There’s much to love about hydrangeas, whether it’s their voluminous blooms, vast range of species and colors, or varying heights. This all means the options for incorporating hydrangeas into your yard are nearly endless. But, if having so many options to choose from sounds more intimidating than invigorating, Linda Vater, plant expert for Southern Living® Plant Collection advises looking to your yard for the best fit.

“A little research about which hydrangea varieties thrive best in the unique light, soil, available space, and climate conditions of your yard (or balcony!) will empower you with the information you need to choose the right plant for the right place,” she says.

Once you’ve selected your hydrangea variety, you might be wondering what companion plants work best with this summertime stunner. To empower you to find the best fit, you might find it beneficial to be aware of traits and characteristics to avoid in companion plants. To help with that, we tapped some of the South’s foremost plant experts who shared information ranging from specific varieties to avoid to what type of growth patterns can be problematic for hydrangea varieties.

Why Are Some Plants Not Compatible With Hydrangeas?

Our list of plants you should never plant with hydrangeas is not exhaustive. There are certainly other plants out there that you’ll want to steer clear of, but knowing how to identify them is the real clincher. The most important thing to consider when determining if a certain plant is a good match for hydrangeas is growing conditions.

“Hydrangeas prefer moist, well-draining soil with a slightly acidic pH, so plants with conflicting soil preferences, such as those that require dry or alkaline soil, may not thrive alongside hydrangeas,” says Brad Addy, Greenhouse and QC Manger at  Jackson & Perkins.

Light requirements are also key. Plants that need more sunlight are unlikely to thrive alongside hydrangeas that prefer partial shade to filtered sunlight, Addy says. This could lead to problems ranging from diminished flowers to uneven growth.  

Finally, it’s important to consider your planting bed as a whole, being wary of invasive plants as well as ones with competitive root systems. “Certain plants don’t like a lot of natural competition and actually produce chemicals that can inhibit the growth of nearby plants,” says Justin Hancock, Costa Farms Horticulturalist. “Black walnut (Juglans nigra) is perhaps the most famous, but there are other trees, shrubs, and vines [to lookout for] that may try to poison your hydrangeas if they’re planted nearby.”

Plants You Should Never Plant With Hydrangeas

Black Walnut

Black walnut is an appealing choice for the shade it provides, but don’t let it fool you. “It releases a chemical into the soil around it that can inhibit your hydrangea’s growth,” warns Hancock. “If you have a black walnut, it’s best to put resistant varieties beneath or around this tree.”

Lilac

Contrary to the preferences of hydrangeas, lilac would rather alkaline soil and full sun. Planting them near hydrangeas may result in sunlight competition, soil pH imbalances, diminished growth and flowering for both plants, warns Addy.

Lavender

Lavender does best with dry soil, whereas hydrangeas prefer more moist conditions. They also differ when it comes to soil, with lavender thriving with more alkaline soil and hydrangea preferring more acidic. “Their differing growth habits and potential overcrowding may also lead to competition for resources and compromise the health and vitality of both plants,” says Addy.

Mountain Laurels

“While hydrangea macrophylla likes some shade during the heat of the day, its cousin hydrangea paniculata doesn’t,” says Hancock. “So hydrangea paniculata varieties (including the popular Vanilla Strawberry selection) aren’t good companions for plants like Mountain Laurels.”

Roses

“Roses have differing growing preferences from hydrangeas regarding soil, watering needs, growth habits, and sun requirements,” says Addy. “This disparity in sun preferences can pose challenges in providing suitable growing conditions for both plants in the same garden bed.” In addition to these challenges, the sprawling nature of roses paired with the bushy hydrangea shrubs can result in overcrowding.

Running Bamboo

Due to the invasive nature of running bamboo, it’s not a good match for hydrangeas. Its quick growth rate can squelch out nearby bloomers in a flash. If bamboo appeals to you though, Hancock says clump-forming varieties like fargesia rufa are okay.

Willow Trees

According to Vater, willow trees become highly competitive when it comes to their water supply, which can be especially problematic during the hot summer months. For that reason, avoid planting hydrangeas and willow trees nearby.