This post may contain affiliate links.
Hydrangeas, with their big, colorful blooms and lush foliage, add beauty and structure to a garden. They’re fairly easy to grow too—thriving in moist, well-drained soil that’s rich in nutrients.
While hydrangeas generally get along well with a variety of plants, not every plant is a good fit. Some plants compete for water, nutrients, or space, stressing your hydrangeas and stunting their growth. To help your hydrangeas truly thrive, it’s worth knowing which plants to keep at a distance.
Below are 14 plants you’ll want to avoid planting too close to your hydrangeas.
Dwarf Bearded Irises
Dwarf irises enjoy the sun to partial shade and well-drained soil, but do not fare well in the dense shade or moist soil that hydrangeas may create. While tough, their preference for drier conditions makes them poor companions for hydrangeas, which can lead to water competition.
Tender Geraniums
Tender geraniums are well-suited to hot, sunny, and dry conditions, quite the opposite of what hydrangeas require. While they can make visually appealing neighbors, the fundamental differences in their growing conditions mean they should not share the same garden space.
Black Walnut Tree
Black walnut trees produce juglone, a substance toxic to many plants, including hydrangeas. This chemical inhibits the growth of hydrangeas and other sensitive plants nearby. Additionally, the extensive root system and large canopy of black walnuts create competitive conditions unfavorable for hydrangeas.
Sunflower
Sunflowers thrive in full sun and hotter conditions, making them quite different in their needs compared to hydrangeas. The stark contrast in their requirements can lead to competitive growth if planted too close together. It’s best to plant sunflowers in a separate area where they can enjoy the full sunlight without affecting the growth of hydrangeas.
Lilac Bush
Lilac bushes prefer full sun and alkaline soil, contrasting sharply with the acidic soil and partial shade that hydrangeas need. While both are beautiful, lilacs and hydrangeas will compete for moisture and space, and the soil pH necessary for lilacs can hinder hydrangea health.
Rosemary
Rosemary is a perennial herb that flourishes in sunny, dry environments and prefers lean, well-draining soil. This makes it a poor match for hydrangeas, which thrive in moist, slightly acidic soil and benefit from some shade.
Because rosemary and hydrangeas have such different needs for sunlight and soil, planting them close together can lead to problems. Rosemary may dominate the available resources, depriving hydrangeas of the moisture and nutrients they need to thrive.
Peppers
Peppers are another high-sun, low-water plant that conflicts with the needs of hydrangeas. While peppers do well in containers that can be managed separately, planting them in the ground alongside hydrangeas can result in competition for water and nutrients, with peppers likely dominating the relationship.
China Aster
China
Amur Maple
While smaller than many trees, the amur maple still competes intensely with hydrangeas for root space and nutrients. Despite its tolerance for partial shade, its root competition and preference for well-draining soil can stress nearby hydrangea plants, making close planting inadvisable.
Squash
Squash plants, including zucchini, are vigorous growers and heavy feeders that require a lot of space and nutrients, which can deprive hydrangeas of essential resources. Their differing needs for mulching and full sun make them incompatible with hydrangeas in a shared garden space.
Oak Tree
Oak trees create a challenging environment for hydrangeas due to their large size and dense canopy. This can limit sunlight and space for hydrangeas, and their extensive root systems compete heavily with those of hydrangeas for water and nutrients. Planting hydrangeas too close to oak trees can severely inhibit their growth.
Lavender
Lavender and hydrangeas are fundamentally mismatched in a garden setting. Lavender loves full sun and dry, alkaline soil, whereas hydrangeas flourish in moist, slightly acidic conditions.
Asparagus
Asparagus and hydrangeas have conflicting soil pH preferences, making co-planting them problematic. Asparagus thrives in alkaline soil, while hydrangeas prefer acidic conditions. Keeping these plants separate helps avoid compromising their soil needs and ensures better growth and health.
Sedum Burrito
Sedum burrito is a succulent that thrives in dry, sunny locations. Its need for minimal water and high light does not complement the moist, semi-shaded environment preferred by hydrangeas, making them unsuitable garden friends.
12 Plants to Grow Alongside Your Blueberry Bushes to Keep Them Happy
Planting the right companion plants near blueberry bushes can help to ensure successful fruiting. Here are some plants that you should grow alongside blueberry bushes to help them thrive.
12 Plants to Grow Alongside Your Blueberry Bushes to Keep Them Happy
28 Budget-Friendly Front Yard Ideas for Stunning Curb Appeal
Improving your home’s curb appeal not only presents well but can also boost your home’s value. Here are 28 to give your front yard the attention it deserves and transform it into a beautiful and inviting space you can be proud of.
28 Budget-Friendly Front Yard Ideas for Stunning Curb Appeal
30 Native Plants That Will Draw Beautiful Birds to Your Yard
If you want to attract more birds to your garden, the right plant choices can make all the difference. Here are 16 native plants that will attract a variety of birds.
30 Native Plants That Will Draw Beautiful Birds to Your Yard
