Weed With Fluffy Seed Heads

If you’ve made it outside on a recent sunny day, you’ve probably noticed the abundance of flowers blooming in gardens, parks, forests, and throughout King County right now. Unfortunately, the noxious weeds are out there, too—many of them bolting, flowering, and even going to seed already. Below are some of the top regulated noxious weeds… Wondering how to rid your yard of weeds? Contact Loyalty Lawn Care today for help with professional weed control! Bull thistle is a prickly biennial that grows freely in disturbed soils, pastures, ditches, roadsides and unmanaged spaces. Read here to learn how to get rid of bull thistle and prevent this prolific weed from taking over your garden.

Noxious weeds to watch for in June

If you’ve made it outside on a recent sunny day, you’ve probably noticed the abundance of flowers blooming in gardens, parks, forests, and throughout King County right now. Unfortunately, the noxious weeds are out there, too—many of them bolting, flowering, and even going to seed already.

Below are some of the top regulated noxious weeds to keep an eye out for this month. Please let us know if you see one of these high-priority invasive plants, so we can make sure they’re controlled or eradicated in time! [Click here to go to the King County Noxious Weed List for the whole list!] Report locations and share photos with us easily on our new and improved Report a Weed online form.

1. Top priority: eradicate before seeds disperse

First up, weeds already going to seed or getting close. Catch them now before seeds disperse!

Many garlic mustard plants in King County are going to seed. Note the long, skinny seed pods on this one.

Garlic mustard (Alliaria petiolata), a Class A noxious weed, is a biennial or winter annual herb, can self-pollinate to produce 62,000 seeds and overtake a relatively undisturbed forest understory. Eradicating it before seeds mature is key. You can identify garlic mustard by:

  • Scallop-edged, rounded leaves (on rosettes) or toothed triangular leaves (higher up on mature plants) that feel smooth (hairless) and smell like garlic smell when crushed
  • Small, 4-petaled white flowers and long, skinny seedpods
  • Root bent in a distinct “s” shape
  • Highly variable form, maturing and setting seed at anywhere from a few inches to 6 feet tall

Garlic mustard rosette leaves are more rounded or kidney-shaped, while mature plants have more triangular leaves. All leaves are lobed.

Many shiny geranium plants are forming seed capsules (the crane’s-bill-like shapes next to the flowers), though they aren’t dispersing their seeds quite yet.

Shiny geranium (Geranium lucidum), a Class B noxious weed, is an annual herb that grows in disturbed areas such as roadsides, as well as in shady woodlands and forest openings. This weed is already starting to form seed capsules, though it isn’t dispersing seeds yet. You can identify it by:

  • Reddish, smooth stems that can reach 20 inches tall
  • Shiny, round to kidney-shaped leaves with 5-7 lobes, usually shiny (not fuzzy)
  • Leaves often turn red in sun or as plants are going to seed
  • Tiny pink-purple 5-petaled flowers that appear in pairs at stem ends
  • Keeled sepals
  • Seeds in long capsules that look like cranes’ bills
  • Does not smell bad like herb Robert and is not covered with soft hairs like Dove’s foot geranium

Shiny geranium can invade a variety of areas, from roadsides to woodlands. Photo by Matt Below.Photo by Matt Below.

2. In full flower

The next group of weeds are now in full flower and before long will go to seed. Make sure you eradicate them from your property before they do.

Milk thistle’s large, pink-purple flower head with broad, spiny bracts around its base is in full bloom right now. Photo by Dan Sorensen.

Milk thistle (Silybum marianum) is a Class A noxious weed that grows 2 to 6 feet tall and is a winter annual or biennial that grows mostly in rural parts of King County. You can identify it by:

  • Shiny green leaves with distinct milky-white marbling
  • Spines on leaf edges and stems
  • Large, pink-purple flower heads appearing singly at stem ends
  • Broad, fleshy, spiny bracts around base of flower head

Milk thistle’s large, pink-purple flower head with broad, spiny bracts around its base. Photo by Dan Sorensen.

A bee enjoys an orange hawkweed flower. Be sure to time your noxious weed control so that it has the least impact on pollinators and other animals that might be using the plant.

Orange hawkweed (Hieracium aurantiacum) and yellow hawkweed (Hieracium caespitosum) are two Class B perennial herbs that readily invade roadsides, pastures, grasslands, and other areas throughout King County. Both weeds spread via seeds and stolons. You can identify them by:

  • Hairy, unlobed leaves in rosettes at the base of hairy, almost leafless stem
  • Black, ball-shaped, tightly-clustered flower buds followed by orange (H.aurantiacum) or yellow (H. caespitosum) blooms (look like little dandelion flowers)
  • Milky juice inside all plant parts
  • Fluffy, dandelion-like seed heads
  • Fuzzy white stolons (runners)

Dalmatian toadflax grows especially well in disturbed areas with rocky soil, such as around train tracks. Photo by Sasha Shaw.

Dalmatian toadflax (Linaria dalmatica ssp. dalmatica), a Class B noxious weed, is a perennial plant that grows to 3 feet tall and mostly grows in disturbed areas in western Washington. It spreads by both seed and spreading roots. You can distinguish it by:

  • Multiple stems that grow from one woody base
  • Bluish green, heart-shaped, waxy leaves that wrap around each stem
  • Bright yellow, snapdragon-like flowers growing in rows at stem ends

Sulfur cinquefoil is blooming now, displaying its pale yellow flowers with 5 heart-shaped petals and darker yellow centers.

Sulfur cinquefoil (Potentilla recta) is another Class B noxious weed and perennial herb that reaches 3 feet tall. You can distinguish it by:

  • Palmately lobed leaves with 5-7, long, toothed leaflets
  • Upright, hairy, leafy, mostly unbranched stems (hairs stick straight out from stems unlike on the similar native species graceful cinquefoil, Potentilla gracilis)
  • Pale yellow flowers with 5 heart-shaped petals and darker yellow centers

3. Budding or starting to flower

At a bit earlier stage in their life cycles, the following plants are either budding or just starting to bloom.

Tansy ragwort plants are bolting, and some are even starting to form flowers.

Tansy ragwort (Senecio jacobaea), a Class B noxious weed, is a biennial found throughout King County that is toxic to horses, cattle and other animals. It quickly takes over disturbed areas, thriving in sites with full sun and dry to somewhat wet soils. You can identify it by:

  • Ragged, ruffled leaves that are dark green on top and light-green below, with deeply cut, blunt-toothed lobes
  • First year plants are basal rosettes; second year plants have 2 to 4-foot-tall flowering stalks
  • Clusters of numerous small daisy-like flowers with 13 yellow ray petals and yellow-orange centers
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Tansy ragwort often spreads in pastures and fields where it out-competes grass. It is toxic to horses, cattle and other animals.

Giant hogweed (Heracleum mantegazzianum), a Class A noxious weeds, is a perennial that usually grows in urban areas, especially where there’s rich, damp soil. This plant is poisonous, and touching its sap can cause severe blisters or even scars, so it’s good to know how to recognize it. You can identify it by:

  • 8-15-foot-tall, hollow, ridged stems with reddish-purple blotches and stiff white hairs
  • 3-5-foot-wide, deeply incised, compound leaves
  • Surface of leaf underside is hairless, with hairs only on ribs
  • 2-foot-wide umbrella-shaped flower clusters

Spotted knapweed will soon be blooming. Its silver-gray hue is a good way to identify it even without flowers. Photo by Tricia MacLaren.

Spotted knapweed (Centaurea stoebe), a Class B noxious weed, is a biennial or short-lived perennial that often appears in disturbed areas, especially those with full sun and well-drained soils. You can identify it by:

  • 5-foot-tall, upright, branched stems
  • Medium-green, somewhat silver-gray, often deeply lobed leaves
  • Small, oval flower heads with light purple to pinkish, thistle-like flowers
  • Bracts at base of flower head have triangular black spots
  • Stout taproot

Spotted knapweed’s small, oval flower head with light purple to pinkish, thistle-like flowers. Note triangular black spots on bracts at base of flower head.

Meadow knapweed is starting to bloom, revealing its oval, pink to reddish-purple flower heads. Up close, look for the comb-like fringes near bract tips around the flower head base.

Meadow knapweed (Centaurea jacea x nigra), another Class B noxious weed related to spotted knapweed, is loner-lived perennial that grows in not only disturbed sites, but also riverbanks, pastures, moist meadows, forest openings, and other areas. You can identify it by:

  • 4-foot-tall, upright, branched stems
  • 4-inch-long, slender, often shallowly lobed basal leaves and smaller, unlobed stem leaves, all coarse and tough
  • Single oval flower heads with pink to reddish-purple flowers at branch ends
  • Bracts at base of flower head have comb-like fringe near tip

Meadow knapweed’s oval flower heads with pink to reddish-purple flowers grow singly on stems. Bracts at base of flower head have comb-like fringes near their tips.

Meadow knapweed reaches 4 feet tall, with upright, branched stems. Stem leaves are unlobed and smaller than basal leaves.

4. Plants to keep an eye on

Plants in this final group are putting their energies into growing right now. They won’t go to seed until later this summer, but keep a tab on them and make sure you’re ready to control them when the time comes.

While not 8 feet tall yet, many policeman’s helmet plants are large enough to spot. Look for large, oblong or egg-shaped leaves with serrated edges, growing opposite or whorled in groups of 3 on stems.

Policeman’s helmet (Impatiens glandulifera), Class B noxious weed, is a 3 to 8-foot-tall annual that grows especially well in moist areas, such as wetlands, streams, and damp woodlands. You can identify it by:

  • Upright, hollow, watery, purple-reddish tinged stems
  • Large, oblong or egg-shaped leaves with serrated edges, growing opposite or whorled in groups of 3
  • White to pink to purple 5-part flowers that resemble an English policeman’s helmet
  • Stem base and exposed roots often reddish

Policeman’s helmet has large, oblong or egg-shaped leaves with serrated edges, opposite or whorled in groups of 3.

Purple loosestrife is bolting right now. Look for 4-6-sided stems and simple, smooth-edged leaves appearing opposite or whorled on stems.

Purple loosestrife (Lythrum salicaria), Class B noxious weed, is a deep-rooted, rhizomatous perennial found mostly in damp areas, such as freshwater and brackish wetlands, as well as lakes and streams. It spreads through both vegetative growth and seeds. You can identify it by:

  • Stiff, 4-6-sided stems that reach 6-10 feet tall
  • Simple, smooth-edged leaves that grow opposite or whorled on stems
  • Tall spikes of small magenta flowers with 5-7 petals
  • Woody taproot

Garden loosestrife is growing tall. Look for softly hairy stems and leaves along with lance- or egg-shaped leaves usually arranged in whorls of 3.

Garden loosestrife (Lysimachia vulgaris) is another Class B noxious weed and deep-rooted perennial often found in wet areas, although it’s not related to purple loosestrife (despite the common names). Garden loosestrife spreads primarily via creeping rhizomes. You can identify it by:

Lawn Weeds

Below are some of the typical weeds found in our area. Call us today to identify the weeds in your yard and to discuss the best options to get rid of them permanently.

Broadleaf Lawn Weeds

Black Medic (Medicago lupulina)

Annual, broadleaf (sometimes survives as a short-lived perennial)

Range: throughout the United States

Appearance: With its three leaflet, clover-like leaves, this legume is often confused with white clover. Low growing, with trailing, slightly hairy stems, it produces clusters of small, bright yellow flowers in late spring to early summer.

Growth: Black medic is common in lawns from May through September. It is especially prevalent in dry soils where turf is spotty and in high-phosphorus soils. Though an annual, it can be as persistent as a perennial.

Broadleaf Plantain (Plantago majo)

Range: throughout the United States and southern Canada

Appearance: Broadleaf plantain has gray-green, egg-shaped, wavy-edged leaves growing in ground-hugging rosettes. Narrow seed heads appear in a long cluster on a central, upright stem.

Growth: Rosettes appear in midspring in thin and weakened turf. Seed stalks rise from early summer through September. The rosette has a tendency to suffocate desirable lawn grasses. Plantain grows from seed and resprouting roots. Seed germinates best in rich, moist, compacted soil.

Common Chickweed (Stellaria Media)

Range: throughout the United States except in the Rocky Mountains

Appearance: Common chickweed is a shallow fibrous rooted winter annual which grows in moist shaded areas. The leaves are small, smooth, pointed at the tip and elliptic in shape. They are opposite on branching creeping stems, which root at the nodes. Chickweed adapts well to different mowing heights. The flowers of common chickweed are white small star like with 5 notched petals. Common chickweed spreads by seed.

Growth: Common Chickweed thrives in cool, moist areas. Growing conditions can be made less favorable by lightening the soil or otherwise improving drainage, especially in shady areas. Heavy, constant shade should be lightened as well where possible. Shady areas should be planted with turfgrass species which do well in the shade and which will provide maximum competition to weed species which invade shady areas.

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Clover (Trifolium repens)

Range: throughout the United States

Appearance: The leaves are compound, with 3 broad leaflets (sometimes 4, if you’re lucky!) 1.3 – 2.5 cm long, with tiny teeth on the edges, a pale triangular mark appears on each leaflet.

Growth: Appear from May to September

Curly Dock (Rumex crispus)

Range: throughout the United States

Appearance: Bright, shiny green, lance-shaped leaves appear in spring. In summer and fall, the puckered wavy edges of the leaves are tinted reddish purple. Flowers appear on a tall, narrow spike coming from the center of the plant.

Growth: Growing from a large, brownish taproot, curly dock is a perennial weed that grows most actively when grass is suffering from the stress of hot, dry weather.

Dandelion (Taraxacum officinale)

Range: throughout the United States

Appearance: Everyone recognizes the bright yellow flowers of dandelions; they appear in early spring and are followed by puffy seed heads. They arise from rosettes of lance-shaped leaves.

Growth: Dandelions emerge in early spring, with flowering commencing as early as April and continuing through summer and fall. The plants reproduce from a long taproot, and from seeds. Seedlings can germinate at any time throughout the growing season.

Ground Ivy (Glechoma hederaceae)

Range: throughout the United States

Appearance: Also called creeping Charlie, is a common lawn weed problem. Lawns in shaded areas and often with poorly drained fertile soil are typical sites for ground ivy to develop into a major problem. This plant may form extensive patches as it creeps along the soil and can move into sun areas. Stems are square. Leaves are arranged opposite of each other along stems, and are round to somewhat kidney shaped with rounded, toothed margins. Crushed leaves have a minty odor. Ground ivy has small funnel-shaped purplish-blue flowers.

Growth: April To June

Henbit (Lamium Amplexicaule)

Range: throughout the United States

Appearance: Henbit, a member of the mint family, is an upright winter annual that blooms in the spring. The leaves are rounded on the end with rounded toothed edges that grow opposite one another on square stems Upper leaves lack petioles. Henbit can grow from 4 to 12 inches tall on weak stems.

Growth: Although an upright plant, weak stems sprouting from the bottom may lay almost horizontal. Henbit spreads only by seed and is generally not a problem in dense, vigorous turfgrass sites.

Mouse-Ear Chickweed (Cerastium fontanum vulgare)

Annual or perennial, broadleaf

Range: throughout the United States

Appearance: The name of this weed offers a clue to its appearance. It has long, narrow, fleshy leaves that look fuzzy. Small, white flowers appear in late spring and early summer, followed by seed heads in mid summer.

Growth: This weed grows most actively during spring and early summer when it spreads by means of creeping stems that root at the nodes. It grows close to the ground and can withstand low mowing. It grows vigorously in moist, poorly drained, and shaded areas.

Oxalis (Oxalidaceae)

Range: throughout the United States

Appearance: Has bright yellow flowers and green leaves. It grows upright. O. europaea (also called O. Oxalidaceae) is a perennial with seeds and rootstocks so that it sometimes appears to be a creeping vine. The leaves and stems are often purple or reddish.

Purslane (Portulaca oleracea)

Range: throughout the United States, especially troublesome east of the Mississippi River

Appearance: Sprawling, thick, fleshy stems with rubbery leaves. Tiny, yellow, five-petaled flowers open when the sun is shining brightly. Cup-shaped seedpods produce many small, black seeds that may lie dormant in the soil for years. Seldom found in the spring when the lawn is treated for other weeds.

Growth: Thrives in hot, dry weather, spreading by sprawling stems. It’s extremely troublesome in thin areas of the lawn or in new lawns seeded in summe

Speedwell (Veronica officinalis)

Perennial or annual, broadleaf

Range: Eastern half of the northeastern United States, except in the extreme South

Appearance: There are several types of speedwell, all characterized by small, lobed, and numerous leaves, and by tiny white or purple flowers. The scallop-edged leaves are paired, growing opposite each other. Heart-shaped seed pods grow on the stems below the flowers.

Growth: Speedwells are among the earliest of lawn weeds to appear, greening up as early as late winter. Most are characterized by creeping stems that root at the nodes. Some show an erect growth habit as they mature. They all thrive in cool, moist soils where turf has thinned.

Spurge (Euphorbia esula)

Range: throughout the United States

Appearance: 6 to 36 inches in height. Erect stems support linear, alternate, and apetiolate leaves of a bluish-green hue. The species exhibits yellow-green inflorescence on an umbel near the top of the stem. The yellow-green bracts are the most colorful and conspicuous part of the plant. A milky white sap (latex) is present in all parts of the plant, and aids in identification.

Growth: The plant occurs primarily in non-cropland habitats, including roadsides, prairies, savannas, and woodlands. It is tolerant of a wide range of habitats, from damp to very dry soils.

Wild Violet (Viola Pratincola)

Range: throughout the United States

Appearance: Wild violet is a winter perennial, growing 2 – 5 inches tall. It can have a tap root or a fibrous root system, and also can produce rooting stolons and rhizomes. The leaves can vary but usually are heart shaped, on long petioles with scalloped to shallow rounded margins. The flowers of wild violet range from white to blue to purple. Wild violet flowers are pansy-like with three lower petals and two lateral petals on long single flower stalks.

Growth: Appear from March to June

Sedge Lawn Weeds

Yellow Nutsedge (Cyperus esculentus)

Range: throughout the United States

A related species, purple nutsedge, is especially prevalent in the Southeast

Appearance: Though it resembles a grass, yellow nutsedge is actually a sedge. Its coarse, light green leaves grow upright from triangular stems. Seed heads appear from July to October.

Growth: Reproduces mainly from underground tubers; however, they can reproduce by seeds and underground stems. Tubers store food and are drought tolerant. Yellow nutsedge grows vigorously in summer, especially under moist conditions; primarily troublesome in closely mowed lawns.

Grassy Lawn Weeds

Annual Bluegrass (Poa Annua)

Range: throughout the United States

Appearance: Annual bluegrass has a boat-shaped tip, folded in the bud. The ligule is membranous and auricles are absent. Annual bluegrass has a small panicle seedhead.

Growth: Annual bluegrass contains both annual and perennial species. Annual bluegrass forms dense patches that can withstand low mowing heights. Germination occurs in late summer and early spring.

Barnyard Grass (Echinochloa Crusgalli)

Range: throughout the United States and Mexico

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Appearance: The leaves of barnyardgrass are rolled in the bud and contain neither a ligule nor auricles; the sheath is open but compressed. The mid-vein is thick and keeled; roots are fibrous.

Growth: Barnyardgrass is a summer annual which has tillers which lie flat and form secondary roots resulting in a mat formation. Barnyardgrass spreads by seed which germinate in late spring and early summer. The seedhead is a coarsely branched green to purplish panicle with spiked awns.

Bermuda Grass (Cynoden Dactylon)

Range: Southern areas of the United States

Appearance: The leaves of bermudagrass are folded in the bud, and the sheath is strongly compressed. The leaf is short, approximately 1/8 inch wide with rough edges. The seedhead of Bermudagrass consists of 3 – 7 finger-like spikes.

Growth: Bermudagrass is found in open sunny areas. Bermudagrass does not grow in the shade. It can be found in turf, landscapes and in most cultural crops. Bermudagrass is very tolerant of low mowing, and can be found on both dry and wet soils.

Dallis Grass (Paspalum dilatatum)

Range: Coastal states from New Jersey to California, and as far north as Missouri

Appearance: Coarse blades, somewhat upright in a bunch-type growth. Rhizomes are so closely jointed that they appear almost scaly. Stems 2 to 6 inches long emerge from the plant center in a starlike pattern. Seed heads are sparsely branched on long stems. Seeds lie dormant over the winter and sprout very early in spring.

Growth: This is a summer weed in many areas of the country, but it grows throughout the year in mild climates, and thrives in those areas that are low and wet.

Foxtail (Setaria Glauca)

Range: throughout the United States

Appearance: he leaves are rolled in the bud. The collar is narrow and continuous. The seedhead is a bushy, erect spike which resembles the tail of a fox. GROWTH: Yellow foxtail is a summer annual which germinates when soil temperatures reach 65 degrees F.

Goose Grass

Range: Goosegrass is found in the United States from the transition zone south

Appearance: Goosegrass is a prostrate-growing summer annual. The leaves are folded in the bud. Goosegrass grows in a clump with the base of the leaves being distinctively white to silver in color. The ligule is toothed, membranous, and divided at the center. Goosegrass contains hairs only at the base of the leaf.

Growth: Goosegrass is highly competitive during hot summers, and can outcompete desirable grasses where soil is compacted. Core aeration should be provided to improve soil conditions for desirable grasses. Single plants can be physically removed with a knife. Do not seed when soil and weather conditions are appropriate for the germination of goosegrass (60 to 65 degrees F). A slightly raised mowing height may help prevent the establishment of crabgrass by providing shade from sunlight.

Smooth Crabgrass and Hairy Crabgrass (Digitaria Ischaemum and D. Sanguinalis)

Annual, grassy

Range: throughout the United States

Appearance: Smooth and hairy crabgrass have a prostrate growth habit with coarse, light green blades. The blades are short, pointed, and hairy.

Growth: This vigorous, warm-season annual grass grows rapidly from early spring until seed heads form in late summer to early fall. It grows especially well in lawns that are watered lightly, underfertilized, poorly drained, and growing thinly. The plant spreads by seed, and to a lesser extent, by rooting from the lower swollen nodes of stems.

Bull Thistle Control: Managing Bull Thistle Plants In Gardens

Bull thistle (Cirsium vulgare) is a plant that is related to the sunflower family but has none of the charm and beauty of those sunny-nodding flower heads. It is a prickly biennial that grows freely in disturbed soils, pastures, ditches, roadsides and unmanaged spaces. The plant has colonized much of North America and is a pest plant in the garden and in agriculture. Bull thistle control can be manual or chemical, with an emphasis on seed control. Learn how to get rid of bull thistle and prevent this prolific weed from taking over your garden.

What is Bull Thistle?

Bull thistle plants are native to Western Asia, North America and parts of Europe. What is bull thistle? It’s a free-seeding weed with a prickly demeanor and rapid spread. The plant has the ability to produce around 5,000 seeds in a season. These bur-like seeds cling to animals, pant legs, machinery, etc. and get spread around with abandon. For this reason, bull thistle removal is a priority among farmers and meticulous gardeners.

Bull thistle starts life as a spiny leaved rosette. The hairy, prickly leaves overwinter to develop stems and branches of up to 2 feet (61 cm.) in spring. It has a deep taproot, which makes manual pulling a challenge.

In summer the plant grows a scented flower that resembles a spiny globe topped with fringed pink petals. The flowers are produced at the ends of the tangled stem growth and last for several weeks before producing tiny striped seeds capped with white downy hairs. These attach themselves to any object that brushes against them.

How to Get Rid of Bull Thistle Manually

The stubborn plant can arise like Lazarus from the ashes if hand pulling leaves behind any of the root. Casual removal with this method is likely to leave behind the genesis of a plant in spite of the foliar amputation.

Digging the plant out with a spade or hori hori is the best approach to mechanical bull thistle control. Take care to remove the entire fleshy taproot for best results. In order to reduce the seed population, cut off the seed head and tuck it into a sack to keep the fluffy seeds from dispersing.

Other Types of Bull Thistle Removal

In agricultural situations, the introduction of a bull thistle seed head gall fly has been proposed as a biological agent. However, it has been shown to have limited effectiveness. There is also a weevil that is an effective control agent, but it can also affect desired thistle species.

Chemical treatment is most effective on the first year rosettes of bull thistle plants. The types of sprays used in agricultural scenarios are dicamba, glyphosate or 2,4D.

Note: Any recommendations pertaining to the use of chemicals are for informational purposes only. Specific brand names or commercial products or services do not imply endorsement. Chemical control should only be used as a last resort, as organic approaches are safer and more environmentally friendly.

For widespread control, mowing twice per year has been effective in reducing the population by preventing seed heads. Of course, your battle with the plant will only be as effective as your neighbors’ because of the travel ability of the downy seeds.