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Rabbits, Forsythia & Locust Tree

Questions about rabbits, rabbits and more rabbits; Forsythia that do not flower, and what to plant beneath a tree.
by Art Drysdale
by Art Drysdale

email: art@artdrysdale.com

Art Drysdale, a life-long resident of Toronto and a horticulturist well known all across Canada, is now a resident of Parksville, British Columbia on Vancouver Island, just north of Nanaimo. He has reno-vated an old home and has a new garden there. His radio gardening vignettes are heard in south-western Ontario over radio station Easy 101 FM out of Tillsonburg at 2 PM weekdays.

Art also has his own website at http://www.artdrysdale.com


May 1, 2005

Above: here is a shot of an interesting evergreen shrub--Razzleberri (Loropetalum chinense rubra) which blooms as you see it here (in our new garden) through much of the gardening season. Unfortunately it is not hardy in Ontario, unless a reader in Niagara or the Windsor area wished to try it! Immediately below, while I was in Toronto in March, my good friend and host Janet Peaker (at left) had a dinner party for some old friends. Beside Janet are Antoinette Buckle, and her husband Bernie, retired tax collector for the Borough of East York. At bottom, are (left to right) Walter Godfrey, retired House Manager of the then O’Keefe Centre, Mary Langstone, retired from Sheridan Nurseries (who has recently celebrated her 90th birth-day); and my horticultural friend, Larry Sherk, now also retired from Sheridan. Author photos.

This week I’ll have a go at some questions that have come in by various means in the last three weeks. First, this one from the Forum on ICanGarden.com currently. Susan from near Halifax wrote as follows: “We initially thought we would have a deer problem due to the extensive woodland throughout our subdivision just outside of Halifax. As it turns out, we haven’t seen the deer in almost a year.

“However, we have far more intrusive visitors and need help desperately. Every one of the shrubs, bushes and perennials (with the exception of one lone smoke bush) we planted last year, was decimated by rabbits. They worked their way through Artemisia, gold-tide forsythia, mockorange, several varieties of spireas, roses, Weigela, Viburnum and their favourites were over a dozen Hosta, which were nibbled to within a half inch of the soil; not a leaf remained to be seen. The plants couldn’t establish any growth (not to mention root system) at all; as soon as there was any sign of new growth on the plantings, the rabbits invaded. They were so bold, that they were coming up on the deck, and eating right out of the planters which were on the steps. I am sure they are thanking their lucky stars that we moved onto this lot!

“Everyone thinks they are so cute and laughs at our rabbit problem and our attempts, but it is serious, we can’t afford to keep replacing plants. We have tried everything from moth balls, human hair, a noxious spray mixture of neem oil and fish emulsion, to trapping more than a dozen over the winter hoping to diminish the population. Nothing seems to work…....in fact, the rabbits seem to ignore us and just continue munching happily and multiplying. They have no fear and obviously have never heard of the expression “scared as a rabbit” because they don’t even flinch if we try to shoo them off. We have even tried chicken wire, but with such a large acreage, and so many shrubs, bushes and plantings, it is extremely unsightly to have everything covered with three-foot encirclings of wire mesh.

“Is there anything anyone can suggest? We are desperate; they are now eating the new growth on the new lawn which we put in last fall. And I am sure as soon as there is a fraction of new spring growth on the plantings, they will start on the shrubs again.”

An additional thread in the forum a couple of days later, from Nancy in zone 5 read as follows: “Our [rabbit] population explosion seems to be due to the lack of neighbourhood cats. We lost most of our good hunters in the last two years and the rabbits are now breeding up a storm. I've been unsuccessful at trapping (bought too small a trap, I think), but have some luck this year with sprinkling around a mix of Critter Ridder, blood and bone meal as both repellent and food for my bulbs. The nibbling on the smoke bush stopped when I sprayed with an animal repellent (sorry, but don't remember the brand). One of my neighbours has reminded me that she loves rabbit stew, but I'm not about to try to buy a shotgun these days, not that I'm not tempted some days.”

All right, a few comments. In my opinion, the single best ‘solution’ to rabbits is application of Wilson (Nu-Gro) Rabbit Repell. The active ingredient is Thiram and has proven to work well for most gardeners to whom I have recommended it. As far as Nancy’s use of blood and bonemeal I should point out, as an aside, the bone meal is doing nothing to prevent rabbits, and little to fertilize her bulbs. For bulb fertilizer she would be better using Holland Bulb Booster, or the Premier Technologies Myke Bulb product. Blood meal may well prevent rabbits coming around; it also sometimes keeps folks out of their own gardens due to the odour!

Nancy’s point about cats is also valid!

Judy, from a milder part of Canada (near Delhi on Lake Erie--the old tobacco-growing area) wrote to Donna Dawson with an unusual question. “I purchased 6 bareroot forsythia three years ago and planted in groups of two. I still do not get any flowers and the bushes have grown to 3' tall. I have old established forsythia that bloom. Is there any magic for the newer varieties? I just wanted a couple of groupings as we have a two-acre arboretum we planted ten years ago. These forsythia amuse me--why won't they bloom? Yesterday, I pruned out the older stock and cut down 1/3 of the clumps. There are blossoms right at the bottom. I purchased this plant material, bare root. Any suggestions would be appreciated.”

When I first read Judy’s query to Donna (Tom sent it on to me for a response), I thought perhaps you had some bushes that simply were not bloomers. That does happen with a number of trees and shrubs. My advice in that case always is to pull them out and discard them, and get new shrubs, preferably (in the case of spring flowering plants) some that are already showing bloom at the time of purchase. In that way, at least you know they are not blind and should bloom once planted in your garden.

Then I read about your pruning them and finding flowers only at the base. That is a common happening in colder climates (i.e. Ottawa), and I have even seen it happen in Toronto-area gardens after prolonged, cold winters. Flowers at the base only is a sign that the flower buds further up on the stems were killed by the cold.

The fact you have other Forsythia shrubs that have bloomed over the entire bushes only means their flower buds were hardier. For example, Forsythia suspensa and its newer cultivars bloom regularly in zone 5 climates such as Ottawa. Most others do not.

That is the only suggestion I can make. I would remind you that in pruning Forsythia, I definitely would NOT prune back thinner, young growths, but rather prune out, as close to ground level as possible, all thick, dark-coloured branches. That will give you the maximum flower bud set for the following spring. Pruning should be done only after the blooming is complete.

And finally this week, Walter Dziuba wrote to Donna Dawson about planting under a locust tree: “We have a Honey Locust tree growing in the front yard. Since we've moved there and have naturalized our entire front yard, we [have] been trying to grow an assortment of plants, flowers and my seeded annuals there, but every year we realize that our efforts have gone in vain. Knowing that the roots of this tree are very near the surface, it seems that no matter how much we water or fertilize our plants, they never really amount to much and they always [seem] to stifle in growth. Do you have any ideas on what sort of plants could be planted beneath this Locust, or is it a lost cause? With our entire front yard naturalized, it always looks like there's this patch of openness beneath the tree, and we'd love to fill it with some greenery.”

My response was as follows: unfortunately, the description “Honey Locust” is not really adequate. Is it one of the newer Gleditsia triacanthos cultivars, such as ‘Skyline’ or ‘Sunburst’? These trees’ roots are not usually considered a nuisance, especially to surrounding plantings, and the amount of shade they create is generally minimal, filtered, and thus not a problem to any plants (or lawn) beneath.

On the other hand if it is a Robinia pseudoacacia or R. hispida, their root systems are much larger, and the foliage is much denser.

I can understand annual flower transplants giving you a problem under those conditions—in order to have suitable subjects (i.e. partial-shade-lovers) grow well you would need to use generous amounts of soluble fertilizer about every two weeks through the entire growing season.

You might also consider ground covers such as Vinca minor (Periwinkle) or Pachysandra terminalis (Japanese spurge). My advice would be to try a dozen plants of each and see how they do. There are other good ground covers as well. The final solution is to spread gravel or stones tight to the tree and covering the area where you have difficulty growing plants. But I would try ground covers first.

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