Managing Garden Weeds
Gardener’s Corner | Questions and Answers with Local Experts
By Dan Songster, 2011 July
This column is a regular newsletter feature offering chapter members and local experts a chance to briefly share information on many things related to gardening with natives. The question for this Issue: “How do you manage, suppress or avoid weeds in your garden?”
Bob Allen-“A triple threat: compost atop the open areas in the gardens, gravel walkways underlain with landscape cloth, and lots of plants.”
Alison Shilling-“Weeds are to quite a large extent suppressed in my front native garden by the coverage of about 3/4 of the ground by perennial plants and shrubs. I do about 1/10th the weeding there compared to the back yard, where I have largely annual vegetables and fruit trees.”
Christiane Shannon-“Most commonly, I use the hand pulling technique and seldom go in my garden without taking the time to pull a few handfuls of weeds here or there. I am very well aware of the importance of pulling them out before they go to seed. Beginning a year ago though, in order to make it easier and faster, I have been spraying Round-up on the worst pest (an exotic spurge) that takes pleasure in popping up everywhere in my pebble paths. It is quite time consuming to get the roots out of compacted pebbles.”
Ron Vanderhoff– “Mostly with a combined assault. My most popular is a wiggle hoe (“Hula-hoe”), hands and knees, and corn gluten. The corn gluten should be used more. It is a preventative, 100% organic pre-emergent and seems to really help, especially after the second season, but timing is everything. You have to put it down a month or so prior to the primary germination period. That will vary depending upon whether cool season or warm season weeds are the target or both. It has no impact on soil ecology, groundwater contamination, or plant health.”
Dori Ito– “1) Mulch 2) Mulch 3) More mulch 4) Commit random acts of weeding. 5) Try not to water anywhere I haven’t mulched.”
Laura Camp-“I usually hand-pull, but I do use Round-Up on occasion, in pathways and on my DG surfaces. I have a terrible problem with an onion-like weed that I don’t know the name of. Years ago I read a recommendation by Robert Smaus of the LA Times that the whole plant plus all the dirt around the bulb must be removed because the dirt-colored bulblets will just make a new plant. I have found this impractical, and the weed just seems to proliferate when I try to weed it. This year I have worked on removing the leaves as soon as possible when they show above ground, and that seems to be working to starve the energy of the bulbs. We’ll see if my strategy works long term.” (I hope it is not Asphodelus fistulosus – that is a tough one-Dan.)
Alan Lindsay-“For large bare areas I’ve used landscape cloth with a layer of bark on top (just to hide the cloth). Both are easily obtained. The bark and cloth should probably be replaced after 2 years but I’ve had it down in one area for over 5 years. One advantage, which can also be a disadvantage, is that the ground will stay moist under the cloth that does affect the root system of plants nearby.”
Chuck Wright-“PERSISTENCE. I trust the Bradley method, of pinch and pull. Mulching helps, I prefer rock, but organic mulch works too. My favorite tools are a large screwdriver and a small screwdriver. For really nasty weeds I cut at base and apply a few drops of Roundup, but this is a last resort. A kneeling pad is a must.
Sarah Jayne-“Fortunately, in my home garden, I have very few weeds. The school garden I maintain is another matter. There, it’s mostly staying on top of things with hand pulling (which I actually enjoy), and an occasional chemical treatment on the oxalis by the school district landscape department.”
Rob Moore-“First and foremost Mulching. I areas where this isn’t feasible like the wildflower meadow in my backyard, hand pulling is the norm-especially with the more woody types like Horseweed. I use Roundup with the softer plants such as Dandelions and Sowthistle. I treat them in late fall/early winter before the wildflowers emerge, after which, I return to hand pulling. Nut Sedge is a bit more tricky as I’ve had no luck using Glyphosate with this plant. I have had some luck laying down newspaper and a layer of mulch, but this only mitigates their inevitable appearance. Argh!”
Dan Songster-“For me it depends on whether it is a supper weed or just a normal garden weed. For “superweeds” like Bermuda Buttercup, Bermuda Grass, Nutgrass (Sedge), and Field Bindweed, I use systemic chemical controls like Roundup. If they are growing amidst desirable plants I sometimes wipe the diluted herbicide on the weed leaf to avoid any spray drift. Weeds of the common variety may seem tenacious and difficult but they are weaklings compared to those superweeds and so hand pulling (“grab low and pull slow”) and then a thick layer of mulch will do the job just fine – I try to get to them before they drop all their seed though.”
Celia Kutcher– “My native garden replaced a bermuda lawn that sprayed out some weeks before beginning hardscape and planting work. So, many weeds & their seeds were pretty much
eliminated before planting. In the 20+ years since then, diligent hand weeding has kept them eliminated. My main weed problem continues to be non-native annual grasses. Since they sprout & grow so quickly after the first rain, IF I manage to get after them right away they are easily distinguished from resprouting Nasella & wildflower seedlings. But if not, there’s always some that I don’t see until after they’ve seeded, & there they are again next spring.”