Look for cutworms on leaves after dark.

With frosty nights forecast this week and even a chance of snow in some places (!), mulching the garden is top of mind. The problem in my area is that many trees still have most of their leaves due to the long warm fall. I find myself standing under my biggest maple, exhorting it to get on with it! The soil is still warm enough now that there is no risk of frost damage to roots in the soil, but if you have mulch to spread this week, the priority should be roots crops that have “shoulders” sticking above the ground. Beets, in particular, push up out of the soil, especially the long Cylindra types, so they are at the top of my list, along with celeriac, to get the first mulch. Empty beds are another priority for mulch to protect the soil from erosion and prevent compaction in the heavy rains that have been arriving in storm after storm. I expect it will take a week or two yet for all the leaves to drop so just keep raking between storms and mulching as you can. Now that leaves are wet, they stay put in the face of winds. If using new straw as a mulch, lay it down right before it rains to get it wet quickly and keep it from blowing away. Ideally, try for a couple of inches of fluffy mulch (more is better) around all plants and over empty beds. By the end of November/early December (or before there is a really cold spell) pile a deep layer of mulch over the tops of root crop by the end of November. Some people cut off the leaves of carrots, etc. before mulching, but there is no need to do that; just leave the leaves on the plants to help mulch the beds.

Mulch and tarps.

Pest notes: You can safely take the insect netting covers off of carrot beds and other crops now. I was quite surprised to see how many leafminer eggs were still being laid daily throughout October on spinach leaves, which was likely an indicator that root flies were also still laying eggs. Another surprise was finding a couple of enormous climbing cutworms one evening as I was out with a flashlight. Looks like those critters also grew quickly in October because they are usually much smaller at this time of year. This week it would be well worth spending a few minutes just after dark looking through lettuce and leafy greens for cutworms. If you are not sure what to look for, see. They are such voracious eaters that one can do a lot of damage so even if you only find a couple of cutworms, that may be all there were. Of course, slugs are going to continue to do a certain amount of damage….

Given the unpredictability of weather these days and the fact that we are still in the La Niña climate pattern, it would be a good idea to prepare now for periods of cold [which I define as several degrees below freezing, -3 to -5oC (23-26oF)]. If you have a greenhouse or coldframes for winter crops you are all set. But if you don’t have such structures, temporary covers work just fine. Stockpile light tarps or plastic sheets where they will be handy if needed. At the same time, make a stack of rocks, bricks or boards to hold down the tarps. Cold snaps on the coast are usually accompanied by strong Arctic outflow winds so heavy weights are needed. Since it is too cold for plants to photosynthesize, tarps don’t have to be clear plastic—just use anything you have, as long as it is waterproof. Lay the tarps directly on plants with reasonably strong stems (such as broccoli, cauliflower). For softer plants, such as leafy greens, you can also lay the tarp down on them and anchor it, but putting supports under the covers do prevent plants from being squashed (even flattened plants usually do stand up again after tarps are removed). Such supports could be low hoops, a row of short blunt stakes, a length of stucco wire bent into a low arch. Just keep supports low so covers don’t catch the wind. Last spring I made wire covers to keep birds out of my seed beds (1-inch welded wire boxes, 2x4 feet and 6-8 inches high). These should be perfect to support plastic over lettuce, spinach, etc. this winter.

Another approach for those with greenhouses or tunnels is to dig up garden plants and move them into beds under cover. I always dig about half my Swiss chard plants as well as some lettuce, leafy greens, parsley and other salad greens to fill my greenhouse beds where tomatoes, peppers have finished. These mature plants transplant surprisingly well and recover enough to start growing again whenever there is enough sunlight to warm the greenhouse to growth temperatures.

Late sowing experiment: Something that works some years is sowing lettuce and other greens so late in the fall that they don’t germinate until spring. If all goes well, these pop up much earlier that you would expect. I will scatter such seeds later this month in a small bed close to the house to beef up the spring lettuce supply. One of the benefits of saving your own seeds is that you have a lot of seed to experiment with! As our weather gets ever less predictable, we will need to be very flexible with planting schedules and keep on trying different timing.

Upcoming presentation open to the public:

Tuesday, November 29, 6:30 pm. I will be giving a talk via Zoom on Resilient Gardens for a Changing Climate. Our regional climate is changing as the global climate changes with extreme weather events reaching record levels last year. What does this mean for our food gardens and landscape plants? Learn how extreme weather affects plants, including trees, how to design resilient food and ornamental gardens and help plants survive extreme weather. Also find out the role gardeners can have in mitigating climate change, including designing landscapes to capture carbon.

Sponsored by the Vancouver Botanical Gardens Association. To register.