This has been a banner year for the weeds in our yard as the excessive rain has not only nurtured their growth but also kept me out of the yard on too many days when I could have been staying on top of weeding. Some weeds submit easily to pulling while others will put up quite a fight. Bull thistle, Cirsium vulgare, has ridiculously sharp spinose teeth on its stems and leaves so that any attempt to grab its rosette of leaves and pull results in a bit of pain. Appropriately also known as spear thistle, bull thistle’s basal rosette can grow up to 3 feet in diameter with a fat taproot that further aids in the difficulty of hand-pulling it. It reproduces from seed so if you can manage to extract it before it sets seeds from its purplish, globe-shaped flower in its second year then you can break the cycle. It is supposedly not only edible but tasty once the spinose teeth are removed, a fact which must have been discovered by an extremely hungry person or else someone wearing chain mail gloves.

Bull thistle, Cirsium vulgare crop

Bittersweet nightshade, Solanum dulcamara, is easy enough to pull out when it’s young, before it becomes semi-woody. Its threat lies in the fact that it flowers from May to September, each star-shaped purple flower producing a bright red berry and each berry containing up to 30 seeds. As the berries are eaten by birds these seeds are dispersed far and wide. Once it starts to grow this perennial vine sends out suckering roots and prostrate stems that can climb to 30 feet. This is a plant that loves the deep shade of the understory, where it’s unusual arrow-shaped, 3-lobed leaves thrive.  A member of the Connecticut Invasive Plant list, bittersweet nightshade is prohibited from sale, movement, or distribution by state statute.

Common yellow woodsorrel, Oxalis stricta, and its cousin, creeping woodsorrel, Oxalis corniculata, appear everywhere in our yard: under trees, in the lawn, and in the flower and vegetable beds. With its trifoliate leaves it bears a resemblance to clover except that its blossoms are delicate 5-petaled yellow flowers. All parts of woodsorrel are edible and its high in vitamin C but eating large quantities can inhibit the body’s absorption of calcium. These creeping weeds pull out easily.

Common blue violet, Viola papilionacea, may be considered a weed or a wildflower, depending on where it is growing in your yard. I don’t mind that it runs rampant beneath several Norway spruce trees in our yard. The almost full shade area is a great habitat for this low-growing perennial which prefers a shady, moist area. These pervasive plants tend to grow in basal clumps of heart-shaped, toothed leaves that have violet flowers in May and June. Supposedly the common blue violet will adapt to being repeatedly mown in a lawn by growing smaller leaves on shorter stems. The clumps are easy enough to pull out by hand but you may not get the entire underground rhizome by which it easily spreads.

Another ‘weed’ that I don’t mind is Lady’s thumb, Persicaria masculosa. Although it is a member of the same family as knotweed, Polygonaceae, Lady’s thumb is a delicate summer annual. The tiniest pink flowers bloom on raceme-like spikes that may reach up to 2 feet high but are generally around 12 inches. Unfortunately, each of those tiny flowers becomes a seed that will germinate the following spring. I only recently found out why the common name for this plant is Lady’s thumb. A close-up look at the leaf will reveal a triangle-shaped smudge midway down the leaf which is the lady’s ‘thumbprint’.

But the weeds that I dislike the most are the seedlings of trees and shrubs. I find that they are the most pervasive and simply ridiculously difficult to eradicate. First is autumn olive, Elaeagnus umbellata, another card-carrying member of the Connecticut Invasive Plant Working Group. Unlike perennial weeds, the seedlings of woody plants are not so easily disturbed. Even cutting back autumn olive as soon as growth is seen, which I admit to having done, is a bad idea as this may just promote more growth. Late September and October is the best time to treat with an herbicide applied to freshly cut stems, not to the foliage as is commonly done.

 

Chinese wisteria, Wisteria sinensis, although not listed as an invasive species in Connecticut, can become an issue in a home landscape. I take full responsibility for this being in our yard though as I planted a wisteria many years ago, wanting those delicate drooping purple flowers to grace our deck, long before I knew about its potential. I never knew that you could purchase a ‘bad’ plant from a reputable nursery. The main plant sends out suckers from its base all season but I just break them off. It’s the seedlings that establish themselves in other areas before I notice that they are there that are an issue. Some control can be achieved but cutting the plant back over the entire season or even removing it entirely. However, small pieces of the roots left in the ground cam send up new growth. Foliar or cut stump applications of an herbicide in the spring or summer when the plant is actively growing is recommended.

And finally to my least favorite weed, the bane of our landscape. White mulberry, Morus alba. Also known as Russian mulberry (even though it is native to China) or silkworm mulberry, it was introduced to North America by the British who thought that they could use it to establish a silkworm industry. In fact, the Virginia assembly passed acts between 1656 and 1669 to penalize the non-planting of mulberry and offered bounties for its production and for silkworm cocoons. By the 1830s Connecticut was the epicenter of raw silk production in the United States with Mansfield producing raw silk with a value of $60,000 in 1834 and Windham County producing 5 tons of silk cocoons annually. It became a cottage industry where many families produced 5 to 50 pounds a year. The Cheney Silk Mills in Manchester also played a large part in this field. (Silkworm image, Cheney Brothers, circa 1900, Connecticut Historical Society)

Silkworms, Cheney Brothers, manchester, circa 1900, CT Historical Society

The rearing of silkworms was very labor-intensive, I won’t go into the process here but you should check it out at Connecticut’s Mulberry Craze. Why isn’t this still an important industry in Connecticut? As it so often is, the answer is money. Over-inflation by speculators devalued the market and then this was followed by a harsh winter which was the demise of many trees. The final blow was the development of man-made fabrics.  But enough white mulberry trees survived to become popular ornamental specimens that have naturalized into our urban landscapes. (Image by T. Davis Snydor, the Ohio State University, Bugwood.org)

T. Davis Sydnor, The Ohio State University, Bugwood.org

The deciduous leaves of white mulberry come in a variety of shapes and can be un-lobed or divided into 3 to 5 lobes, all on the same branch. It has edible purple drupes that can be messy and stain decks and pavement.

White mulberry can grow to 50 feet but because it is often cut down as a seedling it ends up looking more shrub-like. If I’m lucky I catch it shortly after it has come up in which case the roots will easily come up. I cut it down continually where it is unwanted and cut stumps can be painted with a non-selective herbicide. White mulberry will survive in any kind of soil and any kind of drainage and tolerates conditions from flooding to near-drought. It prefers full sun, in which case the leaves will be more pronouncedly lobed than those that grow in shade. I have to give it credit for its tenacity. But not in my backyard, please.

Susan Pelton

UConn Home & Garden Education Center