University of Maryland Extension

Weed of the Week Index

Landscape and Nursery IPM Reports:

Weeds for 2011-2016:

Algae, filamentous15Aug14
Amaranth, palmer15May 01
11Jun24
Amaranth, spiny11Jun03
Automation and weed control12Sep07
Bamboo14May16
Barberry, Japanese14Jun06
Bedstraw, catchweed13May24
Beefsteak plant (Perilla frutescens)15Jul24
Beggartick, nodding13Aug02
Bermudagrass15Jul17
Bittercress, hairy

14Sep05,
12Oct05
, 12Mar16

Bittersweet, Oriental/Asiatic

15Jul10

Bluegrass, annual and roughstalk

17Apr07

15Apr24
14May02

14Apr18
12Apr06

Bluegrass, roughstalk13May03
British yellowhead (meadow fleabane)12Jul13
Broadleaf weed control alternatives13Oct25, 13Oct18, 13Sep20
Brunnera macrophylla 'Dawson's White'16Oct14
Burcucumber16Oct07
11Jul01
Buttercup, bulbosus (Ranunculus bulbosus)16May20
14May30
Buttonweed, Virginia12Oct05
Canarygrass, reed12Jun22
Carpetgrass (Arthraxon hispidus)13Jul19
Cat's ear, common (false dandelion)12Jul06
Chickory (Cichoriium intybus)16Oct21
Chickweed, common16Apr15
Chinese yam (Dioscorea batatas)13May31
Cinquefoil, common14Oct24
Cinquefoil, sulfur12May11
Clematis terniflora11Oct21
Clover, white12Jun01, 12May25 (a lot in nurseries this year)
11Sep30
Cocklebur, common13Oct18
Crabgrass16Mar18 (early spring control)
13Apr19
12Mar09
(Jeffrey Derr article)
11Mar18 (focus on control)
Daisy, fleabane14Oct03
Dayflower, Asiatic or common14Jul11
Deadnettle, purple16Apr29
12Apr13
Deadnettle, white spotted (Lamium maculatum)16Apr08
Dock, broadleaf13Apr12
Dodder15Jul31
13Jun21
11Aug26
Dogbane, hemp12Aug03
Dollar weed13Oct11
Drift issues13May17
False (also fool's) parsley (Aethusa cynapium)16May27
Fescue, meadow11May06
Foxtail, giant13Sep06
12Oct19
Geranium, Carolina16Jun10
14Jun27
Goat's beard (Tragopogon dubius)16Jul01
Goutweed (Aegopodium podagraria)15Jun05
Greenbrier (Smilax spp.)15Oct16
Groundsel, common13Jul05
Hemlock, poison13Jun14
Herbicide use and rainscapes14Sep12
Herbicides: Understanding why they work14Apr04
Hog peanut16Sep16
Hogweed, giant13Jun28
12Jun08
Horsenettle13Jul26
Indian mock strawberry (Duchesnea indica)15Oct09
Invasive plants - New MDA Tier 1 and Tier 2 plants16Apr29
Italian arum17Mar17
Jewelweed (Impatiens capensis), native, but reseeds well and can be a problem in some situations16Jul22
Johnsongrass11Jul29
Joint-head grass (Arthraxon hispidus)15Oct01
Knapweed, spotted11Apr08
Knotweed, Japanese16Jun17
15May08

13Aug30
Knotweed, prostrate11Jun10
Lambsquarters13Sep20
Lespedeza, Chinese11Oct07
Lespedeza, common (Kummerowia striata (syn. Lespedeza striata)

16Oct28
14Jul03

12Aug31

Lesser celandine

17Mar24

16Apr01, 16Mar18 (sighting for report)
14Apr11

13Mar22
11Apr15

Lesser-seeded bittercress13Mar29
Lettuce, prickly (Latuca scariola)15Jun26
Lettuce, willow leaf (Lactuca saligna)15May29
Marestail13Jul12
Medic, black14Oct17
Mile-a-minute weed16Aug12
13Jul05
, 13Jun28
Morning glory, ivyleaf12Sep14
Morning glory, tall14Aug22
Mulberry tree14Aug15
Mulberry weed13Aug23
11Jul08
Mullein, common12Aug10
Mustard, blue13Apr05
11Apr15
Mustard, garlic15Jun12
Nettle, European stinging12Aug24
Nightshade, bittersweet (Solanum dulcamara)16Jul15
Nimblewill (Muhlenbergia shreberi)15Sep04
Nutsedge, yellow16Sep23 (photo of nutlets)
16Jul08

15Mar20
(control update)
14Aug08
Panicum, fall16Oct14, 16Aug26
11Sep23
Parsnip, wild12Mar09
Pennycress, thoroughwort11May13
Phyllanthus, long-stalked15Oct30
Plantain, broadleaf14Jun13
Pokeweed14Aug01
Porcelainberry14Sep12
Prickly lettuce11Apr22
Purple deadnettle (Lamium purpureum)17Mar31
Purslane, common14Sep25
Queen Anne's Lace (Daucus carota)15Sep25
Radish, wild11May27
Ragweed, common11Sep02
Ragweed, giant12Jul20
Ragworm13Apr26
Ravenna-grass11Oct14
Redstem filaree11Sep09
Salsify (or goat's beard)12Jun01
Sandbur (Cenchrus)15Sep18
Shepherd's purse (Capsella bursa-pastoris)16Apr22
Smartweed, Pennsylvania12Jun15
Sorrel, red12Sep07
Sowthistle, common11Apr29
Sowthistle, spiny12May25
Speedwell, common (Veronica officinalis)17Apr14
Speedwell, Persian (Veronica persica)17Apr21
Spurge, spotted16Aug19
14Jul18
Star-of-Bethlehem (Ornithogalum umbellatum)15May22
Stiltgrass, Japanese12Apr20
11Oct07 (fungus found that infects this weed)
Teasel, common11Aug05
Thistle, Canada16Sep30 (infected by bacteria)
13May10
11Apr01
Thistle, nodding15Aug21
Thistle, tall (Cirsium altissimum)16Jun03
Timothy (Phleum pretense)16May13
Tree of heaven (Ailanthus altissima)15Jul02
Velvetleaf11Jul22
Violet, field12Mar30
Violet, wild13Sep27
Virginia buttonweed11Sep16
Virginia creeper14May23
Weed control and heavy rains15Jul02
Weed control challenges: timing, soil moisture16Sep02
15Aug07
Weed control problems in turf13Aug09
Weed control: management practices15Oct23
Weed control: soil temperatures16Mar25
Weed control review for fall germinating weeds15Aug14
Weeds in perennial beds13Aug30
Weed management in spring14Mar28
Wild violets (Viola pratincola)16May06
Wineberry (Rubus phoenicolasius)16Nov04
12Jul27
Witchgrass (Panicum capillare)16Jul29
Woodsorrel, yellow14Sep19
Yellow archangel11Oct28
Yellow rocket12Nov02
Yellowcress, marsh15Jun19
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