Garden Performance and Growth Habit Issues
Many gardeners are drawn to catmint's long flowering season and drought tolerance. However, these benefits can come with several drawbacks related to its growth habit and garden performance. Understanding these issues can help in selecting the right variety or preparing for proper management.
Overly Aggressive Spreading
Some older varieties of catmint, particularly the species known as catnip (Nepeta cataria), can be prolific self-seeders. While not technically considered invasive in most regions, their vigorous spreading can lead to them overtaking garden space and crowding out less robust plants. This requires regular intervention, such as deadheading spent flowers, to prevent unwanted seedlings from popping up everywhere. Selecting sterile or clump-forming varieties, like the popular 'Walker's Low' (Nepeta x faassenii), can mitigate this issue.
Floppy and Leggy Growth
Another common complaint, especially with older catmint cultivars, is its tendency to develop floppy or leggy growth. This can cause the plant to lose its attractive, mounded shape, resulting in a messier appearance. Factors contributing to this include overly rich soil, too much fertilizer, and insufficient sunlight. In warmer climates, high heat and humidity can also cause plants to struggle and look wilted. Shearing the plant by half after its first major bloom cycle can encourage a bushier habit and a second, neater flush of flowers.
Poor Drainage Sensitivity
Catmint thrives in well-drained soil and is exceptionally drought-tolerant once established. The major disadvantage here is its intolerance for heavy, wet soil, such as clay, where it is prone to root rot. Gardeners with heavy soil must amend it with organic matter or grow catmint in raised beds or containers to ensure proper drainage.
Susceptibility to Powdery Mildew
While generally resistant to most pests and diseases, catmint can be susceptible to powdery mildew, particularly during hot, dry summers. This fungal disease appears as a white, powdery coating on the leaves and can lead to dieback. Ensuring good air circulation and removing affected foliage promptly can help manage this problem.
Potential Issues for Pets and Wildlife
Catmint's name highlights its most well-known interaction, but the consequences aren't always ideal. There are several considerations for pet owners and those who want to manage local wildlife.
Cat Attraction and Plant Damage
True to its name, catmint, and its more potent relative catnip (Nepeta cataria), strongly attract many cats. For gardeners, this can be a significant drawback. Cats may roll, chew, and lie on the plants, causing crushed stems and a flattened, unsightly appearance. While this usually doesn't kill the plant, it can ruin its aesthetic appeal. This is especially problematic for those who don't want to encourage neighborhood cats in their garden.
Minor Toxicity Concerns for Pets
Though catmint is not considered highly toxic to cats or dogs, ingesting large amounts can cause mild gastrointestinal upset. Symptoms may include vomiting or diarrhea. Cats are more likely to be attracted to it, but dogs may also nibble on the leaves. While serious incidents are rare, pet owners should still supervise their animals around the plant, especially if they are prone to eating foliage.
Aggression in Cats
In some instances, the nepetalactone compound in catmint can cause some cats, particularly males, to become mildly aggressive or irritable. If you notice aggressive behavior, it is best to remove the catmint and find an alternative enrichment source for your pet.
Table: Catmint vs. Alternatives
| Feature | Catmint (Nepeta) | Lavender (Lavandula) | Russian Sage (Perovskia) |
|---|---|---|---|
| Potential Floppiness | High (in older varieties, rich soil) | Low | Low |
| Invasiveness Risk | Low (some self-seed) | Very Low | Low |
| Cat Attraction | High | Very Low | Very Low |
| Drainage Needs | High (well-drained soil) | High (very well-drained) | High (very well-drained) |
| Pollinator Attraction | High | High | High |
| Susceptibility to Mildew | Moderate (in poor conditions) | Low | Low |
Conclusion
While catmint offers many benefits, including its beauty and resilience, understanding its potential disadvantages is key to successful gardening. The primary issues are its tendency to become floppy or spread aggressively, especially with older varieties, and its attractiveness to cats, which can lead to plant damage. In certain conditions, it can also suffer from powdery mildew or root rot due to poor drainage. Most of these issues can be mitigated by choosing sterile, modern cultivars, providing the right growing conditions, and performing regular maintenance, such as shearing after flowering. For pet owners, monitoring animal behavior around the plant is important, although serious toxicity is rare. By weighing these potential drawbacks against its many positive attributes, you can make an informed decision about whether catmint is the right fit for your garden. If problems arise, alternatives like lavender or Russian sage might offer similar aesthetics with fewer headaches.
Other Considerations
For gardeners seeking alternatives, other drought-tolerant perennials can offer similar colors and pollinator benefits without the same pitfalls. For example, salvia or lavender might provide a neater, more contained growth habit and will not attract cats in the same manner. Using catmint in a contained environment like a container garden is another strategy to control its spreading and floppiness. This allows you to enjoy its beauty while keeping its less desirable habits in check.
