- Linda Gilkenson
More Winter Crop to Sow; Weird Heat Effects; Summer Pruning Fruit Trees
You might want to take advantage of the next few days of cooler temperatures to sow hardy lettuce, spinach and other leafy greens (leaf mustard, leaf radish, Chinese cabbage) as well as winter radishes and daikon. August 8 is usually “Spinach Day” at my house, which is when I sow a big patch of spinach for harvesting from fall through next May. That timing works because the daylengths are rapidly getting shorter so seedlings rarely bolt (long days are what make spinach go to seed). I might wait for another week to sow this year, however, since the long range forecast shows another heat wave on its way next week (when does is stop being called a “heat wave” and become a “heat ocean”?). As I have mentioned many times, getting seeds started under hot, dry conditions means covering the seedbeds with some sort of shading material until the seeds germinate. Just to clarify, as some people have been confused on this point: you can use opaque materials, such as burlap or white plastic, to cover seedbeds only until the seedlings germinate. At the very first sign of the tiniest green tip out of the soil, the tiny plants must have sunlight. Of course in the direct hot sun seedlings will quickly fry and die, which is where shade covers that reduce, but don’t block out, sunshine come in (e.g., 50% shade cloth, wood lath covers or upside down latticework seedling flats).
Other tasks for this week: Final thinning of carrots, beets and other vegetables seeded in July should be done now, as well as removing any plants that are finished, are surplus or are not being used in the rest of the garden. This can free up space to sow the fall crops mentioned above or reduce the area of garden that requires watering. There are only 6-7 weeks left in the main growing season (perhaps a few more weeks than that for hardy greens), so make sure everything has enough space and the best growing conditions for what is left of the season. If plants are slowing down, and especially if they show lighter green new leaves, give them a boost of soluble nutrients with liquid fertilizer, such as fish fertilizer or homemade compost tea (soak some compost 1-2 days in a bucket of water and use the liquid to water the veggies). If smaller plants are being shaded by taller crops, intervene by pruning or staking up the tall plants to ensure the smaller plants are getting enough sun.
Later this month: Any time this month, sow frost hardy lettuce, such as ‘Winter Density’, ‘Rouge d’ Hiver’, ‘Arctic King’, ‘Continuity’ (AKA ‘Merveille des Quatre Saisons’) and others, also arugula and corn salad. Once again I am going to sow a big patch of ‘Winter Density’ on August 30th to overwinter for early lettuce next spring. It is too late to start kale or Swiss chard from seed now, but you might be able to still find starts at garden nurseries. For more details on August plantings, see my Aug. 8, 2020 message: http://www.lindagilkeson.ca/gardening_tips.html Hot weather woes and weirdness: Carrots growing slowly and not as sweet as they should be, has been a common complaint this summer (also poorly flavoured tomatoes). In hot weather, especially when nights are warm, plants use up the sugars they make through photosynthesis every day and don’t have surplus to store in roots and fruits. In cooler weather, plants make more sugars than they need for day- to-day processes so have surplus to store, making flavours sweeter and carrots bigger. Other cellularprocesses that contribute to flavour are also disabled by high temperatures. So don’t give up on your summer carrots: they should get tastier as fall arrives. IF you have not been impressed with the flavour of your tomatoes these days, try picking them when the fruit has turned from medium green to light greenish-yellow and ripen them on the kitchen counter
where it is cooler than the greenhouse or garden. Believe it or not, they will taste better! Once tomatoes have reached the light greenish-yellow stage, the plant no longer contributes to the fruit ripening process. This doesn’t mean your garden tomatoes will end up like the tasteless tomatoes seen in supermarkets in the winter: those are from varieties grown for long-distance shipping. Those have a genetic mutation that prevents the fruit from ripening normally so they can never achieve the flavour and ripeness of garden tomatoes.
And finally, if you see some strange goings on in your squash patch, with strange flowers, the heat is to blame. Flowers that develop with a mix of female and male parts and flowers on the end of a fruit that stay small and never open, are caused by high temperatures when the tiny flower bud was beginning to form. In response to heat and/or drought stress corn ears can also become strangely distorted, with what look like tassels coming out of the tips of ears (the tassels are the male flower and should be growing at the tips of the plants). Summer pruning of fruit trees: This week is usually a good time to prune fruit trees to keep them compact and slow overly vigorous trees. Trees that shoot out long branches each season should not be pruned in the winter because that stimulates growth, whereas summer pruning helps to slow the growth of such trees. 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). Summer pruning of apples and pears also causes some leaf buds to convert to flower buds, which increases the amount of fruit on the branches. Prune back branches by one-half to two-thirds, plus remove watersprouts and obviously crossing branches, if they don’t have fruit right now. You can touch up the pruning job later on when trees are dormant and it easier to see the branches.
New! I have added a presentation (pdf) on how to save seeds to the Presentations page on my website: http://www.lindagilkeson.ca/presentations.html