What Bushes Smell Like Cat Pee? | Plants to Sniff Out

You walk past a bush on a warm afternoon and catch a whiff that stops you cold. That unmistakable ammonia-like smell — is a neighborhood cat using the shrub as a personal litter box? Maybe not. Some of the most popular landscaping plants are known to produce an odor that many gardeners describe as strikingly similar to cat urine.

The answer to the question of what bushes smell like cat pee isn’t a single plant but a handful of common varieties. English boxwood, certain junipers, and yellow alyssum are the usual suspects. The smell has nothing to do with felines — it’s a natural chemical release from the leaves, especially on hot, sunny days.

Why Some Bushes Smell Like Cat Urine

The biology behind the smell is simpler than you might think. Boxwood leaves contain volatile oils that are largely undetectable until the sun heats the foliage. When temperatures rise, these oils vaporize, releasing a pungent, ammonia-like scent that many people associate with cat urine.

This isn’t a sign of disease or distress for the plant. It’s a natural characteristic of certain varieties, most notably English boxwood (Buxus sempervirens ‘Suffruticosa’). The smell is strongest on still, hot afternoons when the air doesn’t circulate the oils away.

Which Junipers Are the Worst Offenders

Junipers are another group that can produce this odor. The Pfitzer juniper (Juniperus x pfitzeriana) and savin junipers are frequently mentioned by gardeners as having a distinct cat-urine-like scent. The smell tends to be strongest after pruning or on humid days, according to forum discussions.

Why Gardeners Want to Identify These Smelly Shrubs

Most people plant bushes to make their yard more inviting, not to create an unpleasant mystery odor. If you’ve been blaming a neighbor’s cat for a smell that turns out to be a shrub, you might have wasted time and effort on the wrong cause. Identifying the plant helps you decide whether to keep it, relocate it, or replace it with a non-smelly alternative.

• English boxwood (Buxus sempervirens ‘Suffruticosa’): This classic landscaping shrub is the most commonly reported culprit. Many gardeners confirm the sun-heated leaves release that distinctive ammonia scent.
• Pfitzer juniper and savin juniper: These spreading junipers are known to produce a cat-urine-like odor, especially when pruned or on humid days.
• Yellow alyssum: Unlike its sweet-smelling relative sweet alyssum, this perennial’s flowers are notorious for smelling like cat pee. Some gardeners also compare the scent to aged cheese.
• Prostrate juniper: A low-growing groundcover that some gardeners say carries the same pungent scent, though opinions vary on which juniper varieties are the worst.

Once you know which plant is causing the smell, you can take action. If the bush is otherwise healthy and well-placed, some gardeners learn to accept the occasional scent on hot days. If it’s near a patio or entryway, you might choose to remove it.

How to Confirm the Bush Is the Source of the Smell

Before you blame the shrub, it helps to rule out actual cats. A simple test can settle the question. Crush a leaf from the bush and smell it directly. Many gardeners find this quickly confirms whether the plant is the source.

If the crushed leaf smells like cat urine and the bush is in a spot cats cannot easily reach (such as a raised planter or enclosed bed), the plant is almost certainly the cause. The UBC Botanical Garden forums feature a long discussion thread on this exact topic — the juniper cat urine smell thread includes dozens of gardener reports confirming the phenomenon.

If the smell only appears after rain or on hot days, that’s another clue pointing to the plant’s natural oils rather than animal activity. Boxwood and juniper both tend to release their odor most strongly when heat and humidity are high.

What to Do If Your Bush Smells Like Cat Pee

If you’ve identified the culprit and the smell bothers you, you have several options. Some gardeners choose to embrace the plant’s natural characteristics, especially if the bush is otherwise attractive and well-suited to the landscape. Others prefer to remove or replace the plant.

1. Confirm the source: Crush a leaf and smell it directly. If the odor is clear, the plant is the cause. Rule out actual cat activity by checking for signs like digging or spraying.
2. Try a natural odor treatment: For removing pet urine smell from plants or soil, a baking soda paste can help. Mix baking soda with water, apply to the area, scrub with a stiff brush, and rinse thoroughly. This method is described by pet care sites like Rover for general yard odor control.
3. Consider replanting with odorless alternatives: Sprinter boxwood (Buxus microphylla) is a fast-growing boxwood variety that does not have the notorious boxwood odor. Sweet alyssum is a fragrant alternative to yellow alyssum.
4. Prune and maintain differently: Some gardeners find that keeping boxwood and juniper pruned to allow better air circulation reduces the intensity of the smell on hot days.
5. Accept the seasonal nature: For many people, the smell only appears a few days a year on the hottest, stillest afternoons. If the bush is in a less-traveled part of the yard, it might not be worth replacing.

The choice depends on how much the smell bothers you and where the plant is located. A boxwood near a front door might be more noticeable than one tucked into a back corner of the garden.

Odorless Alternatives to Smelly Shrubs

If you love the look of boxwood but can’t tolerate the smell, you’re in luck. Several boxwood cultivars and other evergreen shrubs offer a similar appearance without the pungent odor. Sprinter boxwood is one popular choice that many gardeners report as odorless.

A Yahoo Lifestyle article on garden shrubs that smell like cat urine confirms that the English boxwood odor is well-known among gardeners, and that alternative varieties exist. Other odorless options include Korean boxwood (Buxus sinica) and certain Japanese boxwood cultivars.

If you’re shopping for new plants, reading reviews from other gardeners can help you avoid surprises. Many online nursery sites include customer comments about fragrance, and local garden centers can often tell you which varieties their customers have flagged as smelly.

The Bottom Line

A few common landscaping bushes — English boxwood, Pfitzer juniper, and yellow alyssum — are known to produce a cat-urine-like odor when heated by the sun. The smell comes from natural leaf oils, not from actual cats. If the odor bothers you, consider replacing the plant with an odorless variety like Sprinter boxwood or sweet alyssum.

If your pet seems drawn to the bush or you suspect the smell might be coming from actual urine rather than the plant, a quick sniff of a crushed leaf can confirm the source. Your veterinarian can help rule out any health-related reasons your cat might be urinating on specific plants in your yard.