Noxious Weeds in Your Landscape

Ah, getting out into the garden again.  It is a true pleasure after the long, long break I’ve had.  And of course, it is an instant reality check.  The garden… it’s not Eden!  Today I’m going to talk about a few of my least favourite “rooting shooting” weeds and how to control them without the use of banned pesticides.

Field bindweed/hedge bindweed (Convolvulus species).

field bindweed

Field bindweed (Image cut from http://www.agf.gov.bc.ca/cropprot/weedguid/bindweed.htm)

hedge bindweed

Hedge bindweed (Image cut from http://www.agf.gov.bc.ca/cropprot/weedguid/bindweed.htm)

Field bindweed has smaller leaves and flowers. Hedge bindweed looks like a lovely white morning glory.  Either way, it’s best just to eliminate any sign of them as quickly as possible.  The roots can run forever and the seeds will outlast me.  Trying to get rid of what seems like MILES of cable-like roots is excellent exercise, but disruptive to the garden bed.  It’s easiest to eliminate them completely while they are very young.

Thistles — Scotch (Onopordum acanthium) and other.

You know what I mean.  The prickly things whose white roots go down forever and just don’t want to die.

Sheep sorrel (Rumex acetosella)

sheep sorrel 1sheep sorrel 2

(Images cut from http://www.agf.gov.bc.ca/cropprot/weedguid/sheepsor.htm)

This little weed is only classified as a “nuisance weed” in BC.  However, if it is in your landscape it will make you curse just like the others as it chokes your bed.  One of my landscaper friends calls it “elastic weed” because its roots ARE very elastic.  You can dig (and dig!) and carefully pull, but chances are it will eventually stretch and snap.  The red-flowered females are the ones that will form seeds.  Don’t let that happen.  That will just give it a jump on you.

English Ivy (Hedera spp.)

When I lived in Saskatchewan, ivy was something I grew in a pot in my home and yearned after as a bonsai subject.  When I arrived in BC, I saw it covering forest floors and creeping up very tall trees to rob them of sunlight.  After seeing that, ivy is just not pretty any more.  Add in that it is habitat for rats… really not feeling the ivy-love anymore.

Once English ivy begins to flower and seed, the situation becomes even worse. Starlings (another invader) eat ivy berries and spread the seeds to our yards and forests, where they readily grow. Ivy replaces desirable plants that provide valuable wildlife habitat, becoming an “ivy desert”.  Once it grows up a tree, it not only blocks sunlight, but it makes the tree more top-heavy than it should be.  That contributes to blowdown in our winter winds.

Please reconsider any outdoor plantings of ivy.  If you already grow ivy, remove it.  Replace it with clematis, climbing honeysuckle, or some other non-invasive selection.  It could be a great opportunity to introduce native plants into your landscape!

If your land or trees have already been invaded, please refer to this website for information on how to best handle that situation:

http://www.pesticide.org/solutions/home-and-garden-toolbox/weed-solutions/controlling-english-ivy/?searchterm=hedera%20helix

Horsetail (Equisetum spp.)

While a native plant, it often shows up where it’s just not wanted.  And it is very difficult to control.  So it makes my list.

That’s my “roundup” (pun intended) — my own personal most wanted list.  These rooty, shooty plants that are so insistent, persistent, and resistant… that they ALMOST make you long for Roundup.  The BEST solution is to make sure they never get a firm footing in your landscape.  Having failed that, it’s going to mean your own persistent, consistent resistance.

Dealing with Infested Beds

There are two options that I can see.  Both are a LOT of work.

Method 1

Prepare a (weed-free) holding bed.  Dig up the DESIRABLE plants out of your infested bed/area.  Work their roots over carefully, looking for invaders.  The invasive roots may be in, over, under, around, or through your plant.  You have to inspect very carefully and remove every bit of root and stem.  (Dividing them will help, if that is possible and/or useful.) Plant them in the holding bed. MONITOR them for more weed growth. The best time to do this for minimal impact to your treasured plants is after the fall rains start or during winter dormancy.  Late winter/early spring is fine too, but you are more likely to have an empty bed for the growing season.

With the weed bed “empty”, you can have at the invasive plants.  Dig it or double-dig it, depending on the weed involved – get down as far as you can see roots.  Break every clod up looking for the bad guys.  THEN, once you are “done”, know that you WON’T be done for a month or three.

Check the bed (and your “keeper” plants) at least weekly.  Eliminate any invaders that pop up.  DO NOT let them photosynthesize.  This lets them build roots for another push.  Keep at it.  IF YOU ARE NOT VIGILANT, YOU WILL NEVER CLEAR YOUR BED.  When the bed has been invader-free for a couple or three weeks (more if you are cautious/don’t’ EVER want to do this again), you can begin to transplant your WEED FREE plants back into the original bed.

Continue to monitor.  Your invader will likely have created a store of seeds that may last decades.  This is not really a problem as long as you knock them down as soon as they sprout leaves.

Method 2

Leaving your desirable plantings in the weedy bed, cut down every bit of invader that you can see.  Pick through your desirable plants doing the same.  Monitor the bed every few days, cutting down every bit of invader leaf every time you see one.  The idea (again) is to not let them photosynthesize.  Eventually you will deplete the root and the plant will stop sending up shoots with leaves.  As above, keep at it until you are confident that you have eradicated the invader.  IF YOU ARE NOT VIGILANT, YOU WILL NEVER CLEAR YOUR BED.

Continue to monitor.  Your invader will have created a store of seeds that may last decades.  This is not really a problem as long as you knock them down as soon as they sprout leaves.

Bonus option

No time for all of that?  Then try to contain the problem. Weed the “edge” of the infested area to keep it from spreading. Remove all flowering and seeding tops and dispose of them safely.

DISPOSAL

*****DO NOT COMPOST these plants.*****

*****DO NOT throw them into the forest or an empty lot OR on the beach. *****

Dispose of all plant parts. Leave them sealed in a black garbage bag to cook in the sun, put them in the municipal garbage pickup, or bury them in a deep, deep, deep hole that won’t be disturbed.

And a Last Word:  Keep an Eye on Your Garden — and Your Hanging Baskets!

“Noxious weed” doesn’t necessarily mean the plant is unattractive.  It just means they like to get away and take over habitat from native plants/crops. For instance, Buddleia/butterfly bush and common fennel are on Washington’s B/regional list. Today’s coveted favourite might just become the next invader. Take notice of how many volunteers are coming up in your landscape.  If it’s VERY vigorous in your garden – especially without supplemental water – it might become our next broom or Japanese knotweed.

Watch for the “spillers” in your baskets.  Lamium goleobdon (yellow archangel) is great in your basket.  On the ground it acts quite a bit like ivy, blanketing the ground and choking out native plants.  Ask for baskets without it. Lysimachia nummularia ‘Aurea (golden creeping Jenny) and Ajuga reptans (bugleweed comes in many lovely varieties like ‘Black Scallop’) can be very vigorous. They might not be quite ready to take over the world but you WILL curse them if they make their way into your well-watered lawn.

Note that the BC Government has excellent web resources on noxious weeds.  For information about these and other weeds (cleavers, mullein, etc.), check out:    http://www.agf.gov.bc.ca/cropprot/weedguid/weedguid.htm

Also check out the noxious weeds for Washington state. With climate change, if a plant is bad there, it’s likely just a matter of time before it’s bad here.  http://www.nwcb.wa.gov/nwcb_nox.htm

2 thoughts on “Noxious Weeds in Your Landscape

  1. You have made some really good points there. I looked on the internet for additional information about the issue and found most individuals will go along with your views
    on this site.

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