Confused about when to trim your shrubs? Here’s what to prune now and how to do it
The first week of February is all about forsythia and pruning.
Forsythia is the bright yellow shrub ready to burst into blooms and you can prune it now to force the flowers into an early show indoors. Just cut bare branches from your forsythia and place in a vase of warm water indoors. In a few weeks to a few days, you’ll fool Mother Nature into an early bloom.
February is also when you can begin the general pruning of dormant fruit trees and start garden cleanup. Just be careful when tramping about the soil and lawn if the ground is frozen or very wet. This time of year the soil can be easily compacted from heavy feet. Professional gardeners will sometimes place a sheet of plywood on the ground before standing on soft soil to do their winter pruning. An advantage of this is that the pruning crumbs will fall onto the plywood sheet, making for quick cleanup.
Pruning always stimulates growth, so don’t go getting all snippy with tender plants that you want to stay dormant until spring. A second warning is that not all trees and shrubs need pruning and if you prune spring flowering trees and shrubs in early spring, you will be removing flower buds along with branches.
Confused? You are not alone. Here are some of the most-asked pruning questions this time of year:
Q. When do I prune my roses? I have heard everything from February first to late March. I was even told at a nursery that I never need to prune my shrub roses. Help! — N.G., Bellevue
A. Here in Western Washington, the general rule of green thumb is to prune roses back by at least one third in early spring. So perform the surgery anytime in February and March.
Cut back by at least one third if you have large shrub or landscape roses, but to rejuvenate an old rose, you can cut it back to one foot in height and new growth will emerge this spring with blooms this summer.
The only roses that do not respond well to severe pruning are climbing roses. Climbing roses can be tidied up by shortening their side shoots but leave the long canes alone to arch or drape over a support system.
Roses are tough plants. Thin out anything dead, diseased or damaged, and remove branches that cross or rub against one another. Roses barely notice if you make the cut in the wrong spot and shrub roses or landscape roses look better with a yearly haircut. But like most roses, they will still bloom if you don’t prune at all.
Q. Is February the time to prune fruit trees? I have some very old apple trees. — J.H., Enumclaw
A. Yes to late winter pruning of fruit trees, but don’t go too crazy. Pruning stimulates growth and an apple tree pruned too severely will send up water sprouts or thin upward reaching branches from the center of the tree. To avoid this, remove less than one quarter of the branches, opening up the crown and shortening long branches. You won’t restore the shape of your trees in a year, so slow down and take your time. Aim to reshape the tree over 3 or 4 years.
Q. Can I prune overgrown rhododendrons this month? Asking for a friend. Anon
A. You can, but the rhodies won’t like it. Spring flowering shrubs like rhododendrons and azaleas prefer to be pruned after they flower. That is when they are putting on strong new growth and you get to enjoy the flowers before you make the cut.
To renovate a giant rhododendron, consider cutting back one third each year rather than a drastic beheading. Like most shrubs, rhododendrons do best with little or no pruning. Giving your plants room to grow is best for the plants and easiest for the gardener.
Q. When should I prune my Pee Gee hydrangea? It flowered well last summer but it had many small flowers rather than giant flower heads. — E.G., Sea Tac
A. Grab a saw and start removing branches from your Hydrangea paniculata or Pee Gee hydrangea this month. The fewer branches you leave on this type of hydrangea, the larger the creamy, pointed blooms will be. Remove side shoots and shorten main branches to create a strong framework for the huge flowers.
Like all hydrangeas, you do not need to prune your Pee Gee hydrangea to keep the shrub healthy. The reason to do some selective pruning in early spring is to help shape the plant and encourage larger blooms on fewer branches.
Marianne Binetti has a degree in horticulture from Washington State University and is the author of several books. Reach her at binettigarden.com.