My garden is lush with growth from the rainfall we’ve had in southern Ontario this spring and early summer. Fortunately, there’s also been sunshine to bring out lots of flowers, the result being burgeoning clumps of perennials crowding up against specimen evergreens. Truth be known, I’m from the pack-and-cram school of gardening — I don’t leave much space between plants, because that’s the way I can fit more in. This garden bed overload requires careful monitoring because things can get out of hand quickly in a good growing season. All of which is to say, it’s time for me to start thinning perennials that are too jammed – thick clumps of peonies, columbines, early-blooming daylilies, perennial sweet peas and large hostas.
My immediate concern is that removing stems and foliage could reduce the perennials’ energy-making potential this season and mean fewer flowers next year. But if I’m to maintain order and healthy growing conditions, these plants really need to be slimmed down. For example, I’ll remove up to a third of the stems and foliage from peony and daylily clumps. For the columbines, hostas and perennial sweetpeas, I’ll remove the lowest or outer stems (now leaning down to spread on the ground) to reduce the circumference of each plant. My biggest worry with overcrowded plants in a wet season is the proliferation of fungal spores, particularly because I know many fungi produce winter-hardy spores that reside in soil, and then re-infect plants in future seasons. Removing foliage and increasing air circulation around the plants will make less hospitable circumstances for these opportunistic diseases.
After thinning, I’ll feed the plants to compensate for any energy I may have deprived them of making this season and follow up with a nutritious tonic to boost vigour and ward off seasonal diseases. The fertilizer will be absorbed and stored in the plant crowns for making next year’s flowers, and the tonic will be used immediately to keep plants healthy. There are many recipes for plant tonics, all made from organic ingredients and selective plant species containing essential trace nutrients. I’ll confess that I don’t use steeping methods to make plant teas (such as manure, stinging nettle or alfalfa teas), because I can’t stand the odours these fermented tonics produce. I want a tonic that can be prepared and used within the same day, leaving no sticky or smelly residues.
My current favourite tonic is a mix of molasses and Aspirin. (When I have liquid kelp on the shelf, it also goes into the brew.) I dissolve a crushed Aspirin (325 mg) and three tablespoons (45 mL) of unsulphured blackstrap molasses (available from a health food store and some supermarkets) in one cup (235 mL) of boiling water, and then add that mixture to a gallon (4 L) of water. Sulphured molasses can be used, but its preservatives inhibit the amount of nutrients released. If using sulphured molasses, I would double the dose to six tablespoons (90 mL).
I put the tonic in a watering can fitted with a multi-holed rose on the spout and generously apply a foliar drench, allowing any runoff from the leaves to be absorbed into the soil over the root zone. The molasses contains carbohydrate sugars that feed soil organisms, increasing biological activity in the soil. It also packs a nice meal of iron, potassium, magnesium, sulphur and calcium. The Aspirin is a manufactured form of salicylic acid that triggers plant defenses against bacteria, fungi and virus diseases. I’ll apply this tonic now and again next month. Some gardeners use tonics more often, and rely on them more than fertilizers. It’s worth experimenting to see how tonics make your garden grow.