a weed-free garden. Barbara Damrosch, in The Garden Primer, and Eliot Coleman, in The New Organic Gardener, have strategies for achieving a weed-free garden in 7 years.
But Damrosch also warns that 1 year of backsliding will mean starting over on the 7-year eradication project. Coleman specifies 3 strategies. Don’t bring buried weed seed to the surface. Get rid of weeds while they are small. Don’t let weeds go to seed.
In Weeds: in Defense of Nature’s Most Unloved Plants, Richard Mabey doesn’t hold out hope for weed-free gardens. He points out that weeds fill up bare spots. That’s their job. It’s what they do. Weeds have a purpose as first succession plants in disturbed areas. So if you want to control weeds in the garden, don’t leave bare spots.
So much excellent advice and encouragement. In this the 2nd year of my weed eradication project, I realize that weed eradication is not a linear march toward a successful outcome. So much depends on variations in rainfall and temps. Chickweed was a minor nuisance in the spring of 2015, probably because the bitter cold of March kept it from making a good start. This spring, after a mild winter, the chickweed came on like gangbusters. Also the other winter annuals, like purple deadnettle and hairy bittercress. In the photo left above, taken on April 5, purple deadnettle can be seen intermingled with lush chickweed. In the photo right above, taken on April 7, hairy bittercress is lifting its siliques above a small patch of chickweed.
In addition to the mild winter, there is another reason for the abundance of chickweed this spring. Bare spots. In the fall of 2015, I gave the blueberries a dressing of compost and peat moss. Although the blueberry patch is covered in wood chips, close up around the bushes were bare spots of rich nutrients. As can be seen in the photo above, taken on April 7, chickweed liked that environment just fine.
Also in the fall of 2015, hoping to make the serendipity corner even more serendipitous, I removed some large pieces of slate and tore up some black plastic mulch that was buried under a thin layer of soil. More bare spots. After reading Mabey’s Weeds, I’m not surprised about the chickweed. Under the blueberries, I created a rich environment for the chickweed seed that was probably lurking in the compost. In the serendipity corner, I unearthed weed seed lying in wait under the slate and plastic mulch. The photo above of those cute little chickweed plants in the serendipity corner was taken on June 20–2 months later than the chickweed under the blueberries. An excellent article on the Penn State Extension website reports that chickweed seeds ripening in warm weather are not dormant and can sprout immediately. Chickweed seeds ripening in cold weather must wait for spring when alternating temperatures break their dormancy. So temps are a factor for when spring chickweed gets its start. The article also mentions that chickweed seeds below 1/4 inch of soil will remain dormant, so seeds need to be very near the surface to germinate.
As I’ve written in previous posts, early this spring I gave chickweed a big bad 10 in my weed hierarchy, meaning that I had to drop everything and eradicate chickweed whenever I saw it in the garden. This quickly became onerous because there was just too much chickweed. So, I grew philosophical, having just read Mabey’s Weeds, and thought chickweed might make a good ground cover under the blueberry bushes. Plus, robins depend on chickweed seed as an early spring food, so the chickweed in the serendipity corner would be a welcome treat for the early robins in my garden. Life is good.
However, after the chickweed grew huge and started producing seeds–see the seed pods in photo above, taken April 8–I changed my opinion of chickweed again. There was too much to ever hope to eradicate this year, but I had to work on control hereafter. I guess that’s a 5 in my weed hierarchy. Sort of like creeping Charlie. I pulled masses of chickweed. At least when it gets huge, it pulls out in huge bunches. Unfortunately, all these lush greens cannot go into the compost pile since they are covered with seed pods. They have to be sent curbside for municipal pickup. What a waste.
In the fall, I worked at scrubbing the little chickweeds out with a collinear hoe. So, perhaps I made some progress against chickweed for next year. Now that I recognize those cute little plants instantaneously, it’s easier to focus in on getting rid of them in a timely fashion. But they will be back next spring. I have no doubt about that.
Purple deadnettle (Lamium purpureum), seen above, which I had previous identified as henbit (Lamium amplexicaule), was not a huge weed problem, maybe a 3 in my weed hierarchy, and has the redeeming quality of providing an early spring nectaring source for honeybees. Its fibrous roots make it easy to pull in moist soil. I’m looking forward to next spring when I can observe and photograph its growth in order to figure out if I have both purple deadnettle and henbit in my garden, or if it’s all purple deadnettle. Each year is different, of course. Next year may be the year that purple deadnettle, or henbit, takes over my garden and becomes a huge nuisance.
According to an article on the University of Kentucky Ag website, the lower leaves of both purple deadnettle and henbit have long petioles, or stalks. However, henbit’s upper leaves are sessile, or stalkless, while purple deadnettle’s upper leaves have short petioles. According to Weeds of the Northeast, both weeds have lobed leaves, but the upper leaves of henbit appear more lobed while purple deadnettle’s upper leaves are more triangular. Looking at the photo above, the upper leaves probably have short petioles, or stalks, thus identifying the weed as a purple deadnettle. And the upper leaves are more triangular.
At this point, you may be thinking, what difference does it make. A weed is a weed. This is true, but the challenge of identifying weeds keeps me going on my 7-year weeding project. Without the company I keep by reading various authors and bloggers who are also interested in weeds, I likely would not put in the time.
Because purple deadnettles and henbit are winter annuals, their cute little seedlings, as seen above in December 4 photos, are present throughout the winter, albeit easily overlooked. A cold, sunny day in December would be a good time to pull a few. The 2 seedlings above both have square stems. The seedling to the left was found in among some creeping juniper alongside the driveway. The seedling on the right was found in an unused cold frame without the plexiglass top on it. They are different, aren’t they.
I pulled some of each to get a closer look. Again, on the left, the seedling found among the creeping juniper by the driveway. On the right, in the unused cold frame. Could the left one be henbit and the right one be purple deadnettle. Or are they some different weed entirely. All I can do is keep watching the seedlings in each area, particularly as they mature next spring.
As can be seen above, purple deadnettle, or henbit as the case may be, doesn’t look a bit like creeping Charlie. At top of the photo above, taken on December 2, is a fairly compact purple deadnettle/henbit seedling pulled from alongside the driveway. At bottom is the sinuous, rooted stem of creeping Charlie, carefully extracted from the blueberry patch. The leaves are somewhat similar, rounded and lobed, but there the similarities end.
As described in a previous post, I decided on a day in April to wage war on hairy bittercress (Cardamine hirsuta), another winter annual. I was frustrated with the likes of creeping Charlie and chickweed, which I couldn’t eradicate, and decided to take revenge on a weed I thought could be eradicated. Hairy bittercress was it. I put on some gloves, grabbed a 5-gallon bucket, and set out to pull all the hairy bittercress in my garden. Because I thought I could, of course. This is my treatment for weeds that I’ve ranked a 10 in my weed hierarchy. Singleminded focus on that weed, with absolutely no diversions into other garden chores, until the weed is eradicated for that day to the best of my ability. I managed to fill a trash can with hairy bittercress and send it curbside for municipal pickup.
Today, December 4, I looked for hairy bittercress seedlings. I didn’t find any. Or maybe I’m just not identifying them. So we will see if hairy bittercress comes back to my garden next spring, or if I did indeed eradicate it.
A final winter annual, corn speedwell (Veronica arvensis), barely made a showing. It can be seen in the above photo taken April 22 in a dry, sunny strip between a wooden deck and a slate walkway. We’ll see if corn speedwell has ceased to be a weed of my garden, or not.
Mugwort (Artemisia vulgaris) made its customary showing in the raspberry patch in April, but the plants seemed to be individual plants without extensive rhizomes, so perhaps my mugwort diligence in summer of 2015 paid some dividends. Of course, mugwort can’t be left alone or it will start its spreading habit once again. Mugwort is always a 10 in my weed hierarchy. Dense patches of 3′ high mugwort with huge seed pods in August in the local parks are enough to keep me motivated about eradicating mugwort in my garden. Or trying to.
Here is mugwort coming up through cracks in the driveway in December. The weed whacker controls mugwort plants in the driveway, but doesn’t eradicate them.
Wild mustard (Sinapis arvensis) and garlic mustard (Allaria petiolata) both made brief appearances in April by the metal fence. Next spring I plan to watch them for awhile before pulling them. I want to see how menacing their siliques, which all mustard plants have, look as they mature. They reproduce by seed, which are jettisoned from the siliques in due time. Each plant produces 1200 seeds or so. The seeds can persist in the soil for many years. All this from Weeds of the Northeast. Perhaps, like dandelions, they will persist in my garden even if I pull them all every year.
Hairy galinsoga (Galinsoga ciliata) and Pennsylvania smartweed (Polygonum pensylvanicum) made their expected appearances in July and stayed around until frost killed them. Both reproduce by seeds. Lots of seeds. Galinsoga, seen above in photos taken in October, is sometimes called quickweed because its seeds germinate as they are falling to the ground, or so the story goes. It is quite tender and will turn black with the first frost, like basil.
Pennsylvania smartweed, shown above on October 19, is not so easily done in by frost as galinsoga. Its foliage turns brownish-red after the first frost and the plants linger, but they will not persist through the winter. This information is from Weeds of the Northeast, my goto weed identification book.
Both galinsoga and smartweed did not seem so pervasively overwhelming in their sheer quantity this summer, so maybe I’m making progress. They are first-succession weeds for sure. They monopolize any bare ground available. So it’s important to cover bare spots either with other plants or with mulch. Last summer, we distributed 2 big truckloads of wood chips around the garden, probably 20 cubic yards of wood chips. The 1st truckload was from our own garden, mostly from the old maple tree that died and was cut down. We covered the old maple tree area with mulch after the roots were ground out. Wood chips were also laid down deep under birch trees and pine trees and around the blueberry and raspberry patches. A layer of wood chips was put down in the wildflower corner before I planted wildflowers. I’m grateful to say that I was the helper in this labor-intensive endeavor, not the main muscle behind the wheelbarrow.
But galinsoga and smartweed will always find nooks and crannies to grow in. I’m pretty sure about that.
I have a fun story about broadleaf plaintains (Plantago major) this summer. At least as fun as can be expected when weeding is the topic. Plantains are one of the big summer uglies and require the intensive 10 treatment in my weed hierarchy, if it’s possible. This summer, July and August were so dry, and the soil in the area that we mow and call a lawn was so compacted, that digging plantains to get the roots out was impossible. In the photo above, taken June 20, a plantain seedpod can be seen among clover. Believe me, the seedpods only got bigger and badder as the summer progressed.
Since the plantain plants could not be pulled out of the dry, compacted soil, we compromised and picked the seedpods. I left cans and buckets around the garden where the seedpods could be easily thrown away. Whenever we went out for a stroll around the garden or a break from computer work, we would pull off the seedpods and throw them in the nearest can or bucket. Of course the seedpods came back, a little smaller, but we pulled them again. The process was fairly painless and didn’t require thought or preparation. After the rains came, I went back to pulling the plantain plants with the dandelion/plantain tool and disposing of them in trashcans at curbside for municipal pickup. In this way, we may have reduced the available plantain seed for next year. Only time will tell.
We also tried a new experiment with the omnipresent creeping Charlie, seen above under a blueberry bush in an October 19 photo.
Creeping Charlie is the major weed in the area we mow and call a lawn. So, during a rainy spell in October, we used the weed whacker to take the Charlie down to ground level. Then we spread lime and top soil over the area and planted tall fescue and white clover seed. We encircled the area with benches and boards, mostly to discourage canine traffic. After the rains, we continued to sprinkle the area several times a day. As can be seen in the photo above, taken October 19, the tall fescue and white clover are up and flourishing. Of course, the roots of the Charlie are still there, but how will they compete with the grass and clover. I can only hope this is the beginning of a winning strategy against creeping Charlie in the area we mow and call a lawn.
Evidently, crabgrass (Digitaria sanguinalis) and prostrate knotweed (Polygonum avoculare) were too ugly to photograph this summer, since I took no photos of them. I pulled crabgrass religiously however, although often only after seed pods were in evidence, so it will be back. Prostrate knotweed grew once again along the pathways and by the gate in bare, compacted soil. It’s very difficult to pull. I sprayed vinegar on it once again, but that’s only a temporary fix–also ugly since the plants turn brown until little stems reappear from the roots. Both of these uglies are summer annuals that reproduce by seed. They will be back next summer.
Tumble pigweed (Amaranthus albus) also reproduces by seed. A few tumble pigweed plants raised their ugly heads by the garden gate. Although they have a taproot, they were fairly easy to pull. I hope I disposed of them in time.
Japanese knotweed (Polygonum cuspidatum) will always send up its shoots around the shed. It spreads by rhizomes from the park behind my garden. All I can do is pull those little shoots the minute I see them. This is a really big bad 10 in my weed hierarchy. I often pour vinegar down the little hole left after pulling a shoot. I don’t know that it helps since the shoots always reappear. Control is my only option here.
Last year, I counted blue violets (Viola papilionacea) and Asiatic dayflowers (Commelina communis) as weeds. This year I decided to call them wildflowers instead, which means that they are desirable but must be controlled.
Blue violets are larval food plants for great spangled fritillary (Speyeria cybele) butterflies. The eggs are laid not on the blue violets but in nearby wood chips or leaf litter. Knowing this changed my attitude toward the blue violets. Now I’m hoping to nurture them in the wildflower corner without letting them take over the garden completely. If more great spangled fritillaries in my garden are the result, it will all be worthwhile.
Here is a photo taken September 18 of the blue violets in the wildflower corner. Great spangled fritillaries overwinter as larva. I haven’t found any, but I hope some of those caterpillars are overwintering in the wildflower corner.
Asiatic dayflowers can become a problem if they are allowed to colonize, but as single plants they have appealing little blue flowers and lush green leaves and stems. When I cleared some pachysandra to plant a small sweetbay magnolia (Magnolia virginiana), Asiatic dayflowers cropped up almost immediately in the bare space around the magnolia tree. I can only think that the previous owner planted pachysandra to get rid of Asiatic dayflowers, which it did. When the pachysandra was gone, the dayflowers came back. They were dormant for at least 20 years. Wow.
Above is a December 7 photo of the sweetbay magnolia in its little wood chip area, which will revert to pachysandra or Asiatic dayflowers in the spring if I am not vigilant about eradicating the pachysandra and keeping the dayflowers under control.
I have come to consider pachysandra a weed. I hate it and am trying to clear it a little at a time, but it’s not easy because it comes back from roots left in the ground, and also because other weeds or wildflowers, like the dayflowers, will fill in any bare space, so it’s always a struggle, even with a wood chip mulch.
Believe it or not, I think I’ve now accounted for the major weeds of 2016. Here is a summary of my weed strategies, garnered from other weeders’ experiences and insights, as well as from my own weed experience.
Don’t bring buried weed seed to the surface.
Get rid of weeds while they are small.
Don’t let weeds go to seed.
Cover bare ground with desirable plants or mulch.
Control wildflowers so they don’t become weeds in the garden.
Of course, I always remember Mrs. Olson’s advice to pull 10 weeds whenever I bend over to pull 1 weed. And of course it goes without saying that I don’t use herbicides. Indiscriminately killing all broadleaf plants including clovers and wildflowers while polluting the environment doesn’t seem like a good weed strategy to me.
Weeds will still occupy my time and thoughts in 2017, the 3rd year of my 7-year weed eradication program. I hope I’m making progress.