From Linda Gilkeson:
Now that we are well into September, with rapidly shortening days and cooler nights, there are a few things to do now:
Pinch Brussels sprouts: Right now is good timing to cut or pinch out the tips of the Brussels sprouts plants to force the formation of sprouts lower down, along the stem. If your plants already have nice big sprouts this isn’t necessary, but it is essential if your plants currently have only pea-sized nubs where the sprouts should be. With tip growth stopped, the plants quickly start plumping up their sprouts. Even if your plants are still small because they were planted too late, this is worth trying because it might force a few sprouts to form. As regular readers know, if you don’t have good-sized sprouts on the plant by the end of October, they likely won’t form at all because in the spring these biennial plants bypass making sprouts and go straight to flowering.
Check thinning: This applies to any crops sown for winter harvest, but especially to carrots and beets. Leafy greens and lettuce should also be checked for overcrowding. If your summer sown carrots are not baby-carrots sized by now, they may need to be thinned some more or have a few doses of liquid fertilizer this month to promote growth. Use commercial fish fertilizer or make nutrient rich ‘tea’ by soaking a shovel of good compost in a bucket of water for a day. There isn’t much growing season left! Although last fall was abnormally warm through October, we can’t count on that happening again to help out late plantings. Make sure your fall plantings are well-spaced, watered and, if necessary, have supplemental liquid fertilizer.
Last seed sowing: If you have a cold frame, tunnel or greenhouse, you can still sow leafy greens, such as hardy lettuce, spinach, Chinese cabbage, leaf mustard, possibly radishes under covers. You can still plant seedlings outdoors, but it is too late to sow these directly outdoors for fall harvests. You can sow corn salad seed outdoors now: try sprinkling seeds under tomatoes, peppers, beans and other crops that will be finished in October.
One of my favorite planting schemes is to sow frost hardy varieties of lettuce (e.g., Winter Density, Rouge d’hiver, Arctic King, Continuity, Merveille des quatre saisons) at the end of September for spring harvests. The tiny plants grow a little bit in the fall, survive winter and produce a surprisingly early lettuce crop from March onward. It can also work to sow lettuce, spinach, dill, cilantro (and maybe other crops—let me know what works!) in November, late enough so that the seeds don’t germinate before winter, but come up very early in the spring. November is also good time to scatter seeds of perennial flowers, both cultivated and native species, to provide pollen and nectar for beneficial insects next summer. In order to germinate, seeds of many flowers require stratification, which is exposure to wet, cold conditions (winter, in other words).
Stake up loaded branches: With late season apples, pears and even plums still hanging heavy on trees and the possibility of fall wind storms any time, install temporary supports for branches that might break.
Avoid splitting: If there is a heavy rain this month, late tree fruit and maturing vegetable crops that have been short on water can take up water too fast, which causes them to split. There isn’t a heavy rainfall in the immediate forecast, but keep an eye on the weather in case a September storm dumps a lot of rain. In advance of a heavy rain forecast, if you have the capacity to provide some extra irrigation of fruit trees, root vegetables and cabbages for few days before the storm, it will increase the rate of water uptake in plants and decrease the stress on cells. This late in the season, you may also be able to harvest fruit before a storm hits. Most at risk are tomatoes, soft tree fruit, such as late plums, but even apples will split if conditions are right. Among the vegetables, carrots, potatoes and other roots are prone to splitting, also cabbages, melons and squash that are close to maturity. If fruit or cabbages do split, they should be harvested and used immediately as they will rot quickly. Split root carrots usually keep on growing (despite being deformed) and can be harvested later and salvaged for cooking.
Upcoming Zoom presentation open to all: September 19, 7:00-8:30 Do You REALLY Know What the Problem Is? Without a correct diagnosis first, there is no way to successfully treat a problem. Damage caused by poor growing conditions and extreme weather are increasingly common (there was a lot of that this summer!) and are often mistaken for pests or diseases. This online workshop provides tips on diagnosing crop problems, including how to tell whether damage to fruit and vegetables is caused by pathogens, insects, mites, physical injury or growth disorders. This is a fundraiser for the Salt Spring Island Farmland Trust and is part of their Knowledge Series. To register: https://give-can.keela.co/linda-gilkeson-presents-whats-your-problem
Republished with permission from Linda Gilkeson’s Gardening Tips. See Linda’s website to sign up for her newsletter, purchase books, access free presentations and identify pests and diseases which may affect West Coast gardens.