- by Grey County Master Gardeners

Would you describe your garden as “full”, or “lush”? Be honest now; are your shrubs so large they are hiding the plants around them, but no longer flower as profusely as they once did? Are your perennials growing into one another? Do you have so many self-seeded volunteers that your original planting scheme has long since disappeared? Is the lawn threatening to engulf your flower beds? I hate to tell you but your garden isn’t just full, it’s overgrown and in need of rejuvenation.

If you have a large garden, don’t try to work on the whole thing at once. Focus on one section at a time. You may want to start with the section of the garden where you spend most of your time relaxing or socializing, or you might prefer to prioritize your entrance garden. By completing one area before moving to the next you will be able to see concrete results of all your hard work.

Pruning: Let’s start with those “lush” shrubs. Many overgrown deciduous shrubs, especially those that send up new growth from the base, respond well to drastic “rejuvenation“ pruning, which is cutting the shrub to about 12 inches from the ground. This is best done as early in the spring as possible while the shrub is still dormant; however, if your shrub flowers early in the year such as forsythia, you will be forgoing whatever blooms it still puts out until next year. You can wait and prune immediately after flowering if you want to see those early blossoms. Shrubs which respond well to this treatment include Forsythia, Honeysuckle (Lonicera), Hydrangea arborescens (such as “Annabelle”), Weigela, Red-twigged Dogwood (Cornus spp.), Willows (Salix spp.), and Elderberries (Sambucus spp.).

During the year your shrub will put out a lot of new growth. Next year in the late winter/ early spring prune the shrub by cutting off the weakest looking stems at the base, leaving a strong framework for future growth. If you have any doubts about taking such drastic action, you can accomplish the same result over 3 years, removing not more than 1/3 of the old growth at ground level each year.

Unfortunately most conifers cannot be rejuvenated in this way, as they do not generate new growth to replace branches that have been removed. In some cases it may be necessary to replace a conifer that has become significantly overgrown or misshapen. Yew shrubs (taxus) are the exception, and respond to drastic pruning with new growth.

Edging: The next step is restoring a clean edge between the lawn and flower bed. You can use a tool made specifically for edging or a sharp spade. In either case, remove a band of sod and grass roots that are threatening the plants. Even an overgrown bed looks a lot better with a clean edge.

Rejuvenating the Design: Now is a good time to step back and take a look at the garden, before you start working in the planting beds. Does the combination of plants create an interesting garden that pleases the eye or does the design of the garden need a bit of rejuvenation as well? Most successful gardens have plants of various sizes and forms. A combination of foliage types or textures is also important to make sure your garden isn’t boring. Maybe you have too many plants of similar shape & foliage.

A focal point can also add a bit of drama to a garden. Anything that catches the eye, such as structural plants, birdbaths, striking pots can act as a focal point. Just remember that focal points should be used sparingly.

Perennials: Now it’s time to get rid of those weeds and get the overgrown perennials under control. This step can be done in the fall if you want to move on to other garden chores; however, I prefer the spring when the plants (and weeds) are smaller and it’s easier to dig and divide. If the weeds and grass have taken over, decide what plants you want to keep and rescue them before going any further. Identify the best specimens, and dig them up, dividing the clump as necessary. Make sure the plants that are going back in the bed or to be used elsewhere in the garden are totally weed and grass free, or all your work will start to unravel. Remove or wash all soil from the roots so you can see and remove all of those persistent grass roots. You will need to keep these plants safe until they can be replanted. If you will be able to replant them the same day, they can be left in the shade, making sure their roots are covered. If it will be longer, they should be heeled in someplace or put in pots.

There are a few perennials that don’t like this approach, as they don’t like to be disturbed. Perennials with deep tap roots such as oriental poppies (Papaver orientale), blue false indigo (Baptisia australis), baby’s breath (Gypsophila) and Lupins would prefer you left them alone. If possible clean up around them and let them be. They don’t need dividing; although, unless you are careful about deadheading, the oriental poppies will be generous with seedlings. Lilies are also a bit particular and their bulbs should be dug, divided and moved in the fall when they are dormant.

Finishing up: You’re almost done! The next step is to dig up everything that’s left, making sure you are careful to get all weed and grass roots. You may want to discard the plants left in the bed as it will be difficult to ensure they are free of weeds & grass roots. The soil probably can use some rejuvenation as well, so treat it to a thick layer of compost before replanting the perennials you divided and any of the self-seeded volunteers that you have rescued. Why not reward all your hard work with a visit to a garden centre for something new and different to perk things up? Once everything is planted and watered, cover the bed with about 3 inches of mulch. Now relax and enjoy your new garden.