Las Pilitas Nursery

California Native Plants are all we grow!

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3232 Las Pilitas Rd
Santa Margarita, CA 93453

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This website is dedicated to Bert Wilson. His genius continues to inspire us.

Weed Control

The lesser of evils.

Weeds are part of the climate change problem. Weeds contribute to desertification, lower rainfall, releases of CO2, methane and replacement of native fauna with nasty animals like Starlings and rodents. Weeds contribute to lyme disease, the drying of water wells and the siltation of our waterways. Weeds change the fire frequency from 100-500 years to months. Fireman die in grass or weed fires, not native wildland fires. Weeds create an alternate ecosystem that supports nothing, which favors more weeds and the destruction of habitat. There is nothing good about weeds, why do people worry about killing them?

If you don't control the weeds first, it is difficult to grow a native garden. The higher the weed quantity, the lower the wildlife quality. Wildlife gardens should be maintained weed free. - grid24_12
With weeds
weeds suck - grid24_12
With more weeds

Weeds have evolved for thousands of years with us. Most of our activities favor weeds. Disturbing the soil with tilling or disking favor weeds. Fertilizer favors weeds. Watering favors weeds. Soil compacted by vehicles, our ditches, pollution, and plastic favors weeds.
Those plastic weed barrier products favor weeds, our native plants have died under plastic 'mulch'. I suppose if you aired out the plastic for a month or so before using it the natives might be ok with it. Plastic Landscape fabric has not worked very well in any landscape we've seen. In the nursery we use the landscape fabric on gravel in the greenhouses, but we have to drag them out and shake them off, or sweep them off every year or so. The dirt builds up on the surface and weeds get established on top of them, weeds grow through them, weeds grow under them, lifting the plastic.

The soil-mulch interface is where a number of the soil building, root activities, and weed suppression occur. Putting plastic in this interface. I cannot understand how plastic landscape fabric can fit into an ecosystem. Weeds are bothered by it, good plants are killed by it.
Clear plastic has been used to sterilize the soil with solar heat. It does a great job of killing most everything in the top ½ inch of soil, including the good guys that help suppress weeds. So the next year you have huge juicy weeds. Definitely don't put solid plastic around already established plants it will cook them or suffocate them. Putting the plastic down with bark or chips has been the pits! After a few years the bark breaks down and the plastic is exposed, the plastic breaks down and peels back. So, use the plastic if you like a yard of weeds, plastic pieces that look like shredded garbage bags, with unhappy or dead plants in it. Maybe an old car on blocks could complete the theme.

oak tree shreddings work well for mulch - grid24_12
Forget the plastic and use more wood or rock mulch. Good mulch can suppress many types of weeds.

Cultivating favors weeds. You can control weeds with cultivation, but it takes longer and you'll have to be more diligent. First remove any weed you slice, shovel or hoe. Garbage bag them and physically remove them from the scene. Leaving the debris favors more weeds.
Mowing or weed eating is not weed control. At best mowing can slow down the spread of weeds and the destruction of habitat. At worst you're spreading the weeds. The lesser of evils, weeds are bad, hand removing every weed is bad and sprays are bad. As Lou Costello said, "I've been a bad boy."

There are weed killers that kill grasses,(Fusilade, Poast),  some kill thistles (Transline), some are called preemergents and they stop weeds from germinating,(Surflan, Ronstar, Gallery, etc.). Timing is important for chemical weed control. Proper use is also important. Follow the label and use only what you need. The grass killers need actively growing grasses, spray late and they do not work, or work poorly. If the weed has set seed, (finished flowering) even if it is still green, you're too late for sprays.  Preemmerents work before the weeds germinate and they only last for about three months. Preemergents need at least a 1/4 inch of moisture after application. So, preemergents should go down before first rain, or at planting time.

use rock mulch for native desert garden - grid24_12
Mulch can suppress many types of weeds. Use rock for desert species.
Nature abhors a vacuum. Bare ground allows for weeds. Mulch helps. The right mulch for the site suppresses weeds. But the right mulch combined with the right plants for that soil and plant community REALLY suppresses the weeds. Plants+mulch is ten times stronger than just mulch, mulch is six times stronger than bare ground. You can redeem yourself, plant back plants for the wildlife.


Learn your weeds. Learn your natives. Kill the weeds. Plant the natives.

Ok. Now pick a defensible area that you think you can control, mulch and plant. If you can't do the whole area, pick a smaller area. Prioritize, be reasonable on what you can do, and budget full resources to do it well. Better to do a smaller area well expanding gradually over the whole area than a large area poorly, every year, for twenty years. It's like painting a house, use the good paint to paint a room at a time, don't dilute the gallon of paint and paint the whole house, tacky?


Work real hard to make the area look like a dream park. In a few years it will.

For every weed you allow to set seed you will have thousands more weeds.

A few of the thousands of weeds. This are some of the real pains.

Weeding is awful. Spraying is awful. Weeds are awful.

Red brome and Fileree are both nasty weeds. - grid24_12
Annual Grasses. For most of you, if it's an annual grass, kill it, it's not native. Grass Killers and preemergents both work well. But both have to be used early, not after the heads have appeared. Here is Red Brome with Filaree. Both favor each other.
For most of you, if it's an annual grass, kill it, it's not native. Grass Killers and preemergents both work well. But both have to be used early, not after the heads have appeared.
Filaree (Erodium cicutarium) is a awful weed. We have no good controls to offer.  - grid24_12
Filaree favors Filaree and other nasty weeds.
What a nasty plant. If filaree gets a hold of your yard, times be bad. Very difficult to control, you can try preemergent and a shovel (cut off 1/2-1 inch below the surface) for what comes up. We've hand cleared acres of the stuff. The pigs love it. Hey, that's a thought. Maybe you could raise pigs in the back yard? The barbecue is right there.
Euphorbia peplus (petty spurge, radium weed, cancer weed, or milkweed) is a nasty weed - grid24_6
Petty Spurge. A real pain, a general spray kinda works, preemergent kinda works. You'll end up hand weeding, might as well start that first. Just remove it from the premises.
The clean areas were not seeded. The areas that look dead and highly flammable were seeded. Not looking at past  studies and short term thoughts make for a mess like this.  - grid24_6
"California Brome" is great marketing, absolutely an environmental disaster when seeded after a fire .
The dead grass is just like the same weed in your garden that burns like a dry Christmas tree. The green areas are real native plants.
Goosefoot is a edible weed. - grid24_12
Goosefoot. Fat Hen, Chenopodium album. Easily removed with a shovel.
Mallow weed, we only got it under control with mulch.  - grid24_12
Little mallow, Cheeseweed, Malva parviflora, another pain. Preemergent and mulch. Mallow hates good mulch. Very difficult to cut out with shovel, like cutting rope.
Black mustard is a nasty weed that you probably will have to cut off just below the crown. Tedious, but it doesn't come back. Remove the debris, the green, immature seeds will germinate. THIS IS NOT A NATIVE PLANT! - grid24_3
Mustards,Brassica Cut out with shovel. REMOVE the mustard debris.
Scarlet pimpernel weed - grid24_6
Scarlet Pimpernel, Preemergent, hand pull.
Sow thistle weed - grid24_12
Sow Thistle, Preemergent works well. Cows, horses and pigs love it.
spotted spurge is one of those weeds that you have to hand pull. WHAT a PAIN! - grid24_6
Spotted Spurge. Every node sets seed. Control the Argentine ants as they spread it. Preemergents help. Hand weed. You can try spot spraying, but they seed back constantly if you do not remove everything by hand.
Rabbit tail grass makes the dogs cough for hours. - grid24_12
Rabbitsfoot grass, Polypogon monspeliensis requires immediate hand removal if you find. Dogs eat it and hack for a day or two afterwards.
Tall annual willow-herb, Epilobium brachycarpum, (Epilobium paniculatum) may be native to California, maybe not, it is so aggressive that really should pull it if you see it. - grid24_6
This small flowered Epilobium, Fireweed, is a very aggressive native. The fireweed with pretty flowers is much more a normal garden plant..
Sweet Alysum (Lobularia maritima) is native to the Mediterranean area and east to Armenia, North into France. Sweet Alysum is an annual mustard that can cover large areas with its weedy habit, then die in midsummer.  A ruderal. - grid24_6
Sweet Alysum (Lobularia maritima) is included in many 'wildflower' mixes. Try to get rid of it and you'll hate the companies that peddle it.
Pineapple weed(Matricaria matricarioides, Lepidotheca suaveolens, Chamomilla suaveolens)  - grid24_6
Pineapple weed(Matricaria matricarioides, Lepidotheca suaveolens, Chamomilla suaveolens) is related to chamomile which can also be a weed in many areas. Favors bare ground and disturbance. So mulch and /or leave area alone.
Cortaderia selloana , Pampas grass. Vandenberg had 2 plants in 1980, 100,000+ in 1995. - grid24_6
Why would anyone plant a five foot weed that seeds itself everywhere and you need a backhoe to remove? Cortaderia selloana, Pampas grass, mixed in with another nasty, Veldt Grass.
Sow Thislte, Sonchus oleraceus, differs from a Dandelion in that it has leaves up the stem. - grid24_6
One of the Sow Thistles, Sonchus oleraceus, differs from a Dandelion in that it has leaves up the stem.
Gnaphalium luteo album, Weedy cudweed. - grid24_12
Weedy Cudweed is slowed down by mulch and drought.
Bromus madritensis, Foxtail - grid24_3
Bromus madritensis, Foxtail can be controlled with mulch, preemergents or grass sprays.
Yellow Star Thistle, Centaurea solstitialis - grid24_12
Yellow Star Thistle, Centaurea solstitialis is fairly easy to control with a spray right as the flowers show. Follow up with a mow down and it pretty much disappears.
Centaurea melitensis Tocalote is smaller than regular star thistle, harder to control. - grid24_6
Centaurea melitensis Tocalote is harder to control as it sets a flower at its base very early.
Bur chervil, Anthriscus caucalis - grid24_12
Bur chervil, Anthriscus caucalis is one of the up and coming weeds.
Oxalis , Wood sorrel weed - grid24_12
We used to call it Woodland Sorrel. Now we call it %$#@@oxalis. Hand dig out every root.
Groundsel, Senecio vulgaris - grid24_6
Groundsel, Senecio vulgaris is one of the most common weeds in the world.
Veldt Grass, Ehrharta calycina - grid24_6
Only a few of you that live near the coast in sand know this one, Ehrharta calycina Veldt-grass. Spray.
Convolvulus arvensis, Filed Bindweed - grid24_6
Without cultivation, Field Bindweed, Convolvulus arvensis, is a minor nuisance.
One of our test plots on the hillside trying weed control. - grid24_12
Over the years we've experimented with sprays, grazing, mowing, hand pulling. They all suck, all work a little.
Nutsedge, Cyperus is a nasty weed in ag fields. - grid24_6
Nutsedge is considered native, but it is an aggressive weed where there is water.
Conyza canadensis, Horseweed is resistant to glyphosate.  - grid24_3
Horseweed, Conyza canadensis is the newest weed to conquer California.

Some simple books for Native plant id.

Belzer, Thomas J.. 1984 Roadside Plants of Southern California, Mountain Press, Missoula
Dale, Nancy; 1986, Flowering Plants, The Santa Monica Mountains Coastal & Chaparral Regions of Southern California, Capra Press, P.O. 2068, Santa Barbara, 93120 

Kozloff, Eugene N., and Linda H. Beidleman. 1994 Plants of the San Francisco Bay Region. Sagen Press. Pacific Grove

This one has natives and weeds since it looks at it from a cattleman's lens. Just look up the plant on the net and find out if it's native and a high value wildlife plant before you decide to kill it.

Whitson, Tom, et.al. 1996. Weeds of the West. 5th edition, pioneer of Jackson Hole, Jackson Wyoming.

Also, if you really get into it, see if you can find a flora for your county and take a Taxonomy class.

Bromus tectorum, (Anisantha tectorum), Cheatgrass Downy Brome June Grass - grid24_12
Cheatgrass has taken over vast areas of the west. It burns like gasoline creating a bed for more cheat grass. This is why vast areas of the desert and forest that used to burn every few hundred years, now can burn every year.