“A garden that is designed only to look pretty barely skims the surface of what landscapes can offer.” –Toby Hemenway, “The Gardener Says”
June is the month when even the smallest, unpretentious garden has something indescribably lovely in it. June weddings, graduation parties — all are enhanced by June gardens setting the scene. With all the floral abundance, it might seem counterintuitive to illustrate this edition of Garden Notes with the humble red clover.
I acquired red clover in my vegetable garden unintentionally. It put itself in the central path of lawn that runs down the middle. At first I used to attempt to weed it out, because it grew faster and taller than the turf I thought was so attractive and desirable. Then I just tried to contain it by mowing. Now, I leave it alone, having finally realized that it is probably one of the best plants I have in there.
When the patches of red clover (Trifolium pratense) present their oval mauve flowerheads and I witness the riot of bumblebees visiting them in sunny hours, I know that it is correct to leave plants that we sometimes have no plan for.
In more institutional terms, red clover is an important fodder plant, and is used as a component of green manure mixes, which is probably how it came into my garden. Originally native to northern Europe, it is now globally distributed. The plant’s roots go deep, as I discovered by attempting to weed it out, and so red clover is an admirable soil-holder and -builder, due to its ability to fix nitrogen in soils.
Medicinal claims are made for red clover, and teas made from flowers have been used since long ago for female complaints. Red clover contains isoflavones that convert to phytoestrogens in the body that are similar to estrogen (webmd.com/vitamins/ai/ingredientmono-308/red-clover).
Bumblebees are the exclusive pollinators of red clover; therefore commercial sources of seed for the valuable fodder and green manure crop depend upon the black and yellow furry pollinators.
In late April or early May, I was sitting outside with a drink after work when I heard a regular faint tapping behind me. I could not see anything, but the tapping noise continued. Expectantly, I continued listening until sure enough, a tiny brown wren came around the trunk of the large white oak behind me, pecking at a lot of “somethings” on it. She looked as if she was cleaning the tree’s trunk, but was clearly harvesting edibles of some sort.
While the human focus is on coronavirus, Island trees face their own health problems, including the effects of caterpillars. Fingers crossed, so far, winter moth and tent caterpillar numbers seem moderate. Caterpillar outbreaks point up once again the importance of our bird populations.
Spring is when insect protein is particularly important for feeding and growth of baby birds; having plenty of bird life to harvest caterpillars can only help in an ecological way very different from spraying. I suspect the wren was picking off minute emergent caterpillars heading up the tree to enter its buds.
Magenta and mauve not your favorite colors? Then I guess you are not equipped with pollinator eyes. Researchers have learned an amazing amount about insect vision, considering the hurdles in getting feedback from a bunch of insects.
In my garden stand two large rhododendrons covered in blossoms, side by side. One is the baby-girl pink Dexter Hybrid “Scintillation,” the other magenta “Roseum Elegans.” Guess which one is abuzz with bumblebees, and which has fewer?
The above is anecdotal, to be sure, and “Scintillation” opened a bit earlier than “Roseum Elegans,” whose flowers were therefore fresher, but nonetheless, for insect interest, plant magenta. Blue, purple, and yellow also seem to be the colors to use to attract pollinating insects.
According to a paper published in the Annals of Botany
(academic.oup.com/aob/article/118/2/249/1741474), the trichromatic vision of honeybees is used as a model for all bees. “Most other insects studied so far also have a trichromatic system, but there are also species with dichromatic (certain flies and coleopterans) and tetrachromatic (mostly butterflies) systems. For example, bee-visited flowers are expected to be blue or violet, and beetle-visited flowers are expected to be white or cream.”
Visit Polly Hill Arboretum
An Island institution not shut down by Covid-19 stands a short trip up State Road in West Tisbury, where everything that blooms now and grows well on Martha’s Vineyard may be seen up close, and examined fully.
June is the time to visit Polly Hill and gather ideas for your own garden and plantings. Plant labeling enables visitors to expand their plant knowledge; well-planned gardens and plant associations show what is possible in Island contexts.
In the garden
Inspect grafted trees and shrubs for sprouts emerging from the rootstock, and remove, preferably by twisting off, not cutting. This includes orchard trees, roses, and shrubs commonly grafted, such as witch hazels and flowering cherries.
The light changes after the summer solstice. Prune spring-flowering shrubs, and those that bloom later on new wood, before then. Perform the Chelsea Chop on perennials, such as phlox and members of the chrysanthemum family.
Roses are in glory. Side-dress bushes with two cups of organic soil food (fertilizer) scratched in lightly, monthly through Labor Day. Likewise, rose sawflies (“rose slugs”) appear, as do aphids. Know your pests. These insects are not lepidopteran, and are better managed with insecticidal soaps, neem, and hort oil applications than with Bacillus thuringiensis.
Strawberries are fruiting. The plants sprout runners that root at the tip and produce new plants. A plentiful crop of large fruit may be produced every year by setting new plants annually and discarding the older ones that lack vigor. Plan for a new bed in a sunny space.