Fall Keyhole Garden Flip
Replacing summer’s crop with cool season veggies to keep the keyhole garden producing year-round
It’s mid-autumn and here in San Diego County, the days are still warm and dry, but the nights now have a definite chill.That’s all supposed to change with the first Pacific storm of the season arriving mid-week. After that we’ll switch to late-fall weather – cool days and chilly nights – that takes us into winter.
Knowing what’s coming, now’s the time to clear out the last of the late summer / early autumn vegetables in the main garden and prepare those beds for their long winter’s nap.
There will be no napping for the keyhole garden though. For the fifth year in a row, that trusty (and incredibly productive) raised bed will be running year-round.
Over the course of the next several weeks we’ll swap out most of last summer’s tomatoes, peppers, and bush beans for winter veggies like cauliflower, broccoli, onions, lettuce and spinach.
I say “most” because we’re going to try and keep one Valentine tomato plant, and a handful of the bell pepper plants going over the winter so we have fresh tomatoes and peppers early next spring.
I’ve written before how to keep pepper plants growing year-round, and these bell peppers have actually already weathered one winter, so I’m not really worried about them. The Valentine tomato, on the other hand, is new, so I’m not sure if it will make it or not. Fingers crossed.
Seed Starting
The trick to keeping the garden going through the transition from warm season to cool season is rotating out the old and moving in the new early enough that they get their roots established before the weather gets ugly, but not so early that they try to flower just as the winter weather peaks.
Our preparations here in Zone 9 began back in late September when I planted broccoli, cauliflower, and onions from seed. Those plants like to germinate in warm-ish soil (above 60°), so we start them in the greenhouse. If you don’t have a greenhouse, a sunny window in the house will do just as well.
For plants that prefer to germinate in cooler soil (45° or so) — lettuces, spinach, cilantro, etc. — it’s better to off on starting the seeds until the last half of October when the nights are longer and cooler.
Ready the Keyhole Garden for the Cool Season
When planning for crop succession it’s important to know what germinates quickly versus what likes to take its time because it will affect what goes where in the garden.
For example, brassicas (cabbage, cauliflower, broccoli, etc.) and lettuces germinate very quickly – 7 to 10 days — while spinach, onions, and cilantro can take up to 20 days to sprout.
As a result, those quick sprouters will be mature enough to transplant into the garden in November where the more leisurely ones won’t be ready until December.
Knowing this, it’s not necessary to clear the whole bed at once. Taking it section-by-section not only makes it easier to inspect the bed and make any fixes needed. It also makes it easier to top off the bed with fresh compost from the center bin, which is large enough to fill a section of the bed, but not big enough to reload the whole thing all at once.
Keyhole Garden Fall Transition
Transplanting to follow the Sun
The transition into winter means the days will be shorter and the sun lower in the sky, so you need to pay more attention to what gets planted where to ensure your vegetables get enough light.
For example, our keyhole garden faces southwest and the house sits behind the garden, shading it from the rising sun until mid-morning. Once the sun comes over the house, the southern and western portions of the bed will receive 6 – 8 hours of sunshine, while the eastern and northern portions will only get 4 – 6 hours.
Fortunately, even with the 4+ hours of sun, the northeastern portion of the bed will receive enough sun for many winter vegetables. It does, however, change where the taller and wider plants go versus the spring and summer.
In the warm season, when the whole bed is in full sun for 10 – 12 hours, we use a circular planting pattern with the taller, bushier plants in the center of the garden around the compost bin. In the center they’re still easy to reach and they don’t block out the lower growing veggies we plant in a circular pattern that radiates out to the edge of the bed.
In the cool season though, the lower sun means taller plants will shade the shorter ones if we plant around the circle. So instead, we plant the veggies in wedges like a slice of pie. The shortest plants (usually lettuces) get the southwestern-most wedge, taller plants like spinach and onions get the south and western wedges.
The tallest and bushiest plants – broccoli, peas, etc. – go into the northern and eastern wedges where they can reach upward for the winter sun without shading the low growers in front of them.
Vegetables aren’t as robust growers in the cooler, shorter days, so you can plant them a little closer together than you would in spring or summer. That maximizes the amount of food you can harvest throughout the season.
Keeping things growing
Small root crops like radishes, as well as leafy greens like lettuces, spinach, and kale, mature in 50 to 60 days. Plants like brassicas, onions, carrots, and other root crops can take a month longer.
In order to have a constant supply of the greens, from late fall to mid-winter (roughly December to February), you can start new seeds indoors every few weeks. Once those new seedlings have two or three sets of leaves, transplant them into the garden. As the older plants age out, harvest them and make more room for the younger plants.
If you’re diligent, over the course of the season, you can get three or four successive plantings ensuring you have plenty of garden-fresh vegetables all through the winter – and even into spring!