Weeds


Large crabgrass (Digitaria sanguinal)

Crabgrass is the bane of many people seeking a ‘nice’ lawn. It is a weedy grass which will out-compete desirable grass species and take over in a short time. Crabgrass has a wider blade, is lighter in color and grows faster than the lawn making it obviously stand out as a weed. Its seed germinates earlier and at lower ground temperatures than other desirable turfgrasses giving it a jump in growing time.

The best defense against all weeds of lawns is to maintain a healthy stand of turfgrass by having soil pH and nutrients at the correct levels. Healthy soil supports healthy grass. Lawns mowed at a height of three inches or taller has less crabgrass and other weeds as the soil it shaded, excluding light from reaching the seeds which initiates germination. Crabgrass is an annual growing new plants from seed each year. None of last year’s crabgrass lived through the winter.

Low cut grass invaded by crabgrass.

 

 

Chemical control against crabgrass is applying a pre-emergent herbicide. They attack the newly produced tissue from the germinating seed up to young plants with a couple of leaves. Pre-emergent herbicides have no effect on seeds in the soil that do not break dormancy and start to grow, only the seeds which start to grow. Timing of application is before the crabgrass seeds start to germinate when to the soil temperatures are 50 to 55 degrees Fahrenheit. This is the same time the forsythia is just past its full bloom stage and starting to but out some green leaves.  The germination period ends when the lilacs begin to bloom. Just remember to apply after forsythia and before lilac flowers. Forsythia and lilac make a great plant indicator for applying the pre-emergent herbicide against crabgrass.

Forsythia bush

Forsythia bush.

lilac .psu.edu-lilac

Lilac, photo (psu.edu/lilac)

There are several different pre-emergent herbicide active ingredients with varying rates of how long they last in the soil. Products containing pendimethalin will last about four months out in the environment. Other active ingredients, dithiopyr, benefin+trifluralin, prodiamine, will last a shorter period of time. Read the labels for the residual rate for each formulation’s time it will last. Most pre-emergent herbicides will stop all seeds from continuing to grow after germinating. This means you will not be able to plant desirable grass seed after applying it. Products containing Siduron are the only pre-emergent herbicide that will allow cool season grass seeds to grow while eliminating crabgrass.

-Carol Quish

 

The common blue violet (Viola sororia), also known as common meadow violet, purple violet, woolly blue violet, or wood violet, is a native perennial plant found throughout eastern North America. Some references give woolly blue violet (a variety with fuzzy leaves) its own species name but the most common status seems to be a single species with high variability. This little spring wildflower blooms from April through June and occurs naturally in moist meadows, woodland edges and along roads. It prefers moist, somewhat shady sites but once established it can thrive in dry and less favorable conditions and is often a problematic weed in turfgrass and landscapes.

J. Allen photo

J. Allen photo

At 3-8 inches tall, it is low growing with leaves and flowers on petioles originating from the root, not from a stem. Reproduction is via rhizomes and seed, both allowing spread and persistence in lawns and gardens. The most prevalent flower color is purple to blue but occasionally flowers may be pale purple, gray or white.

Flowers consist of five petals with two upper, two lateral and one lower petal. The lower petal has striking stripes that lead from its edge to the center of the flower and this design helps guide pollinators to the nectar within.   The color and scent of the flowers aid in attracting pollinators as well. Violets flower early in the season when pollinator activity may not be reliable so they produce a second type, a cleistogamous flower that appears lower to the ground and often later in the season. These are self-pollinating

Photo: Rob Routledge, Sault College, Bugwood.org

Photo: Rob Routledge, Sault College, Bugwood.org

Seed capsule.  Photo credit: http://en.wikipedia.org/wiki/Viola_(plant)

Seed capsule. Photo credit: http://en.wikipedia.org/wiki/Viola_(plant)

Historically, violets have been used for both food and medicine. Medicinal uses have included treatment of the common cold, headache, cough, sore throat and constipation. Nutritionally, a half cup of violet leaves are reported to contain as much vitamin C as three oranges. Both flowers and leaves are edible. Some violet species have a sweeter flavor and a stronger aroma that make them a nice garnish or addition to sweet dishes while others have a mild pea-like flavor and blend well in savory recipes. Some recipes for using violets are available on the American Violet Society website, including this one for crystallized viola.

CAUTIONS:

  • Never use plants for food unless you are 100% certain that you’ve identified the plant correctly.
  • African violets are NOT related to these plants and are NOT edible.
  • Do not use plants that may have been treated with any kind of chemicals/pesticides including those in lawns, roadsides, etc. if history of the site is unknown.

There is a beautiful ‘language of flowers’ in which a particular flower can carry a special meaning or message. The message associated with a particular flower, which may be specific to color, can vary by region or reference. In North America (according to one reference), the violet means modesty and blue violets in particular can mean watchfulness or faithfulness or may send the message ‘I’ll always be true”. More on the language of flowers and a list of many for North America can be found here.

So far, I’ve just mentioned in passing the fact that perennial violets can become a weed problem in turfgrass and landscapes. If you’re interested in what to do about this plant as a weed, there is great information here from Purdue University.

  1. Allen

 

The showy white or light pink, funnel-shaped flowers of the wild morning glory are abundant along roadsides right now. Maybe, like me, you think to yourself as you’re driving around or on a walk, “I’d like to find out what kind of wildflower or plant that is when I get home” and then later forget about it until you see them again.   So, here to help you with at least one of those flowers, I will provide some information on this pretty native wildflower.

The scientific name is Calystegia sepium.  This comes from the Greek kalu “cup” and stegos “a covering” for the genus name Calystegia and sepium means “of hedges” or “of fences”, because of its climbing tendencies.   In addition to wild morning glory, the plant has some fun and interesting common names including old man’s cap, devil’s guts, bride’s gown, white witches’ hat, Rutland beauty, great bindweed and hedge bindweed.    It is a member of the Convolvulaceae, the morning glory family.

This plant is easy to grow and becomes aggressive at times, covering other plant to the point of killing them.  The vine of the wild morning glory twines around slender stems and objects in a counter-clockwise direction.  Darwin described this plant and patiently (I’m guessing) observed that the plant made two revolutions around another stem (size unspecified) every 1 hour and 42 minutes.  He even noted that completing the semi-circle moving away from the sun took 14 minutes longer than the semi-circle of growth moving toward the sun!

Wild morning glory vine growing over a shrubby plant.  Note the distinctive shape of the leaves. J. Allen photo.

Wild morning glory vine growing over a shrubby plant. Note the distinctive shape of the leaves. J. Allen photo.

Some identifying characteristics:  This herbaceous perennial vine grows up to about 3-10 feet in length and branches freely.  It can form tangled masses on structures and other plants or just freely grow along the ground.  Stems are reported as being either hairless or with hairs.  Young vines may have a red tinge to them.  Leaves are shaped like an arrowhead.  They, like the stems, may or may not have hairs on both the upper and lower surfaces.  The tips are pointed.  The leaves are about 2-4” long.  The base of the leaf is distinctly angular with lobes described as resembling dog’s ears in shape.   Flowers are produced singly and have fused white to light pink petals, forming a funnel shape.  Two large green bracts are present on the base of the flower, both in the bud stage and after the flower opens (visible at base of buds in the photo below).  Individual flowers are only open for one day.  Flowers are present in the northeast from mid-May through September.  Two to four seeds are produced in a capsule.  The dark brown seeds are shaped like little orange segments and can survive for up to 30 years.

Flower of the wild morning glory, Calystegia sepium.

Flower of the wild morning glory, Calystegia sepium.

This plant can be confused with other vines, especially field bindweed (Convolvulus arvensis).  Field bindweed has smaller leaves that have a more rounded tip and bases that are rounded or pointed, but not cut off squarely like the ‘dog ears’ of wild morning glory.

While this plant is attractive, it is aggressive enough to be designated a noxious weed in some states.  It is not listed as noxious in Connecticut.  If you have a problem with the vines and need advice on how to get rid of it, the best method is just hand pulling.  This will require persistence because new plants can grow from the rhizomes which tend to be shallow but can reach 10 feet in length.  And, as mentioned above, seed can survive for up to 30 years.   A study (done in a greenhouse) reported in 1974 that wild morning glory had allelopathic tendencies, meaning that exudates from the roots inhibited the growth of other plants.   This would help explain its ability to ‘take over’.   Another, more labor intensive tactic that is reported to kill the vines is to unwind them and rewind around the stem or support in the opposite (clockwise) direction.

A number of insects visit the flowers for nectar and act as pollinators.  These include long-tongued bees such as bumblebees, little carpenter bees, mallow bee, squash & gourd bee, and the morning glory bee.  Day-flying sphinx moths may visit the flowers in the morning.  One reference mentions Syrphid flies as well.  It is thought that the flowers on the same vine are self infertile.  In a study in Japan, it was found that all the pollen was gone by noon.  The leaves are eaten by the caterpillar of the common plume moth (Emmelina monodictyla) and by several tortoise beetles.  This plant is not favored by mammalian herbivores.  The bobwhite and ring-necked pheasant eat the seeds some.

The stalks and shoots are reported to be edible and to have a sweet taste after being washed and steamed.  They should not be eaten in large quantities because of a purgative effect. Wild morning glory has been used in traditional medicines as a diuretic.   The seeds are toxic in large quantities and the roots are somewhat toxic to pigs but the pigs eat them anyway without having serious trouble.

By J Allen

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Stellaria media  is the Latin name for Chickweed. It is a common weed if left unchecked, will form a dense mat of foliage, and produce mass quantities of seed. In the late winter and very early spring, it is an always green presence in my vegetable garden.  Just about the time the snow has melted enough for me to be able to open the garden gate, I can see these weed plants struggling to grow as much I am yearning to yank them out! It is a hard time of year for us die-hard gardeners, not being able to work the soil while invaders are using our sacred garden areas for their own benefit and the detriment of ours. Still I find hopefulness in the sight of the cold tolerant chickweed; it brings me hope this will still grow and there is a gardening season ahead, even if I have to wait awhile until the earth warms.

photo by Carol Quish

photo by Carol Quish

 

Chickweed is an annual plant, preferring the cool season and dies out during the heat of the summer. Hand pulling and cultivating with a hoe is pretty effortless as the root system is small and shallow. The plants pull out easily. All parts of the chickweed plant are edible. Raw in salads it reportedly tastes like corn silk. Cooked, it tastes a bit like spinach.

-Carol Quish

Image

Queen Anne’s lace or wild carrot (Daucus carota) is native to parts of Europe and Asia and is naturalized in North America and Australia.  It is a biennial in the family Apiaceae.  Domestic carrots are cultivars bred from its subspecies D. carota ssp. sativus.   Being a biennial, it grows a leafy mound of green fern-like foliage the first season and then produces flowers the second year.  Flowers are produced from June through August. The tiny white flowers are borne in flat to slightly rounded clusters called umbels.   Before they’re fully open, the flowers may have a pink to reddish caste.  In some umbels, there is a single dark red flower in the center.  This is said to be a droplet of blood where Queen Anne pricked her finger while making the lace.  The function of the red flower is thought to be an attractant for insects.

The root of the wild carrot is edible when it is young but becomes woody and unpalatable as it matures.  As early as 2000 years ago the crushed seeds were used as a contraceptive.  Research has somewhat supported this; in studies with mice wild carrot was found to disrupt the egg implantation process.  It is not recommended here to use wild carrot for this purpose!

Wild carrot has a poisonous look-alike plant, poison or water hemlock, so it should never be consumed  unless it is absolutely certain that it has been identified correctly.   The leaves of Queen Anne’s lace can cause irritation known as phytophotodermatitis.  When the sap from the leaves gets on the skin and it is then exposed to sunlight, a rash may develop.   This plant is considered a noxious weed by the USDA because of this and because it is a pest in pastures, displacing desirable native plants.

Queen Anne’s lace is also a beneficial plant because it can help attract insect parasites and predators of pest insects to the garden.  Beneficial wasps, ant lions and green lacewings either feed on the nectar or pollen of the flowers or are attracted to aphids on the flowers.

Many animals use the wild carrot plant as a source of food or shelter.  Some that use it as a food source include the eastern black swallowtail butterfly, honeybee, green stinkbug, differential grasshopper, golden northern bumblebee and green lacewing.  Many animals use it for shelter including the eastern black swallowtail, aphids, dog ticks, Chinese mantid, American goldfinch, black and yellow argiope, eastern bluebird, green stinkbug, eastern mole, differential grasshopper, northern mockingbird, common grackle, green lacewing and chiggers.   Other plants commonly found growing with wild carrot include goldenrod, milkweed, pokeweed, smooth crabgrass, red clover, English plantain, devil’s beggar-tick, spotted Joe-pye weed, lamb’s quarters, common ragweed, jimsonweed, black-eyed Susan, Kentucky bluegrass, wild strawberry, and common mullein.

J. Allen

Spring has finally made her appearance after a very long winter. Shockingly warm days this past week has made leaves seem to explode in the landscape. Along with the flush of green in the lawns and bursting leaves on the trees and perennials, is the return of two unwanted pests: the lily leaf beetle and garlic mustard.

The lily leaf beetle larva from last year spends the winter in the soil as a pupa changing into the adult beetle form sometime during the unseen underground respite. As the soil warms and the lilies poke up from the soil in the spring, the lily leaf now adult beetle comes out also. The beetles will begin to feed on lily leaves. They will also mate after which the  female will lay eggs on the under side of the lily leaf. Eggs will hatch in a few days into a cream colored hump-backed grub. The grub will begin to feed on the lily leaves. Here is the gross part; when the grub poops, it will pile the excrement on its back. This is a protective measure so birds and other predators will not want to eat it! It seems to work as I find no predators eating the poop covered immature in my garden. Once the grub has grown large over a 16 to 24 day period, they drop to the ground to pupate. Adults emerge 16 to 22 days later, feeding on mostly lilies and sometimes on frittilaria, lily of the valley and a few other plants. Lily leaf beetles will only lay eggs on true lilies and larva will only feed on true lilies also. Daylilies are not true lilies and not a host for larva or adult lily leaf beetles. Control measure are handpicking all life stages or spray neem oil on the larva.

LilyLeaf Beetle, (umaine.edu)

Larva covered in excrement, (cornell.edu)

Garlic mustard is a very prolific and invasive weed. It is blooming now, showing off its many white flowers, producing incredible amounts of seed later in the season.  It is believed that the European settlers brought the original plants or seeds with them here as a food or medicinal source in the 1600’s. It has become nuisance along roadsides and un-mowed areas. Garlic mustard is a biennial, producing low rosettes of leaves the first year and shooting up two to four feet with a flower stalk the second year, then the plant dies leaving a multitude of new seed to germinate in subsequent years. What makes this plant particularly obnoxious is its ability to stop growth of virtually all surrounding plants growing nearby, displacing the native plants and diverse food sources for many animals. Control can be had by continued hand removal or herbicides. Glyphosate is the recommended chemical herbicide.

– Carol Quish

Garlic mustard, dnr.we.gov

First year garlic mustard plant

Garlic mustard

Dandelions do not deserve the bad image many people (especially those maintaining lawns) have of them.  In addition to being very attractive, they have many uses, including companion planting, being a food source and also they can be used to make wine.   The common dandelion, Taraxacum officinale, is native to Eurasia but is now well-established world-wide.  There are quite a few other species in this genus and they belong in the family Asteraceae.  Members of this family have composite flowers, meaning that each “flower” is actually made up of many tiny ray flowers clustered together.  Dandelions grow well on a wide range of soil types, are not pH sensitive, and can tolerate light shade. 

Dandelions are herbaceous perennial plants with a deep taproot and a low-growing rosette growth form.  The hairless leaves have deeply toothed edges.  These “teeth” give the dandelion its common name, which is derived from the French “dent de lion” which means lion’s teeth.  Other common names for the dandelion are related to its diuretic effect and include ‘pissenlit’ in modern French or ‘pissabeds’ in English.  In German it is called ‘pusteblume’ which means ‘blowing flower’ because of children’s habit of blowing on the seed heads when they mature.

  Photos from Wikipedia.org

Over the centuries, many medicinal benefits have been attributed to the dandelion.  In addition to diuretic properties, it has historically been used for liver and gall bladder ailments, gout, and chronic joint and skin ailments.  The latex or milky sap has been used for removal of corns and warts.  These are historical reports and are not endorsed in this article. 

 All parts of the dandelion plant are edible, although the flavor can be bitter.  It is a nice green for salads.  The leaves are best when young or after the first frost in the fall.   They can also be sautéed with other vegetables.  Dandelion greens are highly nutritious with even more vitamins and minerals than greens like spinach.  They are high in potassium which helps compensate for potassium loss resulting from the diuretic effect of the plant. The taproot is also edible and can be used cooked with other vegetables in soups or stir fries.  Mix with sweeter vegetables like carrots or peas to compliment its bitter flavor.  Even the flowers are edible.  They can be eaten raw or cooked, fried in fritters, pickled or used to make tea or wine.  A wine recipe is included below from this website: http://oldfashionedliving.com/dandelion.html

 Dr. Lehman’s Dandelion Wine

4 quarts dandelion flowers
4 quarts boiling water
4 pounds sugar
1 lemon
2 oranges

Pour boiling water over the flowers. Let stand 24 hours. Than boil 20 minutes. Put in the rind of the lemon and orange in when boiling. Strain through colander. Add the pulp of the lemon and orange sliced in when it is lukewarm. Add a tablespoon of yeast and let stand a week. Than strain it through cheesecloth and put it up. Keep a month before using. If you put it in a jar, do not tighten all at once(the lid)(Don’t seal too soon or you will over-pressure the bottles)

~This is from Doc Lehman of Mountville,Pennsylvania

More dandelion recipes are available at:  Dandelion Recipes by Wildman Steve  Brill.

 Photos: Wikipedia.org

Dandelions also provide an important early spring food source for honeybees.  According to one source, they were imported into the Midwestern states from Europe to provide a good food source for imported European honeybees.   They are also a favored food source for the larvae of some moths and butterflies.  One of these is the handsome black and white Giant Leopard Moth, shown in the photo.  The larva of this moth is a relative of the woolly bear caterpillar, with black fuzzy setae with a reddish bands underneath (see photo above). 

 A couple of bits of dandelion trivia to finish up (from Wikipedia.org):

 “Dandelion yellow” is one of the University of Rochester’s school colors and “The Dandelion Yellow” is one of the school songs.

 Four dandelion flowers make up the emblem of the city of White Sulfur Springs, West Virginia and they have a dandelion festival each spring. 

JA

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