Most people love the idea of creating a native wildflower meadow in their yard.
There’s one primary problem, however, that often defeats the process – non-native weeds and grasses.
The criminals? Some registered offenders include bur clover, with those nasty, little coiled balls; Bromus, with its foxtail-like stickers that find their way into your socks and dog’s ears; filaree, with corkscrew seeds that wind through clothing and into the fur of your pets. These invasive species are everywhere because they’ve adapted to soil disturbance and the semi-arid Mediterranean climate that characterizes California.
Clear an area, throw out native plant seeds, wait in anticipation, and before long, the entire area is filled with nasty things that seem to cover the ground over night.
Fortunately, there’s hope. And we think we have found a successful recipe, at least for our corner of the world in northern San Diego County. Patience and perseverance is required.
We have successfully restored about a quarter acre of suburban yardom to a fully functioning native habitat with nesting birds, native bees, harvester ants, and a new surprises discovered weekly. Here’s how we did it.
A. DO NOT DISTURB THE SOIL by turning it over, as is the usual agrarian approach to growing things. Keep the soil crust intact. If it’s loose, watering and walking on it a bit will help start the restoration process. You could also use one of those water filled rollers people employ to smooth the ground prior to planting a lawn.
B. DO NOT USE MULCH. Covering the soil with mulch will prevent a healthy soil crust from forming and can facilitate weed growth.
C. THE ECOSYSTEM APPROACH. The basic message here is that you want create a functioning ecosystem that is self-sustaining. This means creating and maintaining an intact soil surface crust that can eventually be home to tiny mosses, lichens, and a whole host of arthropods, including native bees (many which make burrows in the bare ground) and red harvester ants. You’ll also want to create habitat layers as described below (D). AND you’ll need to do the best you can to eliminate non-native Argentine ants from your habitat. Argentine ants not only kill native insect species (especially harvester ants), but can also kill your native plants. This task is definitely a challenge, but it can be accomplished. We have the recipe for how to do so here.
A healthy, native habitat will attract tremendous biodiversity, and as a consequence, will increase your life span and the joy you get out of each and every day.
D. LAYERS OF SHRUBS. You’ll want to create several layers of habitat. This means that along with the wildflowers, you’ll want add additional plant layers. Start with low-growing shrubs like sages (black, white, Cleveland, etc.). Then create mid to upper layer habitat by adding a few larger shrubs like manzanita (Arctostaphylos refugioensis is one of the most dependable, fastest growing species) and Ceanothus. Toyon, laurel sumac, holly-leaf cherry, lemonadeberry, and mountain mahogany can be used as stunning, specimen shrubs, but make sure you have the room as they can grow quite large. We obtained our native shrubs from our friends Mike Evans at the Tree of Life Nursery and Ryan West at the Native West Nursery. The Tree of Life Nursery also has a remarkable list of suggestions on how to plant and care for your native shrubs so you don’t love them to death.
1. STOP NEW DEPOSITS INTO THE INVASIVE SEED BANK
Use a weed eater and/or a mower once the weed crop is up and growing, but BEFORE the seed heads set after the winter rains. Late February is a good time. Collect as much of the cut material as possible and send it away with the trash. Do this again in late March. Ironically, most of this kind of thing is done in May or June, after the seed heads have set and are ready to go. As a consequence, the seeds are spread all over the place. Seems obvious to us, but then humans often repeat the same mistakes over and over.
2. HALT THE SEED BANK WITHDRAWALS
Let weed seedlings coming out of the soil seed bank grow for a couple weeks, then initiate stage two of the attack. The best method is to spray the little green invaders with your choice of weed killer, avoiding the soil disturbance that comes with pulling them out. If you don’t want to use Roundup, one organic option that reportedly works well is one provided to us by our friend Jefferson Wagner:
1/2 gallon apple cider vinegar
1/4 cup table salt
1/2 teaspoon Dawn liquid dish soap (blue)
Mix well prior to dispensing and pour into your hand-carry or backpack sprayer. It’s a good idea to let the bubbles settle before spraying – they can clog the the sprayer. Spray baby weeds thoroughly. Saturate them! The recipe makes 1/2 gallon for around $6.00. The Dawn dish soap strips the weed of its protective oils so the vinegar can work with deadly force. The KEY variable here is that you need to use this mix when the weeds are still little seedlings.
3. HIT THEM AGAIN
In early to mid May, roam your yard and hand pull any large weeds that have survived the first attack. Do another spraying to go after the warm season weeds, especially bermuda. Recon your yard all summer and spot treat or pull any sneakers.
THE KEY is to stop the weeds from seeding again.
4. MOP UP!
After the next winter rains, hit newbie weeds that are emerging with your favored spray, usually by mid February.
Distribute your native seed. Don’t over do it. We used 3 pounds of three seed mixes for a quarter acre from S&S Seeds. Note: their Insect-Flora Mix has a lot of white alyssum, which isn’t native, something we didn’t want, and don’t understand why it was included – so double check the seed list to avoid that one. We’ve listed the two seed mixes below that did not include alyssum. The Tree of Life Nursery also has batches of native wildflower seeds.
PLEASE, avoid using those “native” wildflower mixes in little envelopes from Home Depot or other retail outlets. The seeds are actually an assortment of non-local species along with native look-a-likes.
As our friend Greg Rubin (a remarkable native landscaper) recommends, do a light “dusting” of DG over your seeds – Decomposed Granite (available from your local dirt/rock yard dealer). This will keep your native seeds from becoming an expensive seed mix for the local birds and will help settle the seeds into the soil. A couple pick-up truck loads was enough for our quarter acre area, but you might want to just order a cubic yard. The extra can be used later to construct a native garden path through your wonderland.
The amount of supplemental water you’ll need will obviously depend on how much rainfall you’ll get the year you plant. The objective is to keep the ground moist (not soaked) to get your seedlings up and running and able to get through the spring. We stopped supplemental watering this year in late March. Note: rainfall this year was remarkable, which clearly helped our results.
8. CONSTANTLY ON GUARD
Non-native weeds WILL re-invade despite your best efforts, mostly from your neighbor’s yards. During your daily walks through your restored native habitat, be on the alert to discover any sneaky weed, especially the noxious kinds (Bromus, bur clover, filaree). Rip them out and put them in the trash. STOP THE SEEDS before they get a toehold again.
Below are a few photos of our project. Enjoy!
These are the two seed mixes we used and recommend from S&S Seeds:
Coastal Sage Scrub Mix
Use this mix when native scrub restoration is desired. It is a blend of grasses, flowers and shrubs for re-vegetation of soil and slopes with plant types that belong here. There is a quick start grass to protect soil and allow slower perennials to provide their permanent cover in the years to come. Designed as a non-irrigated mix, irrigation will foster establishment and prolong the blooming period.
Height range: 12-54 inches
Price per one pound: $60
Chaparral Sage Scrub Mix
Use this mix when native chaparral scrub restoration is desired. It is a blend of grasses, flowers and shrubs for revegetation of soil and slopes with plant types that belong here. There is a quick start grass to protect soil and allow slower perennials to provide their permanent cover in the years to come. Designed as a non-irrigated mix, irrigation will foster establishment and prolong the blooming period.
Height range: 12-36 inches
Price per one pound: $60