Natural gardening: companion plants and manure

Gardening enthusiasts frequently call me with questions or comments. And, although I can help with some issues, I always recommend that they consider calling specialists we’re fortunate to have living among us right here in the Pontiac.

For example, Louise Ardern of Blue Heron Landscaping, north of Shawville, is very knowledgeable about gardening (647-5094). She and family have a thriving horticultural business and welcome questions, as do the owners of Belle Terre Botanic Garden and Arboretum, near Otter Lake (453-7270).

Here is both a question and a comment that I recently received from readers, which I thought might be of interest to those of you whose goal it is to create a natural, pest-free garden.

1. Companion plants for roses

Neighbour Amber Walpole called to inquire what she should plant near to her Explorer roses (species specifically bred to suit our Canadian climatic extremes) in order to repel pests.

First of all, what is companion planting?

It is a method of planting types of plants in close proximity, so that they “help” one another to resist bugs or blights, or infuse the soil with helpful nutrients. Optimally, both plants will benefit. However, the term is also used to recognize plants that should not be planted near one another (as with beans and onions).

In response to the question of what to plant alongside roses, I recommended marigolds. However, after her own research, Amber instead decided to plant members of the onion family next to the roses.

In fact, both companion plants are recommended in the well-known reference book, Carrots Love Tomatoes: Secrets of Companion Planting for Successful Gardening.

Using roses as our example, here’s what author Louise Riotte tells us.

“All the alliums - garlic, onions, chives and shallots - are beneficial to roses, protecting them against black spot, mildew and aphids. … Garlic and onions are particularly beneficial.”

But there are other plants, too, which help roses.

“Roses also are aided by the presence of parsley against rose beetles, onions to repel rose chafers, by mignonette as a ground cover and lupines to increase soil nitrogen and attract earthworms. Marigolds are helpful against nematodes, and geraniums or milky spore disease against Japanese beetle. A carpet of low-growing weeds from the purslane family among rosebushes will improve the spongy soil around their roots. An infusion of elderberry leaves in lukewarm water sprinkled over roses is thought to control caterpillar damage and is also recommended for blight.”

Because it is such a hardy, successful species, the Rosa rugosa has a special section all to itself in this book. This extremely prickly rose is the one you can see that throngs the banks of the Rideau Canal in Ottawa: it forms a profuse, dense bush such that it is often planted as a hedge. Flowers can be deep pink or white, after which extremely chubby hips are formed. These are a superb source of vitamin C, incidentally, and so rosa rugosa is grown for the soup, tea, jams, and jellies that can be made from their scarlet coloured hips (seed pods).

Other fascinating companions:

Catnip, the mint that cats enjoy so much, contains a natural insect repellent called nepetalactone: Ms Riotte recommends seeping catnip in water, then sprinkling it on plants. She claims this is particularly efficacious against flea beetles.

2. Horse vs. cow manure

Which is better for your garden, well-composted horse or cow manure?

Equity reader Neil Dunlop took the trouble to contact me, saying he’d read a recent column wherein I’d recommended you try horse manure on your garden.

Don’t do it, says Neil! On Monday June 18 he called to advise me. “What kind of soil do you have?” he first asked. When I told him I have sandy soil, he told me to avoid using the horse manure, because it is too hot and dry. “Use cow manure,” he commented. “Of course, the best thing to use is compost.”

Personally, I haven’t seemed to experience any problems with the horse manure (yet?!) and certainly my neighbour’s gardens are thriving, although because their soil is clay perhaps the hotter, drier horse manure works well with their soil conditions.

Yet again, possibly I’ve not experienced problems because I’ve mixed the horse manure into the compost that my husband Eric and I have created in our open-air compost bins.

Now, what about sheep manure? Among all my readers, there’s got to be someone who advocates sheep manure over either horse or cow. Perhaps this column will flush you out, and I’ll hear from you!

… Actually, Amber Walpole bought sheep manure specifically for her roses, upon the advise of the Galetta nursery where she purchased her roses.

So there you are: manure for all purposes!

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Birdwatch

Neil Dunlop also told me that two woodpecker families are nesting at his Forest Haven campground. For the first time, one family has chosen a cedar nestbox that used to be green, but which was recently repainted red. He wonders if the colour change has any bearing on the box finally being selected as a good nest site.

Russ Taber of Quyon reports observing 8 Canada Geese with 30 goslings (young geese) in tow.

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Katharine Fletcher is a freelance writer and keen gardener based north of Quyon. Contact her with your questions, comments, and opinions at fletcher.katharine@gmail.com or 458-2090.