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seeds that fell in weeds

Identifying Fall-emerging Weeds

2020 Update: I believe marestail will be a problem this fall and require an alternate herbicide as the majority of marestail in eastern Nebraska is resistant to glyphosate and ALS-inhibiting herbicides. Amit Jhala

As the 2020 corn and soybean harvest begins to wind down, we would like to encourage growers to take a proactive approach to managing winter annual weeds prior to the onset of winter. Winter annual weeds typically emerge in late summer and fall, survive throughout the winter, and produce seeds during late spring or early summer the following year. Fall control can prevent potential yield reductions associated with delaying removal until corn or soybean planting the following year.

UNL Weed Management Scientist Amit Jhala, explains why fall control of winter annuals is important in this Oct. 24, 2014 Market Journal interview.

With recent precipitation, many winter weeds are actively emerging. These weeds require undisturbed soils from fall through early summer of the following year to complete their life cycle, and no-till soil management favors this environment. The most common winter weeds in Nebraska are: henbit, marestail, field pennycress, downy brome, dandelion, shepherd’s-purse, tansy mustard, and prickly lettuce. In addition, little barley, evening primrose, and field pansy have been observed in many fields. The first step in effective weed management is being able to accurately identify the weeds.

Here are tips to properly identify fall emerging weeds:

Henbit

Henbit is a winter annual (sometimes biennial) herb found in cultivated areas, field, roadsides, or lawns.

Flowering period: March-May

Distinguishing features: The plant is 4 to 12 inches tall having squared green-stem (often becoming purplish in later stage) and reddish purple to pink flowers. The leaves are opposite, clasping the stem in the top portion and leaf-margins are crenate and lobed. The whole plant is sparsely covered with fine hairs. Stem branches frequently root from the nodes. The foliage and stems of henbit are aromatic.

Seedling characteristics: It has a 3-12 mm long, oval-shaped cotyledon with a smooth surface. The petiole is green or purplish and has spreading hair.

Marestail

Marestail, also known as horseweed, is an annual weed that has a winter or summer annual life cycle. They usually germinate in fall but can germinate in mid-summer when conditions are favorable. Plenty of marestail can be found in no-till fields as well as in cultivated areas, pastures, and roadsides. Marestail contains volatile oils, tannic acid, and gallic acid that may cause skin and mucosal irritation in humans and livestock. Glyphosate-resistant marestail has been confirmed in Nebraska. This is a serious issue and growers should be on the lookout for possible occurrences this fall.

Flowering period: June-September

Distinguishing features: This is an erect herb that has coarsely hirsute stem and leaf surfaces and can be 1.5 to 6 feet tall. It tends to be unbranched unless the plant has been damaged by herbicides or mowing, but it may have branching at inflorescence. Leaves are alternate and crowded on the stem. Flowers are white to pink (ray florets) with yellow centers (disk florets). After fall germination it forms a rosette-like structure. (The larger the rosette is in the fall, the greater its chances of surviving through winter.) Depending on growing conditions, the survival rate of fall-emerged marestail is 14%-84% of total germinated weeds.

Seedling characteristics: Seedlings are also covered by coarse hairs. The margins of the first leaves of rosette are mostly entire or round, but subsequent leaves might be apically projected and toothed.

Field Pennycress

Field pennycress is a winter annual that can be found in fields, pastures, roadsides, and in disturbed lands. Field pennycress seeds contain a chemical (allyl isothiocyanate) that causes gastric distress in livestock. When the seeds are consumed, cows produce milk with a bitter garlic odor and flavor.

Flowering period: April- June

Distinguishing features: The stem is erect, branched or simple, and 1 to 2.6 feet tall. Leaves are alternate and clasping the stem. It forms a basal rosette with the leaves. Lower leaves have entire or coarsely toothed margins with blunt tips, while upper leaves have coarsely toothed margins with a projected leaf tip. Fruits are flat, circular, or rounded-oblong. They are notched at the tip, separating into two valves.

Seedling characteristics: Cotyledons are bluish-green and long-stalked. They are ovate-shaped with a prominent mid-vein and slightly toothed margin.

Downy Brome

Downy brome is a winter annual grass that can be found in cultivated areas, fields, pastures, roadsides, and waste sites. Long awns of downy brome may injure grazing animals and cause tetanus.

Flowering period: Late April- May

Distinguishing features: Plants are 0.3 to 2 feet tall. Leaf sheaths, leaf blades, and nodes are covered with soft hairs. Usually the leaves twist clockwise. It has a membranous (1-3 mm long) structure at the base of the leaf where the leaf blade and leaf sheath (i.e. ligule) meet. Long awned spikelets form panicles (inflorescence) that are dense, soft and either drooping or nodding.

Seedling characteristics: Seedlings are light green with soft hairs on the leaf sheath and blades. Leaves show clockwise twisting.

Dandelion

Dandelion is an annual or perennial weed invasive in turf, flower gardens, forage, and no-till fields. It grows from seeds during fall.

Flowering period: April-October

Distinguishing features: The erect plants are 2 to 20 inches high and have a basal rosette crowded by deeply notched leaves. Stems and leaves contain milky sap. The bright yellow dandelion flower is 1 to 2 inches wide. Each flower head contains hundreds of ray florets. Later the flower heads turn into white globular seed head. Each seed has a white parachute that facilitates travel on the wind.

Seedling characteristics: It has a rosette that’s 2 to 6 inches long with basal leaves formed above the central root system.

Shepherd’s-purse

Shepherd’s-purse is a winter annual (rarely biennial) mostly found in cultivated areas, fields, lawns, gardens and roadsides. The seeds of shepherd’s purse need cold temperatures to break dormancy and germinate when the soil temperature goes below 60°F.

Flowering period: March- November

Distinguishing features: The leaves are alternate, forming a basal rosette. They are pinnately lobed and smaller apically. The flower stalks (called raceme) are unbranched to slightly branched. The plant will be 6 to 18 inches tall and bear white flowers. The fruits of shepherd’s purse are triangular- or heart-shaped.

Seedling characteristics: Cotyledons are round or spatulate in shape and may be slightly indented at the tip.

Tansymustard

Tansymustard is a winter annual that can be found in rangeland, roadsides, and fields. It contains toxic levels of nitrate and is harmful for cattle to consume.

Flowering period: March-August

Distinguishing features: The leaves are segmented in a narrow pattern. Plants are 0.3 to 2.9 feet tall with simple or branched stems. Flowers are bright yellow and fruits (called silique) are club-shaped similar to mustard fruits.

Seedling characteristics: Seedlings are reddish green to purple.

Prickly Lettuce

Prickly lettuce is a common winter annual found throughout the Great Plains in disturbed habitats, roadsides, gardens, pastures, and cultivated fields. It causes pulmonary emphysema in cattle when consumed in large quantity.

Flowering period: July-September

Distinguishing features: Leaves are alternate and deeply dentate. Middle to lower leaves have stiff bristles along the bottom mid-rib. Stems contain a substance that looks like white latex. Each flower head contains up to 25 yellow flowers. Each flower looks like a small dandelion flower.

Seedling characteristics: Seedlings exist as a basal rosette until flowering stems develop.

Treatment

Several herbicides have been registered for control of fall emerging weeds. The CropWatch article Managing Winter Annual Weeds Starts this Fall provides good information for fall weed management. For more details about herbicide options for fall emerging weeds, see the 2020 Guide for Weed Management in Nebraska, EC 130.

Seeds that fell in weeds

Weeds. A weed is defined as a plant growing where it is not wanted or intentionally sown. A plant that competes or interferes with the activity of deliberately placed plants.

Weeds. God has been speaking to me about the weeds in our life.

Jesus speaks directly to the thorny weeds in the Parable of the Sower (Matthew 13, Mark 4, and Luke 8). A parable is a simple story used to illustrate a moral or spiritual lesson. The narrative states Jesus was teaching a large group of folks. His story telling of these four different scenarios would most definitely encompass them all. In this story, although mightily important, the Sower is not the focal point, he goes about sowing, scattering the seed at will. The seed, although powerfully essential, it too is not the prominent point. The point is the receiving ground.

Four Seeding Scenarios: First, the seed fell on the path, where it was trampled and became bird food. The second, the seed fell on rocky ground, where it sat in shallow dirt, exposed, receiving no nutrients or moisture, and dried up. The third, the seed was among the thorny weeds, the thorns choked out the seeded plants. The fourth, the seed fell on good ground, matured, producing fruit.

Notice the first two seedings don’t really hit the soil, they are on the path and rocks (external). The second two are “soiled” (internal). The seed, which Jesus explains is the Word of God, it is taken in – into the heart.

In that area, Palestinian weeds like these thorns can grow up to six feet in height and have a major root system. Regardless of the Godzilla size, the weeds compete for nutrients. This competing-choking literally means to suffocate. To suffocate is to halt the ability to thrive, to breathe, to live. Fascinating. The Word of God is “God-breathed” (2 Timothy 3:16).

Jesus goes on to explain, “ The seeds that fell among the thorns represent those who hear the message, but all too quickly the message is crowded out by the cares and riches and pleasures of this life. And so they never grow into maturity ” (emphasis mine, Luke 8:14, NLT).

Cares, riches and pleasures AND the word of God. Yep. Sounds crowded. Our worries, cares easily bleed into anxiety, which brings disruption to the mind, the heart and yes, the soul. Riches can be defined as seeking hard after “having the wants.” And pleasures, those distractions that pull our look elsewhere for gratification. Individually they are not bad. But. When they take time, effort and attention away from the Word, we end up having no time for it – no time for God.

Yes, weeds. “But all too quickly” they suck the ever-loving God stuff right out of our life. Our receiving ground starts strong – but the distractions come, the concern for spiritual things are crowded out by material things. The potential of fruit has just shriveled and never matured.

Weeds. What worries suffocate you? What are you seeking hard after? God, His word, or stuff? What distractions have you looking – what has your attention?

Know YOUR weeds.

How are weeds established? Literally, they are poop droppings (eewwWW) or they are blown in by the winds. They are brought in with fill dirt. How are they destroyed? They are pulled. They are dug deep and pulled, making sure you get the whole root, if not, the remains will continue to grow. They are pulled out before they have a chance to flower and reseed – multiply.

Weeds. Competing or interfering with the activity of the deliberately placed Word of God. Watch your dirt. Protect the seed. Do some weed pulling.

In Him, DeDe (“Let us consider how we may spur one another on toward love & good deeds” – Hebrews 10:24).

*Thank you to my Master Gardener friend Kathy B for your insightful advice on tending to weeds.