Living Columns & Blogs

Ask a Gardener: Get ready for winter with plantings, cover crops

Brussels sprouts are one of several plants that you can plant for winter harvest.
Brussels sprouts are one of several plants that you can plant for winter harvest. Tribune News Service

Question: I’ve heard that cover crops are great for gardens. Is it true? What would you recommend?

Answer: Though it’s hard to believe that fall and winter are nearing, with luck it will happen, and bring our plants much needed rain. Of course predicting when is dicey, but now’s the time to think about putting in a cover crop for the winter.

Cover cropping is putting in an overwintered green crop, and it has several advantages. First, it is a soil improver that is produced on-site, and is therefore less likely to cause any problems with your soil’s nutrient balance. Second, a thick vegetative covering produces soil in much better condition for spring planting. Third, cover crops greatly help in controlling erosion from heavy winter rains.

And for those of us who are ever-anxious to start gardening at the earliest time in the spring, and are perpetually frustrated when the ground never seems to dry out enough to work, cover crops are the answer. The green plants form a dense leaf cover that stops the rain from beating directly on the garden. Result? The soil will be much drier and softer in the spring.

Choices are many when choosing which cover crop to plant. Avoid like the plague red clover. I made the mistake of once planting it, and, though pretty, it took ages to get rid of. Vetch is another one to avoid, as the seeds can languish in the winter soil, emerging later in the spring as a hard-to-eliminate weed.

Best choices for the Northwest are crimson clover and small-seeded fava beans. You can get the seed in nurseries, farmer’s stores and online.

Here’s a quandary, however. This time of year, when you need to plant your cover crop, you still have plants growing in the beds. There’s an easy solution, however. If you interplant the seeds around the existing plants, by the time the cover crop plants need to stretch out, you will have harvested whatever was there to begin with.

Come spring you will cut the cover crop down (a lawnmower or weedwacker work well) and then turn the plant debris into the soil. You don’t even have to wait until all the cover crop has dissolved to plant. Consider the debris to be a bonus fertilizer for your new plants. If you can’t tolerate a temporarily messy bed, put the cuttings into your compost pile where they will decompose quickly.

If you’re going to plant a cover crop, the time is between now and mid-August. It will need time to sprout and get some size before it’s too cold and wet.

Q: I don’t know about anyone else, but I am having a terrible time with something that’s ruining my beets, chard and spinach leaves. What could it be, and what can I do to stop it?

A: What you’re no doubt looking at is the damage that’s done by a small fly similar to the cabbage fly or carrot rust fly. The larvae tunnel through the leaves, leaving them ruined. No surprise it’s called a leaf miner.

Not much in the way of insecticide, synthetic or organic, will control the leaf miners, as they are within the leaves, and thus protected. However, floating row covers, put on just after the seedlings are large enough to thin and weed, and kept on until harvest, will do a good job of keeping them at bay. Be sure to completely secure the row cover. I’ve found that long boards do the best, read easiest, job.

Q: Though it’s great to grow vegetables in the summer, it’s in the winter when I really would like to have my garden producing. I know it’s possible, but how do I get started?

A: I find nothing so satisfying than harvesting greens for dinner in the winter. Now is the time to plan and act if you want to extend the season. In fact, you might be a little late for some plants, but there are many that you can still plant.

Here is a partial list of plants that can extend into the winter, or that you can plant for winter harvest: Brussels sprouts, carrots, collards, kale, chard, kohlrabi, leeks, onions and spinach.

Choose vegetables suitable for fall/winter gardening. Make sure where you plant them is well-drained, and choose the warmest location you have. Fertilize when planting, but not after the rains start. You may choose to use floating row covers, cloches, etc. to protect from hard freezes. Though there are fewer insect problems in winter, the rabbits, deer, slugs, and voles are still active, and you need to watch out for them.

My go-to resource is “Winter Gardening in the Maritime Northwest” by Binda Colebrook. Good information is also available from Washington State University Extension:

Have fun, but start small. There’s always next year to expand your knowledge and your winter garden.

Gardener note: As you prune any trees or bushes, keep some of the branches to use as plant supports in your garden or pots. They are much more inconspicuous than something made of plastic or wood, and there is always an unending supply of them.

Kathleen Bander of Bellingham is a life-long gardener. Her column will appear in The Bellingham Herald weekly through the summer growing season. If you have a gardening question you'd like answered in the column, please email it to For more gardening information online, go to