How To Prune, Trim & Maintain A Live Topiary Plant

Trimming A Topiary Plant

First, so you'll know, this article is not about creating a topiary plant from scratch. Instead, it's about the easy part: how to trim an existing topiary plant to maintain its original shape. 

So you were shopping on Wilson Bros Gardens or you were at your local nursery and garden center and saw a spiral, pom pom, poodle tier, or other interesting topiary plant and thought it was so cool you just had to have one. And you'd be right, living topiary plants are cool. 

So you got home and planted it and now it's 6 or 8 months later and your topiary plant isn't so cool anymore. New growth emerged and now what was once a perfectly sculpted spiral is looking a bit shaggy, like it's sprouted a beard. You'd like to trim it but you're afraid to touch it for fear of destroying the shape of the plant...or the plant itself. No problem, continue below to find helpful tips that'll have you trimming topiary plants like the pros so you can keep them looking like they did when you first brought them home.

How To Trim A Topiary Plant

Trimming a topiary plant is fairly straightforward. That said, there's some things you should consider before beginning.

When and how often to trim?

How often you trim your topiary plants will depend on climate, fertilization and the typical growth rate of a specific plant species. A privet plant grows at 10 times the rate of a boxwood. Faster growing species will require more frequent trimming. Bottom line, trim your topiary plants as needed to keep them looking nice. 

The more frequently you trim your topiary the easier it is to keep the plant in its intended original form. This doesn't mean you want to always trim the plant back to its original size, because all plants need to be allowed to grow some in size. What it means is that by trimming more frequently, maybe 2 to 3 times per year, rather than just once a year, it makes it more easy to see and follow the original form. This is especially true with spiral form topiary and other more complex shapes and forms. 

If you allow a topiary to grow too much before giving it a trim, such as a spiral form, the plant will revert back to its natural form, which is a solid column, pyramidal, round or cone shape. At this point, you might have to have an eye for carving 3-dimensional shapes in order to reshape what was once a spiral back into a spiral, and this is no easy task for someone who doesn't have the eye for it. You might be better off hiring a professional who is highly skilled at this pruning art form, and then make sure to trim your topiary more often!

Caution:  To avoid damaging new growth that could be damaged by an early frost, cease all trimming of you topiary plants two months prior to the average first-frost date in your area. 

Examine the plant

Before trimming your topiary, take some time to study and examine the plant you intend to trim. Look beyond the shaggy surface growth and put in your mind's eye the original shape of the topiary. 

While studying your topiary, if you see any damaged or dead parts cut these off with a sharp pruners. Damaged or diseased plant parts should always be removed as they occur.

Note:  If a plant part looks diseased, to prevent the spread to other parts of your topiary plant, it's a good idea to dip your pruners into a solution of alcohol. The advantages of alcohol (ethanol or isopropyl) to sanitize your gardening tools is that it is instantly effective and can be used as a wipe, and you don't have to rinse the product off. To disinfect your tools with alcohol you can either wipe or dip them in a solution that is 70–100% alcohol. 

To grow or not to grow?

Before giving your topiary an all-over trim, decide if you are going to trim the plant back to its original size and remove all new growth, or if you want to allow your plant to keep some new growth to increase its size. I always suggest allowing the plant to keep a little of its new growth. For example, if your topiary has added 3 inches of shaggy new growth, maybe trim this back by 2 inches or so. 

Trim away!

VERY IMPORTANT!  If your topiary plant is a pine species, to avoid damaging or killing your plant, there is a more specific pruning method that should be followed. Before pruning a pine read our article: How To Prune A Pine Tree Or Pine Shrub

To trim your topiary plant, avoid using long-bladed hedge trimmers or hedge shears, which might not allow you to cut properly from various angles. We use a sharp pair of bypass hand pruners or handheld clipping shears to trim back the new growth to desired length. 

Start trimming your topiary plant from the top down. If you're nervous about trimming off too much growth, maybe start with a light trim of  just a small section at the top of the plant. For example, if your plant has added 4 inches of shaggy new growth since the last trimming, maybe remove an inch or two of growth from the small section. If you decide that won't be enough, remove another inch of growth from the same small section. When you've decided enough is enough, then trim the same amount off the rest of the plant.

Give it a drink

If the soil is dry, deeply water your topiary plant after you finish trimming it.

Other Topiary Trimming Tips

With the exception of pine species, if you accidentally cut too much foliage away; beyond the point of green growth, don't worry too much about it. The trimming usually stimulates new growth that will fill in quickly. That said, some coniferous evergreens, such as junipers, do not respond well to pruning beyond a point on a stem or branch in which there is no foliage/leaves.   

So as to make clean cuts that won't brown foliage tips, keep the blades on your trimming tools as sharp as possible 

If possible, prune topiary trees on a cloudy day. Too much sunlight on freshly cut branches of some plant species can cause the leaf and stem tips to turn brown.

Related Articles

Plant Long & Prosper!

Questions? Contact Us!