What’s Up With Weeds: November

A November to remember…to take care of those tools!

Digging in the Dirt

A sharp shovel makes a tough job easier

By the time November rolls around, the rains of winter have returned to the Northwest. This is the time of year when we pull the sweaters out of summer storage and start winterizing our homes. The wet rains and cool weather of November also signals the start of the winter armistice with the weeds. Apart from a few year round enemies like English ivy and Spurge laurel, most weeds have begun to slow down for the long rainy season ahead.

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Early detection is the key

This slow down makes November the perfect time to stop and reflect upon your accomplishments over the last season, and give thanks for the year you have had–or at the very least the Turkey dinner and pumpkin pie you’ll enjoy! So as you plan to sharpen that carving knife for the Turkey Day, think about all those tools in your shed that could use a good sharpening as well.

Shovels, shears, saws, and axes. Machetes, hoes, mattocks, and Pulaskis. Picks, pullers, claws, and McLeods all of your favorite hand tools could use a good sharpening. So take some time to hone an edge for the new year ahead. Pulling tools like weed wrenches, extracigators, and shrub busters can benefit from a good oiling after a year of service. And November is a great time to do some yearly maintenance on your back pack sprayers. Check all hoses, filters, and nozzles for wear and replace anything showing excessive wear.

For heavier equipment like chainsaws, weed whackers, mowers, and boom sprayers review your owners manuals for all recommended maintenance, or take them to an authorized dealer or service center for maintenance.

So take care of your tools and they will take care of you.

So what is up with Weeds in November?

Grass-like plants

  • Jubata grass (Cortaderia jubata) is an annual shrub that follows the same timeline as Pampas grass. Plants have seeded. Dig up the entire plant.
  • Common reed grass (Phragmites australis) is a grassy perennial. Plants that were emerging in April, May, and June are seeding, cut and bag seed heads and dispose in trash.
  • False brome (Brachypodium sylvaticum) is a perennial grass. Plants have seeded and going dormant. Please [contactweedwise] if you see false brome!

Herbaceous flowering plants

  • Russian knapweed (Acroptilon repens) bolts in May with flowers appearing in June, July, and August. Control can be through handpulling, tilling, mowing, or digging. Root fragments resprout so it’s important to get all of the plant out of the ground.
  • Garlic mustard (Alliaria petiolata)was forming rosettes through the winter and flowers in April and May. Seeds may be present and viable from June through September! You can hand pull plants, although root fragments can resprout. Please [contactweedwise] if you see garlic mustard!
  • Spotted knapweed (Centaurea biebersteinii) follows the same timeline as Diffuse knapweed. Dig up the entire plant (easier when soil is moist in the spring).
  • Purple starthistle (Centaurea calcitrapa) sprout from seed in winter and develop into rosettes in spring. Starthistle plants flower from July to Spetember. Please [contactweedwise] if you see purple starthistle in your area.
  • Meadow knapweed (Centaurea debeauzii) follows the same timeline as Diffuse knapweed. Dig up the entire plant (easier when soil is moist in the spring).
  • Diffuse knapweed (Centaurea diffusa) is a herbaceous perennial. In May, plants bolt. Flowers appear in May, June, and July. Dig up the entire plant (easier when soil is moist in the spring).
  • Yellow starthistle (Centaurea solstittialis) sprout from seed in winter and develop into rosettes in spring. Starthistle plants flower from May to July. Please [contactweedwise] if you see yellow starthistle in your area.
  • Rush skeletonweed (Chondrilla juncea) bolts in April, May, and June. When it flowers in July, it sets seed quickly!
  • Paterson’s curse (Echium plantagineum) emerges in March and April, flowering all summer.
  • Orange hawkweed (Hieracium aurantiacum) can be dug up in March and April. Be sure to get the roots and runners. Flowering occurs in May and June, and can extend later, with flowers and seeds occurring from July through September. More information is available on the Oregon Department of Agriculture’s page about Orange hawkweed. Please [contactweedwise] if you see Orange hawkweed!
  • Yellow-flag iris (Iris pseudacorus) is a herbaceous perennial that emerges in April and flowers in May and June. Seeds are set from July through September
  • Yellow archangel (Lamiastrum galeobdolon) is a herbaceous perennial the grows throughout the winter and flowers from April to June. Seeds are set in July and August.
  • Kudzu (Pueraria lobata) is a vining perennial. Leaves emerge in April, May, and June. Flowers emerge in July. Please [contactweedwise] immediately if you think you have spotted Kudzu in Clackamas County!
  • Lesser celandine (Ranunculus ficaria) is a herbaceous perennial. Rosettes form in January and February, and the plants flower in March. In April, seeds are set. Remove all of the bulblets and tubers.
  • Tansy ragwort (Senecio jacobaea) is a herbaceous biennial. Rosettes form in March and April, and flowers in May, June, and July. If soil is moist, dig up the rosettes. If you remove the plant during flowering, bag the plant so seeds can’t spread.

Shrubby plants

  • Blessed milk thistle (Silybum marianum) overwinter as rosettes that bolt in March, April, and May. The plants flower in June and July. Mow or hand pull before flowers fully develop.
  • Butterfly bush (Buddleia davidii), a tall deciduous shrub, displays new leaves in April, May, and June, but doesn’t generally flower until July and August. Control by digging up the entire plant. Our Weed Wrench might work!
  • Giant hogweed (Heracleum mantegazzianum) is a tall herbaceous perennial. Plants emerge in March and April from winter rosettes, and accelerate in growth in April and May. When the plants flower in June and July, remove the heads and cut off the plant at the base…but be very careful because the sap of this plant is caustic. ODA says this about Giant hogweed: “This plant is a public health hazard. Do not expose bare human skin to the plant or breathe the smoke from fires if it is being burned. The plant exudes a clear watery sap which sensitizes the skin to ultraviolet radiation. Humans often develop severe burns to the affected areas resulting in blistering and painful dermatitis. Blisters can later develop into purplish or blackened scars.” Please [contactweedwise] immediately if you spot this plant!
  • Gorse (Ulex europaeus) is a single to multi-stemmed spiny shrub that buds in February and flowers in March, April, and May. It goes to seed in June and July. Dig up small plants. Please [contactweedwise] if you see gorse!
  • Policeman’s helmet (Impatiens glandulifera) is a herbaceous annual the begins to emerge in April and grows through May. Flowers appear in June and July.
  • Purple loosestrife (Lythrum salicaria) is a herbaceous perennial that emerges in May and June. Flowers begin to appear in July.
  • Scotch thistle (Onopordum acanthium) is a herbaceous biennial that overwinters as rosettes. Flower stalks emerge in June and flowering is in July and August.
  • Spurge laurel (Daphne laureola) is an annual shrub that emerges in March and flowers in April, May, and June. Berries appear in June and July. Dig up as much of the plant and root system as possible. Please [contactweedwise] if you see spurge laurel!
  • Knotweeds include Japanese knotweed (Polygonum cuspidatum), Giant knotweed (Polygonum sachalinense), Himalayan knotweed (Polygonum polystachyum), and hydrid knotweeds began emerging in April. With warmer temperatures, growth accelerates throughout May and June. Flowers emerge in July and August. Mechanical control requires frequent, persistent effort: cut twice each month from April through August. In the fall, additional steps are needed, including cutting and covering the plants. Knotweeds are so persistent that you need to do this repeatedly for five years to achieve control.

Aquatic plants

  • Parrot’s feather (Myriophyllum aquaticum) is a perennial with underground rhizomes that overwinter. Stems emerge in April and May. Flower stalks appear in June and July. Removing the entire plant, including root fragments, is necessary.

Report weeds!

Visit our page on reporting weeds to file a report.

The images on this page are public domain. Photo courtesy Swedish National Heritage Board, Flickr Commons

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