This is part of our hillside cactus plantings. These particular plants are about two years old and will start to yield well this year.
Over the winter we let the native and introduced grasses grow with the winter rains. The common nature of these grasses is to grow in the mild winter temperatures, with the occasional large storm and rains coming through nourishing them through the winter. In the springtime they put out their seeds and go dry, turning to straw/hay. We let them grow in the winter, and in the spring when the cactus starts to stir from the warmer days, and the grasses have set seeds, we cut them down. This turns the bare stalks and grass leaves into a straw mulch on our soil. This mulch will rot down into the soil through the years, enriching the soil by adding humus to it. This humus is eaten by the microbial populations which exude acids that etch the soil mineral particles, releasing the native fertility of the soil. Basically, we let the ‘weeds’ grow in the winter time to be a ‘green manure’ for us, but we let it seed and go dry , this ensures plenty of good seeds the next year, to keep our grass growth strong, and the dry leaves shatter easily when the machine cuts them…. it saves on plastic trimmer string, fuel, wear and tear on me and the machine. I don’t need to reseed the grasses, I don’t need to water them, they are native and grow well in this alternating cycle of wet-cool winters and warm-dry summers that their seeds must stay alive through in the straw mulch.
You can see in the photo above that the grasses fairly cover the cactus….. most commercial plantings of anything would not let ‘weeds’ grow unabated for five months of the year…. but for us these grasses have more value than as mulch… in the winter we often get a lot of rain, and cactus can rot if it gets too much water in the winter when the days are cool…. the grasses have invasive roots that open the soil in their wanderings… they don’t ‘steal’ water form the cactus, they ‘remove’ excess water from around the cactus, and they keep the soil open and loose so it will drain well.
The grasses buffer the soil, like a carpet, so when I walk through in the winter checking the plants, I don’t pack muddy soil together…. and I don’t track mud all over either.
The grasses cover the soil reducing erosion, compaction, and freezing of the soil. An uncovered soil is much more likely to free on clear open night when the cold of space projects straight down. The grass hovering over and around the cactus also shields the cactus from this frost.
The photo below shows the cactus patch after being weed-wacked with a hand-held string-trimmer machine. There will be some hand clearing done afterwards…. I don’t like to pull the grasses on this slope, I want the roots to stay in the ground, holding everything in place well. So cutting by machine is the best option.