At this time of year I receive hundreds of question on the subject of pruning, through my website (www.markcullen.com). Perhaps gardeners know instinctively that this is an ideal time of year to get many of our plants under control and to encourage a raft of fresh new blossoms next year by pruning in early fall.
Here is a rundown of how to prune and why you should bother.
Perennials. As your perennial flowering plants (technically ‘herbaceous perennials’ vs. ‘woody shrubs’) finish their flowering cycle they are busy pushing the limited energy from their roots into seed production. This is, after all, the primary purpose of flowering in the first place. Fact is, Mother Nature created flowers to attract pollinators, not so that we can pick them to put on the kitchen table. Once pollinated and fertilized the flower matures into its’ seed production phase.
Remove the spent flowers and flower stems of all perennials that have finished flowering this summer. With some luck you will get a ‘reflowering’ period later in the season. Do not cut them down to the ground: just the flower and several inches of stem will do.
For late flowering perennials, I leave them standing all winter long to add interest and to provide seeds for song birds.
Ornamental grasses are generally best cut down in April.
Roses. I remove the spent flowers and a few inches of stem after they have flowered. I have been doing this since the first ‘crop’ of flowers finished in late June. September becomes a great time of year for a second showing of blossoms. When they are finished I let the plant stand as is all winter unless it is over one meter high, in which case I cut them down to about 80 cm to prevent them from ‘whipping’ in winter winds and risking a break at the root zone of the plant.
Flowering Shrubs. Much like perennials, it is best to remove the spent flowers after they bloom to maximize the blooming potential next year. This is a great time of year to get flowering shrubs under control that have already bloomed. Like perennials, flowering shrubs lend themselves to pruning for several weeks after blooming.
Be bold – you are the boss.
If you have shrubs that are gangly, out of place or just generally taking over where they have no business doing so, this is a good time to show them your hand and get pruning. Often I find new gardeners timid about this job but I assure them they need not be. Take up to 1/3 of the growth off a woody shrub without fear that you are damaging the plant. Of greater importance is HOW you prune your shrub. I prefer the practice of pruning individual stems from the plant by reaching into it with a sharp pair of hand pruners and removing one stem at a time. This will open the shrub up to sunlight and improve the air circulation. New growth will occur from the centre of the plant where it will rejuvenate the plant and encourage new blossom buds to develop this fall.
‘Hand pruning’ may take more time, but the results are much more satisfying and of greater benefit to the health of the plant in the long haul.
As with most jobs: the quality of your work will be determined by the quality of the tools that you use. Not only am I a firm believer in using quality tools in the first place but the premium that you pay for them is only worth it if you take care of them. Where pruning equipment is concerned this means:
• Hand pruners should be sharp and clean. Invest in a high carbon steel sharpener, lubricating oil and do not leave them out in the weather.
• A ‘pruning saw’ is distinctly different from the cross cut or rip saw in your basement. A good quality ‘green wood’ saw has teeth arranged in such a way as to cut on the fore stroke and the back stroke. It is important to keep it clean and sharp.
• Shears Sharp and clean is the theme, once again. To sharpen grass or ‘hedge’ shears I use a new (never rusty) bastard file for the first sharpening and finish with a high carbon steel sharpener or sharpening stone with oil. Lubricate the hinged joint and sharpen every time you use them. If the handle is wooden I rub it down with an oily cloth two or three times a season.
• Loppers (for cutting limbs from trees) need to be lubricated and cleaned every time you use them also. Make sure that the rope used to ratchet the cutting mechanism is in good repair.
Always store your cutting tools indoors, out of the weather.
Mark Cullen appears on Canada AM every Wednesday morning at 8:40. He is spokesperson for Home Hardware Lawn and Garden. Sign up for his free monthly newsletter at www.markcullen.com.