Plant more vegetables now! Master the wild ride of erratic weather for a perpetual yield in the garden
As the tomatoes give way to endless bowls of salad greens and carrots growing sweeter as the nights grow cooler, the boss level gardener always has enough to share.
Simple in theory. Yet for those of us in the Mountain West, these seasons can be a wild ride. In fact, they are often so sporadic that without a calendar it’s often nearly impossible to pinpoint exactly what season we’re experiencing. Fall in the Salt Lake Valley is usually a “just right” situation sandwiched between a “Lard-a-mercy, it’s still this hot?!” and “Wait, what?! It’s winter already?” Which, of course, is then followed by a long period of “just right.”
This wild ride can make pulling off a successful fall garden challenging. However, sweet success can be yours with a few strategic boss moves. Each of these techniques builds upon the other, so if you’re new to gardening, set yourself up for success by starting at level 1.
Boss move #1. Short and sweet
Many fall crops have a short life cycle, often described as DTM or “days to maturity.” This is the number of days it takes from the time you plant the seed in the ground until your crop is ready to harvest. Crops such as lettuce, radishes, spinach and countless Asian greens can mature in less than 40 days. The shorter the DTM, the easier the crop, as in the more likely you are to harvest it before winter sets in. In fact, these crops are so quick to grow and harvest that you can succession plant them, meaning you repeatedly direct seed more each week, guaranteeing you repeated harvests. Many of these are “cut and come again” crops, meaning they will regrow for multiple harvests.
One thing to keep in mind when considering the DTM of a certain crop is that as the days grow shorter, the plant has less opportunity to gather sunlight energy. This means that it takes longer than the stated DTM. For crops planted in September, add another 20%, and for crops planted in October, add another 30%.
This is important because once the light falls below 10 hours per day, most plants will cease to grow. This is often referred to as the “Period of Persephone,” named from a story in Greek mythology. For us in the Salt Lake Valley in 2020, this is November 12. This is the hard cut-off date for growing a plant to maturity, and in fact one should aim several weeks ahead of this.
Boss move #2. Snack attack, not feeding frenzy
Since our “just right” window is often so short in the fall, we need to make sure our lil’ plant friends have all the nutrient resources they need to grow quickly.
This is a marathon and not a sprint, so don’t overdo it. Plants that are fed too much nitrogen become magnets for pests like aphids, who prefer a high nitrogen environment.
If I am planting transplants I will “water them in” with a dilute solution (half strength) of fish hydrolysate or fish emulsion, plus kelp. If I am starting from seed, I will make this first application when the plants have their first true leaves.
I will continue to feed lightly with this half-strength solution on a weekly basis, then stop once the plants near maturity. It’s a good idea to not apply this solution to any edible part of the plant within a couple of weeks of eating them.
Using this technique for carrots or beets will yield lush foliage but very little root. However, beet and carrot greens are full of nutrition, so you decide!
Boss move #3. Get ready for the heavies and run for cover
Ready to play how the players play? Broccoli, cauliflower and cabbage are the unicorns of the fall garden: We hear of these magical beings, yet they never seem to actually materialize. Let’s face it, a boss-level garden should yield more than leaves and salads. But getting these elusive crops to reach full maturity before the Period of Persephone sets in is beseeched by challenges.
The first problem is these crops have a long DTM. As I detailed in the July issue of this column, these crops must get started in mid- to late July in order to have enough time to set their full heads before the days are too short. So, you’ve either done this successfully (high five!) or you’ll need to purchase starts. Once you have them, they’re ready to get planted out as early as possible in September, but….
It’s too hot. September in Utah can see many days with a hostile sun still beating down 90-degree daytime highs, which is simply much too hot for our tender cool weather seedlings. If we’re going to pull this off, we’ll need to protect them, which means shade cloth. I use 30% shade cloth attached to standard low tunnel hoops to create a cooler microclimate below, which helps keep the plants a bit cooler. If your shade cloth goes all the way to the ground, then this will also keep out the small whites (false “cabbage moths”), which is a next-level boss maneuver.
Once the weather moves into the 70s and low 80s reliably, you can remove the shade cloth, but don’t lose the hoops. Come October, you’ll need to install greenhouse plastic over your hoops to create a low tunnel. The cool weather fall crops can survive light frosts—that’s not the reason for the plastic. The goal is to consistently raise the overall average temperature that the crops experience, the result of which is a much faster growth rate. Be sure to ventilate the low tunnels on hot days so as not to overheat the cool weather-loving plants inside.
When building low tunnels, only ever use greenhouse film, never cheap plastic sheeting from the big box store. Cheap plastic sheeting will phytodegrade quickly, making a mess and also making you less of a classy human being for purchasing one more giant piece of single-use plastic.
Greenhouse film catches and diffuses light, resulting in even plant growth. Take care of it and it will last a decade or more in this application.
James Loomis is a full-time urban farmer, educator and keeper of the Old Cherry Orachard (aka OchO), a permaculture farm. He lives in Salt Lake City.