Why Do Your Bushes Smell Like Cat Pee, And Should You Be Concerned?

When you picture a walk through a sunny garden, you probably imagine delicate scents like rose, lilac, or fresh rain floating on the air, but there's one all-too-common garden odor that may catch you off guard. If you catch a whiff of pungent, stale ammonia in your garden, you might assume that your neighbor's outdoor cats have been treating your bushes like a potty zone, but you may want to think twice before using cinnamon to keep cats out of your garden. The local felines might not actually be to blame, especially if you've established boxwood shrubs in your garden. Boxwood shrubs are a common pick for landscaping and gardening, but they have a foul downside that not many people know about; these popular plants can emit an odor that smells very similar to cat urine. 

Boxwoods are a go-to plant for giving gardens a lush, green feel, but this plant could be stinking up your house if you're careless about where it's planted. A poorly placed boxwood could even make guests question your cleaning habits or sabotage a future home sale. Here's why your boxwoods are suddenly smelling like cat pee, the science behind their offensive scent, and how to deal with these stinky shrubs in your garden. 

Boxwoods can be the source of an acrid, urine-like smell in your yard, but not all boxwoods are created equal. Carol Wilder, horticulture technician at Jefferson County Extension explains (via Facebook), "Many people call us and say that cats in the neighborhood are urinating in their landscape beds, and come to find out they have the type of boxwood that has that scent. Not all of them do, but some of the older [varieties] do." English boxwood (Buxus sempervirens) is one of the worst offenders when it comes to the sour stench.

On the plus side, a foul, pungent odor isn't one of the telltale signs your plant has boxwood blight. In fact, it may actually be an indicator that the bush is quite healthy and growing well enough to flower. Tiny, pale blooms that emerge in spring are the culprit, and although they are small, they can deliver a mighty odor that some describe as a cat urine-like scent. Warmth from the summer sun is also said to heat up the leaves and diffuse their oils into the air. The odor from boxwoods can also attract dogs or other animals that may urinate on the bushes and add to their unpleasant fragrance.

What should your do if your backyard has become overwhelmed with the boxwood's stench? Pruning the flowers may not be a good solution, as cutting the plant will release its acrid odors. Instead, you may want to focus on strategic planting. Don't grow your boxwoods near walkways, patios, or doorways where you're likely to notice their scent; keep them at the borders and corners of your property where they can be admired from a distance. You may also want to consider growing a few pleasantly fragrant herbs and flowers in your garden, such as rosemary, lavender, or rose to mask the smell. 

The best way to avoid boxwood stink in your yard is to plant an odorless variety. Asian varieties (Buxus microphylla) and hybrids like 'Green Velvet' won't stink up your yard. If you're unsure while shopping at a nursery, horticulture technician Carol Wilder recommends leaning close to the bush and brushing your hands over the foliage to release its scent, if there is any. Alternatively, you can skip the boxwoods altogether and opt for a similar-looking landscaping shrub, such as yew, pryracomeles, or inkberry holly. If you're still a fan of classic boxwoods, there are some folks who don't mind the smell or maybe even enjoy it, claiming it smells more like a deep, summer country garden or woodsy musk than a dirty litterbox. Perhaps beauty is in the nose of the beholder.