As the leaves are beginning to accumulate on the ground, it is time to shift into mulch mode. You can’t get a better material than whole leaves for winter mulching! This fall you can also stockpile dry leaves now for mulch next summer—just keep them dry until you want to use them. Where fall leaves are unavailable, use any materials that won’t get too compacted over the winter, such as straw, cut bracken ferns, asparagus fronds or other coarse garden waste. This month, concentrate on layering mulch on empty garden beds and spreading it between overwintering plants. Plan on adding more mulch later when the first really cold weather is forecast, which usually happens in late November/early December. That’s when I pile on a thicker layer of mulch right over the tops of carrots, beets, celeriac and other root crops, essentially insulating them into a living root cellar. To keep the leaves from blowing off this mound of mulch, lay a few boards or a piece of stucco wire or chicken wire on top of the leaves to hold them in place. In mid-winter it is too dark and cold for photosynthesis so the plants don’t need their leaves exposed to daylight and the shoulders of the roots do need to be well insulated from frost. I find it isn’t a good idea to pile on thick mulches earlier in the fall because it can attract rats and mice to burrow into it.
Plant garlic: Any time this month plant garlic cloves for next summer’s harvest. It is essential to plant garlic where no plants in the onion family (garlic, onions, leeks, shallots) have been grown for at least 4 years. Crop rotation is the only effective way to manage plant diseases that survive as dormant spores in the soil, including the many kinds of root rot diseases that plague garlic. By removing susceptible host plants for 4 years, spores in the soil die out before susceptible plants are grown there again. An exception is the disease called White Rot, which can remain as dormant spores in the soils for many years; while White Rot can occur in gardens, other root diseases of garlic are more common and they are preventable with 4-year crop rotations. Check your garlic carefully for signs of disease or deterioration before planting. Don’t even plant healthy looking cloves if they came from a bulb that has any other cloves that look diseased. If your garlic crop is healthy, it is safer to keep planting from your own stock every year than it is to risk importing White Rot by bringing in new bulbs from elsewhere. This is the wrong time of year to spread manure or soluble fertilizers (soluble nutrients, especially nitrogen, leach away in the winter rains), but you can enrich your garlic soil with finished compost if needed. Or plant the garlic after peas or beans which will have left nitrogen in the soil for the next crop. If your soil is acidic (low pH), mix in agricultural lime before planting the garlic. Apply a thick mulch to the garlic bed for winter and don’t worry if the tips of garlic shoots start showing in mid-winter: they are very hardy and won’t be harmed by winter cold.
Greenhouse tasks: I was asked about growing vegetables in an unheated greenhouse over the winter and indeed, many crops do very well in greenhouses, high tunnels or coldframes. The extra protection from heavy rain, high winds and frost means that a variety of hardy greens and cabbage family crops do especially well; growth will be quite slow, but they will still grow more than they would out in the garden. It is too late to start from seed now, but if you have space to fill, you can dig up lettuce, Swiss chard, spinach, parsley, Chinese cabbage and other hardy greens from the garden and move them into greenhouse beds or planters. As my greenhouse tomatoes, peppers, etc. finish, I replace them with plants dug from the garden until by November there has been a complete change-over to winter crops.
Get a soil test: Now is a great time to get a pH test for your soil to find out whether or not you need to add lime to the soil. The testing labs are less busy and this is also the best time to apply lime to the garden, though it can be applied any time of year. Send or take your soil sample to an soil testing laboratory and don’t rely on kits or pH testers you can buy at garden centres, which are not at all accurate. Brief instructions for soil sampling are on the MB Labs website and available from extension departments on Oregon and Washington State University web sites.
Oh rats! Rat populations do seem to be on the increase around the region and some gardeners lost squash, tomatoes, beets, carrots, apples, figs, grapes and other fruit to rodents this summer. Rat numbers can be extremely high in neighbourhoods with a lot of food on offer from gardens, bird feeders, chicken houses, uncovered compost bins and other sources. As some gardeners found out this summer, it is hard to attract rats to traps while there are plenty of tasty garden crops available. Now, with fruit and squash harvests finished, is a good time to get a rat control program in place. This includes removing bird feeders that spill seeds and using only rat-proof bins for composting kitchen waste. With the ban on toxic rat baits for the next 2 years in BC, all that is currently available to home gardeners are traps of various designs (the ‘safe’ cellulose baits still being sold are not very effective as rats have to eat a lot of bait before they become ill enough to die—and rats avoid food that makes them feel sick). I have never liked using snap traps because birds can also get caught in them, however, I now have the small, very strong rat traps [TomCat brand] that fit inside the black ‘clamshell’ type of locking bait boxes. With the trap inside the closed box, birds and pets can’t get caught, although racoons will still try to figure out how to reach whatever you are using to bait the trap (use a length of wire to anchor the box to something to prevent racoons from hauling the box away). There are various models of electrocution traps and a variety of other trap designs that seem to have some successes and some failures. If rats are doing a lot of damage it might be advisable to hire a professional pest management company to place effective traps in the best locations for catching rats.
Band trees for Winter Moth: If you saw a lot of small green caterpillars feeding in apple, oak and other deciduous trees last spring, it was probably caterpillars of Winter Moth. Mid-October is the time to install sticky bands on the trunks of trees to trap the female moths as they walk up the tree trunks on their way to laying eggs out on tree branches. Such traps works because the female moths only have stubs of wings and can’t fly. For details on what to use for bands and how to install them, see my October 8, 2019 message.
Carrot covers can be removed soon: If you have insect netting on your winter carrot bed to prevent carrot rust fly attack, you can remove it after frost (which some places in the region have already had) or certainly by the end of this month. Some years we have warmer weather in October, making late insect attack more of a possibility than it would be this year with all the cold, wet weather we have had.