How to care for hydrangeas — 7 pro tips for fabulous, flowering shrubs (2024)

Learning how to care for hydrangeas is easy, so it's no wonder they're such popular plants. Of course, their huge blooms are a selling point, too, and make excellent cut flowers, both fresh and dried.

While these shrubs are low-maintenance, there are a few things to consider to keep them in their prime. Below, gardening experts reveal all the essentials — including advice on watering, soil type, and container plant care.

Whether growing in your borders or as beautiful outdoor potted plants, our pros' tips will help you enjoy a stunning hydrangea display year after year.

An expert guide on how to care for hydrangeas

A hydrangea can make an impressive addition to your whimsical garden plant ideas, and contemporary schemes alike — if looked after correctly.

1. Choose your variety carefully

When it comes to choosing hydrangeas, you're spoilt for choice. There are compact varieties perfect for pots, climbing ones that clamber up walls, and larger shrubs ideal for improving garden privacy.

Different types offer different flowers. There are those with round, snow-white flowerheads ("Annabelle", available from Nature Hills, has been popular in recent years). Some have green blooms (try Hydrangea paniculata "Little Lime®", also from Nature Hills), while others have pretty pink or brilliant blue petals.

It pays to do your research and consider your options carefully, to pick one that's the right match for your space, needs, and climate.

For instance, Diane Kuthy, the founder of How To Grow Everything, shares that she's recently planted Hydrangea aborescens "Incrediball" (available at Nature Hills) to create a large, flowering hedge. They are easy to grow and don't need any special care in order to reliably bloom in her northern climate, she highlights.

2. Plant at the optimal time

According to Anna Ohler, owner of Bright Lane Gardens nursery, you should plant hydrangeas either in the fall, or as a spring gardening job, when the weather is mild and the soil is workable. "Avoid planting during hot summer months or freezing winter conditions.

"If you live in a very hot region, planting in the fall is often a better choice to ensure your plant can receive enough water while establishing roots," she adds.

In climates with cold winters, Jessica Mercer of Plant Addicts recommends avoiding planting hydrangeas too early in the spring and risking a late frost. This could kill a newly planted hydrangea.

She says, "Similarly, in these areas, avoid planting hydrangeas close to the first expected hard freeze in late fall."

For gardeners in zone eight and above, planting can be done practically all winter, she adds, "as long as the soil is workable."

Choosing the right weather conditions and time of day for planting can also benefit your shrub. Nastya Vasylchyshyna, resident botany expert at Plantum, recommends planting in the morning, on overcast days.

"This way, you’ll avoid stressing the shrub with direct sunlight and excess heat," she says.

Growing your hydrangea as part of a container garden for a small space? The optimal planting time is the same as those destined for flower beds.

3. Provide enough space

It's always important to check your hydrangea's maturation size, as some varieties grow larger than others. For instance, Hydrangea macrophylla "Bailmer", available from Fast Growing Trees, can spread up to 6ft, while climbing hydrangeas can reach heights over 30ft.

A suitable planting space will make it easier to control in the long term, especially if you're working with a small garden. This will also improve air circulation around the plant which, Anna points out, will help prevent fungal diseases.

If growing in pots, Jessica says the container must be large enough to accommodate the dense, fibrous roots. "The medium-sized varieties will need a pot with at least a 20-inch diameter." Drainage holes are also important, she highlights. "Hydrangeas do not tolerate standing water."

4. Plant in suitable soil

If planting hydrangeas in the ground, the ideal soil is a rich, well-drained loam, Jessica says. "For sites with heavy clay or sand, work several inches of organic matter, like compost, into the soil."

If potting up, plant your hydrangea in a high-quality potting mix with plenty of organic matter and perlite for drainage, she adds. We recommend the organic perlite from Perfect Plants Nursery.

It's possible to change the flower color of varieties of Hydrangea macrophylla and Hydrangea serrata. The secret is in the pH of the soil: acidic soil will give you blue flowers, while alkaline or neutral conditions result in pink or reddish hues. You can buy suitable soil amendments online, such as Espoma's organic soil acidifier from Amazon.

"Keep in mind that using hard water can lead to the soil becoming more alkaline over time," says Nastya. Using water from a rain barrel will help keep your hydrangeas blue. Plus, it's a good way to save water — they're great for a more eco-friendly garden.

5. Get the right balance of sun and shade

Many types of hydrangeas, such as Hydrangea macrophylla and Hydrangea arborescens, are popular for shade gardens. However, Jessica warns that too much shade may result in your plant not blooming well — if at all. So, you'll need to get the balance right for the best results.

Georgia Clay of Monrovia says, "We recommend areas with morning sun and afternoon shade. If you live in a very hot area of the country, they really need a break from the heat." According to Jessica, this optimal positioning is typically on the east side of a house.

"Some varieties of Hydrangea paniculata can handle full sun," Georgia adds. "Be sure to read the tag to pick the right variety for your location."

6. Water regularly

Watering correctly is crucial for happy and healthy garden borders.

Nastya says, "Hydrangeas are water-loving plants that benefit from consistent moisture. Proper watering helps them bloom longer and more profusely, as well as keep their foliage lush and healthy.

"It’s especially important to water young plants regularly for the first few months after planting so that they can build up a robust root system," she adds.

According to Georgia, a good rule of thumb is to water your hydrangea when the first inch of the soil feels dry to the touch.

Anna says to soak the ground around the hydrangea thoroughly with each watering, ensuring there is no standing water. "If you do encounter standing water, you may need to replant the hydrangea with a better-draining soil mix. Skip watering on days that receive heavy rain."

A layer of mulch (Lowe's carry a wide selection of mulch) is a helpful addition to keep moisture in the soil on hot, sunny days, she adds.Anna also notes that hydrangeas in containers will likely need more frequent watering than those in the ground.

A large watering can, such as the Qilebi two-gallon watering can with long spout and stainless steel head from Amazon, is essential for this gardening task.

7. Fertilize in the growing season

Hydrangeas in borders can benefit from feeding during the growing season, particularly if the soil is poor or your plant is showing signs of stress.

Miracle-Gro's Performance Organics Blooms fertilizer, available from Amazon, is designed to boost flowering plants and is well-rated. Be sure to follow the application instructions on the label for best results.

Feeding is especially important for hydrangeas in planters, as the nutrients from the original potting soil will deplete over time. On this note, Anna recommends repotting container-grown hydrangeas every two to three years. Not only will this give you a chance to refresh the soil, but it will also prevent the plant from becoming root-bound.

Repotting isn't just for garden plants in containers, but it's a key part of caring for houseplants, too.

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FAQs

How do you care for hydrangeas in winter?

Hydrangeas are hardy, and those planted in the ground don't need much attention to get them winter-ready. Mulching in the fall, however, is beneficial for keeping the roots insulated and the soil moist.

Jessica recommends moving container-grown plants to a protected location over the winter, away from downspouts and areas with seasonal flooding. "You may need to wrap the pots in burlap or horticultural fabric if winter weather is severe in your area," she adds. This is a good way to protect plants from frost.

What pests and diseases can be a problem for hydrangeas?

Nastya says, "When it comes to diseases, hydrangeas are susceptible to powdery mildew and leaf spotting.You can address these fungal infections by first pruning and incinerating affected shoots and then treating the shrub with a fungicide."

An example is Bonide's Captain Jack Copper Fungicide from Amazon, with over 6,000 5-star ratings.

Garden pest control is also important when learning how to care for hydrangeas. Common interlopers include aphids, spider mites, slugs, and Japanese beetles, Jessica lists. They can rarely kill a plant, but they can leave it looking unsightly, she says.

Aphids can be knocked off your hydrangea with a strong jet of water from a garden hose, she advises. "If the infestation is large, you can spray the infected areas with insecticidal soap or neem oil."

The Garden Safe insecticidal soap from Amazon is a very popular pick and comes in a ready-to-use spray.

Spider mites prefer warm, dry conditions and tend to be drawn to drought-stressed plants, Jessica continues. "To prevent these pests, keep your hydrangea well hydrated all growing season."

You can leave beer traps for slugs, or hand-pick them from the plant (wearing gardening gloves). Japanese beetles can also be removed by hand.

Looking for more planting advice? We've got practical guides on how to grow a rose garden and tips for growing lavender, too – both of which are beautiful cottage garden plants.