Aristotle, the ancient Greek philosopher, is credited with originating the adage “Nature abhors a vacuum”. To be clear, we are not referring to a Hoover or a Dyson; rather, it is a way of saying that there is no such thing as a completely empty space. Does this matter to gardeners? Yep, bare soil will inevitably fill up with dandelions or any number of unwelcome invasive plants.
So, do you still have bare soil in your garden? Don’t despair if you haven’t planted all your vegetable garden yet. June is not at all too late to plant many vegetables. Seeds of relatively short-season vegetables such as beans and zucchini can be planted now with a reasonable expectation of success. Vegetable seedlings such as tomatoes, peppers, cucumbers or brassicas may still be planted as well — in all likelihood seasonal garden centres at box stores will have these plants on deep discount as they wrap up their operations for the season.
Even if you already have your garden fully planted, there are still opportunities for additional crops. While it seems like we are still a long way away from a meal of fresh beans from the garden, nonetheless it is time to think about planting another bed with beans and beets and maybe carrots (perhaps where the lettuce and spinach have gone to seed and been pulled out).
Many gardeners subscribe to succession planting. Rather than plant all the beans at once, plant every two or three weeks — thus spreading out the harvest over an extended period. This can continue over the summer. The average bush bean takes about 50 days from seeding until harvest (beets take 55 to 60 days). Given that the weather will likely start to cool off considerably by mid-September, I will want to plant my last crop of beans about mid-July. This also creates the opportunity to have more than one harvest from the same plot of land — I will be placing my later plantings of beans and beets in areas where I have harvested lettuce, spinach, peas, and early onions and potatoes.
And like a lot of suggestions, this may turn out much better in theory than in reality. Invariably we have a period of very dry or very cool weather following our first planting and the seeds end up germinating the same time as the second planting. The best laid plans…
Mid-August will also be an opportunity to plant vegetables such as spinach, lettuce and other greens that will grow very well as the days get shorter and cooler in the fall. The trick is to get them to germinate in warm soil. Frequent watering may be necessary.
And don’t forget the opportunity to plant a cover crop or green crop when a bit of real estate opens up in the garden, perhaps after the garlic is pulled or the early potatoes are dug. While very similar, the purpose may differ. Green manure involves growing specific plants to be plowed back into the soil to enhance nutrient content and organic matter, while cover crops are planted primarily to protect soil from erosion, suppress weeds, and improve soil structure. Both practices improve soil health, but green manure focuses more on nutrient enrichment, especially nitrogen fixation, whereas cover crops emphasize preventing soil degradation and maintaining moisture. Green manure is one of the best ways to increase soil tilth and add organic matter during the growing season in areas not in use or being summer fallowed, whereas cover crops are planted primarily in the fall as an over-wintering crop (to hold the soil and organic matter in place for the spring). Using legumes as a green crop allows nitrogen to be fixed from the air into the soil for use by a later crop.
I often plant buckwheat in mid-summer as a way of smothering weeds. It loves hot weather, germinates and grows quickly, and has beautiful flowers loved by pollinators. It is very frost-sensitive, so is not well suited as a fall cover crop. I cut it down and work it into the soil before it produces ripe seeds.
My go-to cover crop in cooler seasons is common, garden-variety oats. They love cooler weather, and when planted in late summer grow until late fall. They will be winter-killed but will stay in place, preventing soil erosion all winter, and then can be worked into the soil in spring. When planted in spring they need to be cut down before seed is formed.
I have had mixed results with tillage radishes, which are grown to break up heavy clay soil. They did not completely winter-kill as promised, and one can only eat so many daikon (tillage) radishes. Rye also refused to die over the winter and took a fair amount of effort to eliminate in the spring.