Documents: Garden Design:

Lilacs, Roses, Clematis and Shrubs

Problems with over-grown lilacs and what to do; don’t be overly concerned about how you prune roses and just when to move roses, Clematis and shrubs!
by Art Drysdale
by Art Drysdale


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

June 18, 2006

Above: Fiskars long-handled Power Lever® tree pruner, and below, a ‘Versailles’ rose bush with the longest blooming stalk the author ever produced in his garden!. Author photo.

Jennie Gulinski, a regular listener, wrote from Burlington ten days ago with a couple of fairly involved questions. Here they are: “I listen to AM740 every day, driving to work and back. I used to work midnights and listened to the station all night and going home in the mornings. Now I have been transferred to afternoons and luck would have it that I only hear the start of your gardening advice and usually miss the conclusions.

“There are two issues I wish to ask about; First, I have three old lilac trees. You mentioned pruning them now, however they are really old and bare at the bottom and too tall at the top. Also all through the lilac trees, (because they have surpassed being bushes) there are old, broken bare branches, right up to the top. I'm too old to climb up ladders to trim them. I've taken the bottom blooms off but do not own a big enough ladder to remove them from the top. I bought this house three years ago and I'm positive these bushes have never been attended to nor have they been pruned at any time. Someone planted them and left them to grow and bloom.

“I'm thinking that I might cut them out and plant dwarf lilac bushes. Could you recommend a good variety, also when is a good time to cut the existing trees down and replant the new ones? Or can these three old trees be salvaged in any way. What would you recommend?

“Second; Last year I bought two rose bushes. They are not hybrid and are very sturdy. The roses bloomed right through to the end of September. Blooms started to open up right now. Apparently they have a long blooming sea-son. Around the middle of August last year both bushes each grew a long stem about 5' to 6' tall. I needed to put burlap around them to protect them from the street salting in the winter. They are up near the house and not near the street but my father did this and he knew about roses so I decided to do the same. I cut each of the long stems very low and prayed I didn't kill the bushes.

“In the early spring, (April) I needed to prune them down, but I wasn't sure how low to do it, so I called the Royal Botanical Gardens and spoke to a rose expert. He advised me to cut them down low and to remove some of the stems near the ground leaving them with only 5 to 6 stems each. Being inexperienced I did cut them down but I worried I'd do harm to the bushes if I didn't do it properly so I left them as they were, understanding that rose bushes are very sensitive.

“My neighbour across the street told me I didn't cut them low enough. Well she was right, you should see them, they are huge about 5' tall and about 4' wide. I am concerned how huge they will get before the season is over. Is there any advice you can give me as to what to do with these roses at this late date? Right now they are full with new buds that will open soon. The bushes bear truly beautiful blooms. The sad thing is that I let them get to the state they are in because I have arthritis in my knees and hands; it was very difficult to get out during the many days of rain we have had. And so they grew. Thank you for any advice you can offer.”

Well Jennie, and many others who have similar problems with lilac shrubs/trees, your plants definitely need attention. I fully realize you cannot climb a ladder to prune them, but maybe you could use a long-handled pruner such as Fiskars (and other companies) make. The Fiskars long-handled Power Lever® tree pruner, for example, extends to 4.3 metres (14’) and is made of lightweight Fiberglas and thus reasonably easy to handle. Failing that, then I guess you’ll have to try to find a neighbourhood youth who can climb a ladder for you and do all the trimming.

Obviously all of the old dead wood needs to be removed, and in addition, I would remove all of the oldest (thickest) branches right from the base of the plant. A saw, such as that which comes with the Fiskars pruner (see photo here) will be needed for this.

This work could be done at any time from now until late summer, or you could wait until early next spring, before the foliage comes out. If after cutting out the dead and oldest wood, you still think the bushes are too high, you could shorten the newer, thinner growths by as much as one-half if you wish. Regardless of when you do the pruning, if you are cutting the shrubs/trees back severely, you will curtail most of the flowers for the next season. They should, however, flower well the following year. After pruning, I would recommend you add some horticultural lime to the soil, and also apply some general fertilizer such as Liquid Growth Garden Bloom to the foliage if the pruning is done while they are in leaf.

As to taking out the shrubs/trees, that is likely a more difficult task than the pruning, as lilac root systems are usu-ally extensive. It is definitely possible, but you’ll need help! New plants that are dwarf? Most lilac shrubs grow to about three to five metres in height naturally, that is about ten to 15 feet! There are some dwarfs such as dwarf Korean lilac (Syringa meyeri ‘Palibin’) which I grew for years in my front garden in Toronto. Others you might wish to look for are Miss Kim (Syringa patula ‘Miss Kim’), Prince charming (S. ‘Prince Charming’) and sugar plum fairy (S. ‘Sugar Plum Fairy’™). By the way, it is generally agreed that the single best time for transplanting lilac shrubs is in the late fall.

Now to the roses! It seems to me you have some very good cultivars there. You should not get overly worried about pruning roses. Just keep a couple of guidelines in mind. First, do little or no pruning in the fall (the exception to that would have been your very tall shoot which could have been cut back to about 75 cm [3’] last fall); when pruning in the spring, prune all canes down to about 15 cm (6”), and cut away entirely any thin branches (those less than pencil thickness). The old theory about pruning was to prune each thick cane at an outward-facing bud which then encourages a more open centre to the bush and better growth.

What to do now; I would cut some of the taller-growing branches back severely as their bloom finishes, but again, do not be overly concerned about how much they grow. The photo here of the cultivar ‘Versailles’ growing in my Toronto garden a number of years back will give you something for which to aim! Good luck!

While I am dealing with questions from Toronto listeners, I may as well respond to Gerry Kee’s question: “Hi Art--I listen to you every week on AM740, and thoroughly enjoy your show (I've been a fan since your Toronto days on CFRB)--also purchased the "Rainstick" which is as great as you said, and your book Gardening off the Ground, which is most helpful for containers.

“Please advise re: the following--can I transplant a Burkwood viburnum which has finished flowering, a Clematis alpina ‘Constance’ which bloomed early this spring, and a climbing rose which is in leaf but no buds yet or must I wait until fall? I also have a small lilac to move, but have been told I must wait until very late fall--do you agree? I live in Woodbridge, just north of Hwy. 7, which is generally zone 5. Will eagerly await your response. Thanks.”

The answer to each of Gerry’s questions is basically, yes, wait until fall. With the alpine clematis, I even question whether I would move that in the fall; instead I would prefer to wait until early next spring. The rose should move well late this fall (if it has not lost all its leaves when you move it, then remove them mechanically) and ditto the lilac. Though it can be moved earlier, the absolute best time to move lilacs, as mentioned above, is in late fall; i.e. mid November, or later, depending on climate conditions. You could try to move the Viburnum burkwoodii now—treating it as a “containerized plant”; i.e. lifting it carefully with a fairly large ball of soil intact. However, if you wait until late fall, it should move easily treated as virtually a bare-root plant.


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