Perhaps some others in SLO County have been experiencing the same frustration with extra weeds this year of rain. The weather station at www.sloweather.com (located on a hill above Laguna Lake)reports 34.7 inches of rain since July 1, 2009.
I have a few ideas - having asked a few folks what they do, what they suggest.
Pulling seems to work best when the soil is moist, any other time it seems hard to get the entire root system, especially for some types like dandelions. Anyone for goats or weeding geese? Do these critters actually know which are the weeds? They are reputed to go for the grasses not the board leaves - won't work for me as most of my weeds have broader leaves than the natives I've planted.
My friend Ruth has a wonderful California Native garden in Los Osos. She has a gorgeous modern home that seems to be built on dunes that are alive with salvias, buckwheat, ceanothus, oaks and other vegetation waving in the ocean breezes. Not many weeds though. She reports that they used an herbicide at first, and a pre-emergent to prevent seeds sprouting. It's not 100% for her, but helped a lot.
Many with an ecological bent might be unwilling to use an herbicide, but Bert Wilson, of Las Pilitas Nursery told me that I would be sorry if I didn't use one (after I told him the whole backyard I wanted to plant in natives was nothing but weeds). Do I? Some days for sure.
John, who owns a business that does design, planting and maintenance in California Natives, suggests going first for those plants about to set seed. Worth keeping an eye out for this, if nothing else works.
Mike, who also owns a business doing design, planting and maintenance in Mediterraneans as well as natives uses cardboard and carpet scraps in a rather creative way. Where he wants to place plants, he rakes up the weeds at least, then lays down large cardboard pieces (think refrigerators and other appliances). The mulch goes on top, but the planting happens around the same time so I assume he doesn't have to cut into the cardboard. As you can tell, I haven't watched him do this, but a garden I see weekly is though not weed free, a whole lot better than my yard, and it gets a lot more water.
I dry creek bed I made was getting weeds, I once asked Mike what he does with creeks, since I feared that cardboard wouldn't be effective enough. He said he uses carpet that he finds discarded in the dumpsters behind carpet stores. Sounds like a good way to recycle extra carpet.
I have heard that boiling water, with or without vinegar kills weeds. This might be useful on a patio or cracks in sidewalks. I understand this works better on hot sunny days. I think it takes ongoing treatments though.
My husband has his own method using a propane tank wheeled around with a torch. I'm not too enthusiastic about this method as I don't believe it kills the roots of the weeds. It works short term on a patch of white rocks, but is less effective on a patio which looks even worse after treatment than before.
I tried corn gluten meal (pre-emergent) one year at another yard. It didn't do much that I could see.
Nitrogen in excess seems to promote weeds, whereas nitrogen fixing plants such as ceanothus, alders and legumes such as California sweet pea, provide nitrogen more slowly so are not so likely to encourage weeds as much.
What works for you?
