There is still time to sow hardy winter lettuce and arugula if you do it this week and now is also the perfect time to sow corn salad for winter salads. Pull back mulches and scatter seeds under tomatoes, squash and other plants that will be finished in October. Corn salad seeds may not germinate until the soil cools down, so don’t worry if they don’t come up immediately; it is extremely hardy and one of the few greens that can grow (slowly) during the winter. If you are sowing winter greens in a coldframe, plastic tunnel or unheated greenhouse, you could also sow Chinese cabbage, leaf mustard and other hardy greens now, because the warmer environments provide a little more growing time. If you can buy starts of spinach, lettuce, Chinese cabbage and other leafy greens you can still transplant those into your garden (on Salt Spring, Chorus Frog Farm stand still has these available). Grow them as quickly as possible in nitrogen-rich soil with plenty of water. Even if plants don’t get large enough to for harvesting this fall, they will still be the first to produce a crop early in the spring so don’t give up on them. Forecast temperatures from now through next week look to be ideal for germination and growth of lettuce and cabbage family greens, but if we get hot days later on, don’t forget to shade the seedlings.
Thinning reminder: Do check winter root crops this week, weeding and thinning plants if necessary to give them a chance to put on weight in this last month of good growing conditions. Don’t worry about removing insect netting or floating row cover during the day while working on carrots: carrot rust flies lay eggs at dusk, so as long as you cover the beds as soon as you are done working, it is very unlikely that one will get in. But do replace the covers because the adult flies will be around laying eggs all fall. You can safely remove covers at the end of October and put them away.
Splitter alert: When periods of rain start again after this extremely dry summer, watch out for splitting fruit and vegetables. When plants take up water faster than the root or fruit tissue can grow, they often split. Split carrots and other roots remain edible, though ugly, and you don’t have to dig them early, but split fruit has to be picked because the exposed pulp decays and attracts wasps, bees and other insects. Cabbages can also split so if that happens, use the cabbage immediately as the head will rot. When the first heavy rain occurs, prevent cabbages from splitting by cutting or disrupting some of the roots to slow the uptake of water. Give each head a gentle yank or a slight twist in one direction to break some roots (but not enough to dislodge the plant) or use a shovel to slice down on two opposite sides of the cabbage to cut some roots.
Miscellaneous notes on pests and problems this time of year:
Those very small golden brown butterflies that have been so common this month are our native Woodland Skippers (there may also be other similar skipper species present, depending where you are). And yes, as several people have pointed out, they do look like moths with their fat little bodies and stubby wings, but they are actually butterflies. Rest assured they are not pests and are not doing anything to your plants. In fact, I found it a welcome surprise to see skippers appearing this year in high numbers—like they used to some years ago.
Web spinning caterpillars: The nests of webbing that you see on here and there on trees right now are not tent caterpillars making a comeback—they are a different species called Fall Webworm. They don’t go on to reach high outbreak numbers like tent caterpillars do in some years. Tent caterpillars hatch from eggs in April and chew on leaves May to early June. While their numbers are starting to rise over the region, with very high numbers occurring locally in the Delta, BC area this year, it will probably be a year or two (or three) before other areas in the region see outbreak numbers again.
Sting-y thingies: If you have been concerned about the number of wasps and hornets of all sizes around this summer, you might be relieved to know that their numbers will diminish over September and all but the queens will die before winter. They don’t re-use their nests so if you are worried about a nest now, it won’t be much longer before it is vacated. Meanwhile, I hope you can appreciate how many caterpillars have disappeared from your garden, snatched by wasps to feed their larvae back in the nest. In one study, 225 caterpillars an hour were counted being ferried into one nest by worker wasps.
Blossom end rot in tomatoes was really common this year. This appears as a black or brown area on the bottom or blossom end of the fruit. The damage ranges from small tar-like spots to blackened areas covering the bottom half of the fruit. This is not a disease: it is a calcium deficiency in the tissue of the fruit. This can be because of lack of available calcium in the soil, but is usually not due to a soil deficiency, but by irregular watering. When soil dries out the plant can’t get calcium from the soil since the mineral moves into the plant along with water. In dry soil, the plant experiences a calcium deficiency until soil moisture is restored. There can also be a temporary calcium deficiency in fruit when the fruit is growing too fast (from excess nitrogen fertilizer); the calcium transport inside the plant can’t keep up with the needs of the cells in the expanding fruit. Which is why blossom end rot tends to be worst on large fruited tomatoes and paste tomatoes. Note that trying to solve this by adding Epsom salts (magnesium) makes the problem worse by causing a further imbalance of calcium. Keeping on top of watering so that the soil, especially in pots, is kept evenly moist solves most blossom end rot. Keeping a thick mulch on the soil surface helps even out soil moisture.
Rats, racoons, squirrels: This time of year the nibbling and marauding creatures take a toll on ripening crops. For descriptions of what kind of damage each critter does and how to avoid it, see my Sept. 1, 2017 newsletter.