5 Winter Weeds To Watch For

5 Winter Weeds To Watch For

If you've been watering all winter, you may need to wage a war on weeds. Here are the five usual suspects that may be infiltrating your lawn.

Cool temperatures and winter precipitation make picture-perfect growing conditions for cool-season weeds. With turf grass still dormant, irrigated lawns present huge opportunities for winter weeds.

Most weeds of bare winter lawns are pretty tough wildflowers in their own right, and many provide some habitat value at the end of the long cold season. But if you want better habitat — or a wildscape — the best way to start is by shrinking that endless empty lawn and planting some evergreen shrubs and hedges.

Then again, if all you want is spring weeds, just add water. If your sprinklers have been running all winter, your weeds have a huge head start. Here are a few of the most noticeable beneficiaries of your winter water bill:

  • Beggar ticks (Torilis arvensis) - Hedge parsley looks innocent enough when its tiny white flowers are in bloom, but beware: by the time the seeds mature in spring, they’ll be coated in those tiny prickles that completely coat shoelaces, socks, pants and pets.
    Beggar Tick
    Beggar Tick (Torilis arvensis)

  • Bedstraw (Galium sp.) - Call it cleavers, catchall or Velcro plant: the name describes the scratchy hooks that cover the leaves, stems and seeds. Bedstraw forms climbing, tangling, sticky piles of smothering mass in moist shady places. It can be a major irritant for us mammals and gardeners, and a smotherer of small wildflowers and spring bedding plants. Bedstraw (Galium)
    Bedstraw (Galium)

  • Henbit (Lamium amplexicaule) - Pink and purple flowers on square mint stems are the hallmark of henbit, which forms spreading piles in flowerbeds and lawns. It makes for nice flower arrangements, which may be a good thing since it dominates turf grass this time of year.
  • Henbit (Lamium amplexicaule)
    Henbit (Lamium amplexicaule)

  • Sow thistle (Sonchus oleraceus) - In its early stages it may be mistaken for dandelion or poppy, but the clawlike leaves can give a nasty shock if you rub them the wrong way. Both the young leaves and the pickled flower buds are edible. If your sprinklers have been running in winter, you may have a bumper crop.
    Sow thistle (Sonchus oleraceus).
    Sow thistle (Sonchus oleraceus).

  • Bastard cabbage (Rapistrum rugosum) The name says it all – this giant perennial mustard bush can grow up to four feet tall and cover the roadways in central Texas with a monoculture of tiny yellow flowers resembling broccoli – especially after a wet winter. It’s a particular ecological threat because it crowds out Texas wildflowers. The huge basal rosettes are a familiar sight in any winter turf, since bastard cabbage is often introduced through contaminated grass seed mixes.
    Bastard Cabbage (Rapistrum rugosum)
    Bastard Cabbage (Rapistrum rugosum)

The best weapon against weeds at this point is your lawnmower or weed eater. Just remember for next year (before you hit the pre-emergent herbicides!) that we always recommend turning your sprinklers off — or at most running them manually — between November and March. The only reason to run irrigation in winter is to provide moisture to roots, and only if needed; as long as it rains once a month, you shouldn’t need to supplement it at all. Especially with the winter weeds waiting like barbarians at the gates.

Turning off your irrigation system in winter can help more than your weeds; it can lower your monthly sewer bill, too. Remember, your sewer rate is based on your average household water consumption in winter, when your sprinklers are off.

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Brad Wier

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Brad Wier

Brad Wier is a SAWS conservation consultant. Years in South Texas landscaping and public horticulture gave him a lasting enthusiasm for native plants that don’t die when sprinklers -- and gardeners -- break down. He’d rather save time and water for kayaking and tubing. He is a former kilt model, and hears hummingbirds.