September garden tasks (Zone 7/Southern Plains)
Ahh, September. Admittedly, I'm sitting here humming the Earth, Wind and Fire tune as I begin typing this. I'm also in shock that September has already arrived! The oppressive heat and drought we are used to in the summer was later arriving than usual so it feels like this summer has been especially short. Not that anyone is really complaining.
Here in the southern plains, September is when our second cool season begins. It's still warm by most people's standards, but we've broken the oppressive heat that prevented most of us from doing much more than harvesting and watering since early July. For those of us who limp our spring planted tomatoes through the heat, we can expect to see them begin setting fruit again. Tomatoes planted just for fall should have gone in the ground in early July and will finally set their first fruits. Bell peppers typically pick back up quickly too.
The cooler temps also mean the work picks back up. Here's a list of what I'll be doing:
Adjusting drip irrigation: Oklahoma is known for it's unpredictable weather, so I'll have to wait and see what happens. Being an El Nino year, we're expected to have a cooler and wetter fall but forecasters said the same thing about summer and we ended up with desert-like heat and a flash drought. Because most of my garden is in containers, I'll most likely continue watering daily but adjust the length of time the water runs. If it is wetter than average, I'll shut off the timer but leave the lines set up, running them manually as needed.
Plant the plants: I have several plants started in trays already because the air and ground temps were too warm to consider direct sowing at the appropriate time. I'll begin putting those in the ground. Three things will determine when they're planted:: temperatures, space is cleared, and seedling maturity.
Sow the seeds: Temperatures have cooled enough that I'll direct sow those things that like the coolest ground temps. Those include: additional rotations of radishes, spinach, fast growing lettuces/mesclun, arugula, cilantro, and peas.
Plan for rebuilding raised beds: My heavy clay soil forces me to grow edibles in containers. I've been using repurposed pine shipping crates for the last 4-5 years and their age is showing. My largest and the one where I grow the majority of tomatoes will likely be destroyed by winter freezes. I'm growing fall green beans there and will dig out all the soil once the first frost kills the green beans. This means I'll need to plan for a space where I can store the soil on top of a tarp until the bed is rebuilt. We don't have a pickup truck either so we'll have to purchase materials when we can borrow a truck. This makes it a bit of a juggling act that has to be coordinated with extra planning.
Rain garden work: This was supposed to be a spring project but our extremely wet spring prevented virtually any work from being done. To be honest, fall is the best time to start many of the native plants that will go in this bed, so Mother Nature may have done me a favor. The wet weather made it glaringly obvious how badly this is needed. It will help address drainage issues by properly grading a spot that has filled in with sediment and by giving water a place to soak into the soil as it slowly drains. My dogs are generally good about staying out of gardens once plants are established. In the long run, the rain garden should also mean fewer muddy paw prints on the floors.
Cleaning/clearing: I'll clean as much as I can early in the season and then leave the rest of the spent plant material until next spring. If I don't get something cleaned early enough, it causes me to worry about disturbing overwintering insect sites which makes this is something I'll have to stay on top of this month.
Soil building and composting: This is a 365 project but some early fall specific tasks include setting up a new leaf collection site or clearing out the one I used last year. This year, I plan to move my site. Once I got down to the last six inches of the pile, Bermuda grass found its way in, and I don't want to transfer Bermuda to the gardens. I have a hard enough time dealing with the grass that creeps in on it's own. I'll also be processing branches and limbs from fall tree pruning. Small stuff will end up in the compost bin or piled to the side so it can be added later. Limbs that are too large for the compost tumbler should be just right to save for the fire pit. I don't anticipate any pieces too large for the fire pit, but any that are will be stored out of the way and buried in the rain garden as work progresses there. As they break down the limbs will provide nutrients and serve as organic matter. They're also great for water retention as they decompose. Research has shown that the nitrogen is only tied up where the soil and tree make contact, so I don't worry about that. However, if my soil was lacking nitrogen, I would proceed more cautiously.