This month we are coming to the end of the seeding season for winter harvest vegetables. With the cooler temperatures this week, conditions are ideal for sowing lettuce, spinach and other leafy greens (leaf mustard, leaf radish, Chinese cabbage) as well as winter radishes and daikon. For sowing this month, choose frost hardy lettuce varieties to extend your harvest all winter. There are some excellent hardy lettuce varieties, including ‘Winter Density’, ‘Rouge d’ Hiver’, ‘Arctic King’, ‘Continuity’ (AKA ‘Merveille des Quatre Saisons’). These can be sown up until the end of this month, along with arugula and corn salad, which is a super-hardy lettuce substitute for winter months. The leaves are small (so grow lots), but the plant is indestructible in winter ice, snow and below freezing weather.
If you haven’t sown kale, collards, leaf beet or Swiss chard before this, try to find seedlings to transplant as it is getting too late to start these larger plants from seed. If you are sowing now, plant immediately (today!) and make sure seedlings grow as quickly as possible: thin them as soon as they come up and provide plenty of water and nutrients (enrich the soil with blood or fish meal, fish compost, alfalfa meal or other amendments higher in nitrogen).
Today is Spinach Day at my house as this is perfect timing to sow spinach for fall, winter and spring harvests: days are short enough now that most spinach seedlings won’t bolt even in hot weather. Spinach does best if it is protected from heavy winter rain by being grown under the overhang of a roof or in a cold frame or tunnel. Mulch the soil around the plants in November to protect the roots. And no matter how battered your plants are by winter weather, don’t give up on them, because most will survive to sprout a whole new crop of leaves in March and April.
Now is also time to check that carrots, beets and other crops sown in July are well weeded and thinned. There is really only 6-7 weeks of good growing season left, so make sure your plants can make the most of the last days of summer by providing the best growing conditions. If you have carrots under insect netting to keep off carrot rust fly, take the netting off in mid-day to thin and weed the crop, then re-cover immediately (adult rust flies come out to lay eggs at dusk). The same goes for insect netting used over radishes and other cabbage family crops to protect them from cabbage root maggot. And just a reminder: insect netting for these pests should remain in place until the end of October.
Summer pruning: This week is also good timing to prune fruit trees to keep them compact and slow down excessively vigorous trees. Trees that shoot out several feet on each branch over the season are growing too fast. Peaches and cherries often grow 4 feet or more each season, but other trees can do this too, especially in a year they carry little or no fruit. Such trees should not be pruned in the winter because that stimulates growth, whereas summer pruning slows growth. Start pruning when the tree is no longer putting on new leaves at the tip of the branches (new leaves are smaller and a lighter green than mature leaves). This is usually around the end of July, though some trees put on new leaves until early August. Summer pruning of apples and pears has another benefit in that it forces some leaf buds to convert to flower buds, which increases fruit production. Cut back branches by half and also remove watersprouts and new shoots that are going in the wrong directions. You can touch up pruning of most trees in the winter, when it is easier to see the branch structure, but avoid winter pruning for really rampant trees.
Year Round Harvest Courses: I expect to offer my gardening courses again in 2021, one at the Horticulture Centre of the Pacific (Victoria) and one on Salt Spring sponsored by the SS Garden Club. The courses are currently running via Zoom and next year’s classes may be a mixture of Zoom and in-classroom, depending on how things go with Covid-19. The courses meet once a month for 10 months starting in January. Dates are not yet established, but if you are interested in the Victoria course, contact HCP directly to get on the notification list. If you are interested in the Salt Spring course, contact me directly: email@example.com