Yesterday I wrote about my ongoing process with removing oxalis, which is a big job this time of year. A little earlier, through March and April – the local season of Djeran (autumn)-, I was working on brome grass. Greater brome has no particular use to me. It’s growing thickly around the lemon tree where it interferes with the root system, and it’s not doing a great deal for the soil except trapping some organic matter at the very surface (as most annual grasses do). The seeds are a potential hazard to animals and the leaves don’t make great feed due to their high silicon content. The best use I could come up with for it was as green manure, and “brown” (high carbon) compost filler.
When I first moved in I weeded out a lot of the brome grass, not knowing exactly what it was. The one area I didn’t weed out has been a serious thicket of it since, and has grown harder and harder to clear as the “wanted” plants grow through the area. So this year I tried an autumn-tickle-style approach. In early March, while it was still secondsummer and regular good rain was months away, I lightly disturbed the soil, providing a small amount of fertiliser and various nutrients that I’d planned to give the lemon tree anyhow. And then I soaked the area well with a good sprinkler. The idea was to get the brome grass germinating ahead of everything else that would want to germinate when the soil cooled a little further, so I’d be able to take it out on its own by weeding or just sheer drought.
This was about half successful. There was a huge amount of seed germination, but it was spread out over about a month. While brome can have a staggered onset, I think I could have got more of it germinating in the first instance if I’d added something to the watering to break the soil’s water repellence down as some spots just didn’t get the water to any depth til a month later. So while I weeded out a lot of young growth initially, and then again, and then again, leaving it all just on the surface of the soil to break back down into humus, I by no means got it all. And the lack of water after the initial trigger didn’t bother it particularly. I’m hoping that another round of weeding soon, with the grass more developed but while it’s still too cold for it to be forming seedheads, will take out the worst of it. Brome grass doesn’t have as short/non-existent a dormancy as oxalis, but its seed doesn’t tend to survive more than two years and tends to germinate at the first opportunity. So knocking it back badly in one year will make a very noticeable difference to what comes up next year. It certainly did the first year. I do need to stay on top of it for two years in a row to get it gone though.
I also did get a number of “wanted” annuals germinating, mainly buckwheat and nasturtium, but I accepted those as potential losses. The nasturtium seed stock in the soil I knew would be high enough that if I lost some, there’d be others coming along, and there would certainly be volunteers I could move from other spots. The buckwheat I managed to keep from killing off long enough for it to set seed, so I may see some there in spring. It didn’t like the drought though, it was more sensitive to the water-once-then-nothing-for-weeks than the brome grass was. I am happier losing it now though, and replanting seed in spring, than I would be not getting at the brome grass. The long term idea is that this whole area is low-care, with me having to do nothing but pull an occasional weed here or there, and everything else that germinates being a useful contributor to the system. To do that, I need to remove the brome.