Garden Clippings for Feb 4, 2023

Josiah on Brock Street has a lovely heritage home.  It was built more than a century ago, by someone in the railroad business.  The front of the house, with its big welcoming porch was perfect for meeting and greeting neighbours, but is now rarely used because we now travel by car rather than by foot.

For being near the core, Josiah’s backyard is huge: an oasis with formal patios, a stately gazebo, a dilapidated greenhouse that was once used by the gardener, several trees and a collection of flowering shrubs along the border, providing ample privacy.  There is a concrete pool along the west fence, the only spot with sun.

“I’ve often thought of getting rid of the pool”, says Josiah.  “Not because we rarely use it, but because the neighbours’ Locust trees are such a nuisance.”

The issue with Locust trees and swimming pools is their leaflets are so small that they constantly plug up the skimmer.  The leaflets are also difficult to clean up with a net at the end of a pole.

More than once, Josiah asked his neighbours if they would cut down the trees, even at his own expense, but the neighbours won’t entertain the idea.  They love their Locust trees, because leaflets are small and never need to be raked up.

Leaves of Locust are about 5 inches long, and compound, meaning each leaf is made up of a thin central stem, with tiny leaflets on both sides.  Locust is a fine-textured tree, casting filtered shade on the ground below.

Ontario’s original Locust, commonly known as Honeylocust (Gleditsia triacanthos) is a native tree with many thorns.  It is so named because centuries ago, folks ground up the seeds into a sweet tasting concoction.

A few decades ago, in the nursery business, updated Locust cultivars, without seeds and thorns, were almost as popular as Norway Maples.  They were a savior in every city’s downtown because they grew anywhere, no matter how tight the spot or poor the soil.  The three most widely planted Locust varieties were the broad-growing Shademaster Locust, the tall-growing Skyline Locust and the golden-leafed Sunburst Locust.

Locust are members of the pea family, and like other members of the bean and pea family, Locust has a built-in ability to fix nitrogen out of the air, into a form it can use.  This ability to feed itself bodes well for the Locust, enabling the tree to grow in the poorest of soils.

Black Locust (Robinia pseudoacacia) was introduced to Canada by our neighbours to the South, where it is considered a native tree.  It now grows freely in Southern Ontario, east to the Maritimes and in the West Coast.  In Southwestern Ontario, it can be found in nutrient-poor sandy soils including parklands, along roadways, abandoned fields and at the edge of forests.

Flowers of Black Locust are edible, and very tasty.  Pull a string of white pearls off the tree, put the whole string in your mouth, and pull the stem out, leaving the flowers in your mouth.  And while the flowers will have you coming back for seconds, the roots, stems, and leaves of Black Locust are poisonous.

Here in Sarnia, we have clusters of Black Locust growing along the Howard Watson Nature Trail.  Black Locust is horribly thorny, and can be aggressive in growth, often drowning out timid wildflowers.  The tree will not grow in shade, so there is little fear of Black Locust entering our forests.

Black Locust produces seed pods, but its seeds rarely sprout.  Instead, it propagates and spreads by sending new shoots or suckers from its roots, making the tree difficult to eradicate.