8 Plants You Should Never Grow in a Small Yard, According to Horticulturists

Lilac

Lilac is beloved for its showy, fragrant blooms, and seems like a no-brainer for a small yard. However, its upkeep can be demanding. "I'd avoid the Syringa species, as that can become very, very large and require yearly pruning," says John Lorusso, a horticulturist and master gardener at the University of Connecticut.

This advice also applies to buckeye (Aesculus), and bottlebrush (Melaleuca) species. Depending on your space, a dwarf lilac may suffice, but they can still become several feet wide and several feet tall.

Willow

Willow trees look majestic, and have long, sometimes drooping branches, and thin, feathery leaves. They're often found along riverbanks, in swamps, and near ponds, because they absolutely love water—in a small yard, it may not be feasible to keep up with their hydration needs. Willow trees also have a huge, powerful root system that needs a lot of space.

"Their roots tend to grow in the upper profile of the soil, which can then interfere with other planting, and can literally break sidewalks and driveways," says Lorusso. "Willows have the added challenge that they are the least able to tolerate high winds, which can cause them to fall over after a few years." Obviously, this isn't ideal, especially if your house is nearby.

Peppermint or Spearmint

Mint plants smell great and can withstand some drought. They love sun, and if the conditions are right, they can grow vigorously. "It's a great addition to a culinary herb garden, but don't plant them in the ground, or they'll quickly colonize most of your yard," says Charlotte Glen, horticulturist and master garden program manager at North Carolina State University.

Instead, if you want fresh mint for tea or pesto, keep it in a container with other herbs. "Use large containers, and place them on a solid surface, such as brick or concrete," says Glen. "That way they don't have contact with the soil, which minimizes the chances of their roots escaping from the holes in the bottom of the pot."

Golden Bamboo

In certain situations, bamboo makes for a good garden screen, as it can grow to be incredibley dense. In a smaller yard, though, it's hard to keep bamboo contained—and it may even cause damage to your property.

"Golden bamboo is an aggressive spreader that has been know to emerge through concrete and home flooring, and is considered invasive in several states," says Glen.

However, she adds, it's important to note that's not true of all bamboo. "There are non-invasive, clumping bamboo species and cultivars," she says. "Be sure to do your research when selecting bamboo varieties!"

Leyland Cypress

Like bamboo, Leyland cypress is usually used as a fast-growing screen that fills up empty space quickly. But if your yard is especially small, this tree will take up most of the available plot.

"As with many fast-growing evergreens, Leyland cypress grows very large, up to 60 feet tall and 10 feet wide, and quickly overwhelms smaller spaces," says Glen.

However, even in larger yards, this plant may be one to avoid. "Due to its overuse, it has also developed many serious disease issues, most of which cannot be managed," she adds. "They can cause the plants to die within a few years of symptoms first showing."

Green Giant Thuja

The green giant thuja has some of the same problems as the leyland cypress, so you may want to think twice before planting it in a smaller yard. "It has fewer disease issues, but is equally large and fast-growing, and will quickly overwhelm small spaces," says Glen.

She notes that other varieties that aren't as fast-growing, like Holmstrup, as well as smaller evergreens, are a much better choice.

Coral Honeysuckle

Coral honeysuckle should be avoided in a small yard. Its vines may have a lovely scent, and it will attract pollinators, but it will also overtake any structure in its path.

"While these are lovely native vines, they will easily climb to 20 feet and quickly devour a small trellis or mailbox," says Glen. "When selecting vines, be sure to choose varieties that match your support structure, and that aren't known to be invasive."

Bee Balm

Some perennials spread aggressively via rhizomatous root systems, says Glen. Bee balm is one example, so while it attracts a wide range of pollinators and is pleasantly fragrant, it will also spread across a small area and overtake less aggressive plants.

So while these plants are great if you need to quickly fill a large, natural area, they're too aggressive for smaller spaces.