Busting Horticultural Myths – Prince Albert Daily Herald


Often we are presented with advice that sounds like fact. “Bone meal is good for plants” or “Native plants are always the best choice”. You might think that experience has taught us that there are few facts in life, but things are not always so clear cut, especially in the world of horticulture.

A Washington State University-based website tries to break down a lot of popular notions we have about how to be successful gardeners.

Here are some of the most common “myths” and what they say about them.

Myth of xeriscaping.

We have written about using plants that handle high and low amounts of water. You could say that once a sedum plant is established, it doesn’t need any water from us. According to the website’s article on the subject, “Xerophytes (plants commonly used in the xeroscape) are particularly adept at absorbing and storing water when it is available.”

Plants that don’t require a lot of water often go dormant when dry, dropping leaves and flowers. Ironically, a study in Arizona found that homeowners understood the ecological benefits of xeriscaping, but often ended up irrigating more to maintain aesthetics throughout the dry season.

Lesson? Resist the temptation to water a xeriscape garden in times of drought, no matter what it looks like when dry. The important thing with xerophytic plants is that they will come back when the drought subsides. Just be patient.

Myth of the superiority of native plants.

We champion native plants and gardens. Mark is president of Trees For Life, a non-profit organization dedicated to planting native trees in urban settings. But there’s a caveat, according to the University of Washington’s website, native plants can suffer “significant compaction and other physical disturbance from animal, foot, and vehicular traffic.” . Alkaline pH due to leaching of lime from the concrete. Lack of mulch or other soil protection, lack of adequate water during summer months, increased heat load due to asphalt reflectance and air pollution. We find it hard to say that the urban environment can be very hostile to plants, native or not.

The key is to choose plants that are suitable for their growing conditions. Sun and shade are easy to determine, but also consider soil (clay requires careful plant selection), compaction from human traffic, and only plant forest plants in a forest.

Myth of landscape fabric: its use provides permanent weed control.

Our experience tells us that the reverse is true. We don’t need this website to tell us that once geotextile (synthetic) landscape fabric is laid, it harbors weed seeds, becomes entangled with the roots of existing plants and begins to degrade but does not never completely disappears. Weed control claims are indeed a myth. Mark recently purchased a home where the previous owner used large amounts of landscape fabric for some purpose. He tries to imagine what went through the owner’s mind, as Mark pulls things out by handfuls.

Bottom line: there’s no substitute for regular weeding and mulching with a natural material like cedar bark.

You can have fun enjoying the contrarian sights at “https://puyallup.wsu.edu/lcs/” https://puyallup.wsu.edu/lcs/, or consider joining Garden Myth-Buster’s own Robert Pavlis from Canada at his website “http://www.gardenmyths.com” www.gardenmyths.com and his very active Facebook group of the same name.

You don’t have to feel like you have to agree with the views offered here, but they will lift your spirits on a cold winter’s day.

Mark Cullen is an expert gardener, author, broadcaster, tree advocate and Member of the Order of Canada. His son Ben is a fourth generation urban gardener and a graduate of the University of Guelph and Dalhousie University in Halifax. Follow them at markcullen.com, @markcullengardening and on Facebook.


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