How to Grow Bigleaf Hydrangeas for More Blooms

Bigleaf hydrangeas are some of the most loved hydrangeas in Southern yards, and it’s easy to see why. Their large green leaves, beautiful round blooms, and soft blue, pink, purple, or white flowers make them a favorite around porches, patios, foundations, and shaded garden beds.

Bigleaf hydrangeas are also known as Hydrangea macrophylla, mophead hydrangeas, lacecap hydrangeas, and sometimes French hydrangeas. They’re beautiful plants, but they can be a little picky if they’re planted in the wrong spot or pruned at the wrong time.

The good news is, once you understand what they like, bigleaf hydrangeas aren’t hard to grow.

What Are Bigleaf Hydrangeas?

Bigleaf hydrangeas are flowering shrubs known for their large leaves and colorful blooms. Most people recognize them by their big round flower heads, but some varieties have flatter lacecap-style blooms.

These hydrangeas usually bloom in late spring or summer, depending on the variety and your location. In Georgia and other Southern areas, they do best with morning sun and afternoon shade.

They don’t love baking in hot afternoon sun, especially when the heat index starts climbing. If your bigleaf hydrangea wilts during the day but perks back up in the evening, it may just be reacting to heat stress.

Best Place to Plant Bigleaf Hydrangeas

The best spot for bigleaf hydrangeas is a place that gets gentle morning sun and protection from the hot afternoon sun.

A good planting spot would be:

• Morning sun with afternoon shade
• Bright filtered light
• Moist but well-drained soil
• Protection from harsh wind
• Room for the plant to reach its mature size

Bigleaf hydrangeas can grow around 3 to 6 feet tall and wide, depending on the variety. Some stay smaller, while others get much larger over time.

Avoid planting them in dry, exposed areas where the soil gets hot and hard. These plants like steady moisture, but they don’t want to sit in soggy soil.

How Much Sun Do Bigleaf Hydrangeas Need?

Bigleaf hydrangeas need light to bloom, but too much hot sun can stress them out.

In cooler climates, they may handle more sun. But in Georgia and the South, they usually do best with:

Morning sun and afternoon shade

Too much shade can lead to fewer blooms, but too much sun can cause wilting, crispy leaves, and stressed plants.

If your hydrangea is getting full afternoon sun and struggling every summer, it may need more shade, better mulch, or deeper watering.

How to Water Bigleaf Hydrangeas

Bigleaf hydrangeas like consistent moisture. Their large leaves lose water quickly, especially during hot weather.

A deep watering a few times a week is usually better than a light sprinkle every day. You want the water to reach the root zone, not just wet the top of the soil.

During hot, dry weather, check the soil with your finger. If the top couple of inches are dry, it’s time to water.

A soaker hose or drip irrigation can help keep moisture steady without soaking the leaves.

Should You Mulch Bigleaf Hydrangeas?

Yes, mulch is one of the easiest ways to help bigleaf hydrangeas stay healthy.

Mulch helps:

• Hold moisture in the soil
• Keep roots cooler in summer
• Reduce weeds
• Protect the plant during winter
• Keep soil from drying out too quickly

Use pine bark, shredded hardwood mulch, pine straw, or composted mulch. Keep mulch a few inches away from the main stems so it doesn’t stay piled against the plant.

Why Bigleaf Hydrangea Blooms Turn Blue or Pink

One of the most interesting things about bigleaf hydrangeas is that some varieties can change bloom color based on soil conditions.

In more acidic soil, blooms may turn blue. In less acidic or more alkaline soil, blooms may turn pink. Purple often happens somewhere in between.

This color change has to do with how available aluminum is in the soil. Not every bigleaf hydrangea changes color strongly, and white varieties usually stay white.

If you want blue blooms, your soil usually needs to be more acidic. If you want pink blooms, the soil usually needs to be less acidic.

When to Prune Bigleaf Hydrangeas

This is where a lot of gardeners get into trouble.

Many bigleaf hydrangeas bloom on old wood, which means they form flower buds on stems from the previous year. If you prune them too hard in fall, winter, or early spring, you may cut off the flower buds.

The safest time to prune bigleaf hydrangeas is usually right after they finish blooming.

You can remove:

• Dead stems
• Weak or damaged growth
• Old blooms
• Crossing branches
• A few older stems to open up the plant

Try not to cut the whole plant back unless you know the variety can handle it.

Some newer bigleaf hydrangeas are reblooming types, which means they can bloom on old wood and new wood. Even then, light pruning is usually safer than heavy pruning.

Why Bigleaf Hydrangeas Don’t Bloom

If your bigleaf hydrangea looks healthy but doesn’t bloom, there are a few common reasons.

The most common causes are:

• Pruning at the wrong time
• Late spring frost damaging flower buds
• Too much shade
• Too much fertilizer
• Winter damage
• Deer eating the buds
• A variety that isn’t well suited for your area

In the South, late freezes can be a big problem. The plant may leaf out early, then a cold snap damages the flower buds before they open.

If deer are common in your yard, they can also nip off the buds before you ever see blooms.

Fertilizing Bigleaf Hydrangeas

Bigleaf hydrangeas don’t need heavy feeding. Too much fertilizer can give you lots of green leaves but fewer blooms.

A slow-release fertilizer in spring is usually enough for most plants.

Avoid fertilizing late in the season because it can encourage tender new growth before winter.

Common Bigleaf Hydrangea Problems

Bigleaf hydrangeas can have a few issues, especially in humid areas.

Common problems include:

• Leaf spot
• Powdery mildew
• Wilting from heat
• Root stress from poor drainage
• Deer damage
• Frost-damaged buds
• Brown leaf edges from too much sun or dry soil

Good spacing, morning sun, mulch, and watering at the base of the plant can help prevent many problems.

If leaves develop spots, remove badly affected leaves and avoid overhead watering when possible.

Can Bigleaf Hydrangeas Grow in Containers?

Yes, bigleaf hydrangeas can grow in containers, especially smaller varieties.

Use a large pot with drainage holes and a good-quality potting mix. Container hydrangeas dry out faster than plants in the ground, so they’ll need more attention during hot weather.

Place the pot where it gets morning sun and afternoon shade. During extreme heat, you may need to water daily.

Final Thoughts

Bigleaf hydrangeas are beautiful shrubs, but they do best when planted in the right place and pruned at the right time.

Give them morning sun, afternoon shade, steady moisture, and a good layer of mulch. Be careful with pruning, especially if you’re not sure whether your hydrangea blooms on old wood or new wood.

Once you understand what bigleaf hydrangeas need, they can reward you with some of the prettiest blooms in the yard.

At Bobby & Lynn’s Plant Farm, we’ve learned that hydrangeas don’t have to be complicated. You just have to pay attention to what the plant is telling you.