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

 

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Japanese Knotweed is a beautiful plant when in full, white flower stage. Too bad it is such a thug and invasive. It also makes a nice hedge, but quickly overtakes the properties if used as a boundary plant. Colonies can be seen just about everywhere along roadsides, in meadows and yards as it spreads so freely.

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Japanese knotweed is also known as Japanese bamboo, American and Mexican Bamboo due to its hollow stems with nodes on them. The plant is known by three different Latin names of Fallopia japonica and Polygonum cuspidatum Siebold & Zucc.  And Reynoutria japonica Houtt, but it all the same plant. No matter what you call it, it is aggressive, invasive and extremely hard to kill once established.

The plant was brought to the United States during the 1890’s from Asia as a solution to erosion. It will grow in just about any situation from full sun to complete shade, rich or lean soils, and dry or soggy soils. It tends to make a colony of plants, out-competing any and all other plants resulting in a monoculture. Since it evolved on another continent, it has no native predators, insect or animal that eats it enough to control its spread.

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It reproduces vegetatively. If digging it out, any tiny piece of root left in the ground will quickly send up a shoot to get reestablished.  Control measures are difficult. Heavy machinery can dig out large infestations and monitor for a new sprouts to pull or treat with herbicides. Herbicides which contain Glyphosate or Triclopyr are the most successful and should be used before the plants flower or sprayed on cut stems. It has been reported that monthly mowing for five years will finally eradicate a large area.

 

-Carol Quish

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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