I have three types of hydrangeas in my garden.

I have panicle hydrangeas, Vanilla Strawberry by First Editions, Quick Fire Fab, and Bobo Hydrangeas by Proven Winners

I have bigleaf hydrangea, Big Daddy by Southern Living Plant Collection.

Lastly, I have an oakleaf hydrangea, Ruby Slippers.

There is no shortage of information about the beautiful flowers, foliage and stems of hydrangeas, but it is harder to find examples of their condition when not in season.

This is particularly important when growing hydrangeas in the south because we have a longer (in terms to temperature) fall, well outside of the typical growing season for hydrangeas.

I am sharing how hydrangeas perform after first frost but before consistent winter temperature which most likely will not happen for another 6-8 weeks in the south.

Knowing how they perform during the fall, after first frost, can help you decide on which type to purchase or better yet, where you really should be placing them in your garden if you are in the south.

First, these are things that are really important to know before you buy a particular type of hydrangea.

What are Panicle Hydrangeas (Hydrangea paniculate)?

Panicle hydrangeas are a popular and versatile shrub.

These deciduous plants are known for their large, cone-shaped blooms that can range in color from white to shades of pink and even red.

Panicle hydrangeas are generally hardy and adaptable, thriving in a variety of soil conditions and climates.

They typically bloom in the summer and can be pruned to control their size and shape.

Typical summer temperatures for the North actually begin in April/May for us in the South, so while the month would suggest it is Spring, the hydrangeas are beginning to experiencing summer.

If nothing else sticks in your mind, know that panicle hydrangeas bloom on new wood.

This means you can cut back branches on panicle hydrangea any time after the shrub has gone completely dormant.

This is contrast to the typical recommendation of pruning late winter/early spring because your climate should dictate the maintenance of your hydrangea shrub.

Gardeners who experience heavy snow during the winter prefer to prune their panicle hydrangeas before the first heavy snowfall.

They find that this prevents branches from breaking irregularly from the weight of the snow and they have more control over the shrub’s shape going into the next growing season.

What are Bigleaf Hydrangeas (Hydrangea macrophylla)?

Bigleaf hydrangeas, or Hydrangea macrophylla, are recognized by for their distinctive oversized, serrated foliage and globe-shaped flowers.

Bigleaf hydrangeas typically bloom in the summer and their globe-shaped blooms can change color based on soil pH, shifting from blue in acidic soils to pink in alkaline conditions.

If nothing else sticks in your mind, know that bigleaf hydrangeas bloom on old wood.

This means the buds that will become blooms next growing season are on the branches that formed this year.

Some newer varieties of bigleaf hydrangea have been developed to bloom on both new and old wood.

However, as a new gardener, you should still treat these as if they only bloom on old wood until you get used to the specific plant.

A popular search question about bigleaf hydrangeas is “Why are my hydrangeas not blooming?”

The three biggest culprits for why your bigleaf hydrangea is not blooming are:

1. It is tricky for new gardeners to time pruning bigleaf hydrangeas
2. Newly planted shrubs spend the first true growing season in your garden establishing roots instead of producing tons of flowers
3. A harsh winter or unsuspecting late freeze can damage buds that were set to bloom the following season

What are Oakleaf Hydrangeas (Hydrangea quercifolia)?

Oakleaf hydrangeas, or Hydrangea quercifolia, have distinctive oak-shaped leaves that turn interesting shades of red, orange, and purple in the fall.

More specifically, the leaves of an oakleaf hydrangea are reminiscent of a black oak or shumard oak leaf if they were oversized.

They produce elongated, cone-shaped blooms in the summer, which initially appear white but can transition to pink as they age.

What sets oakleaf hydrangeas apart from other hydrangeas is their unique peeling bark.

If nothing else sticks in your mind, know that oakleaf hydrangeas bloom on old wood.

What happens to hydrangeas after first frost?

Before we talk about what happens to hydrangeas after first frost, I would be remise if I did not mention that in the south, all hydrangea blooms in full afternoon sun are burnt to crisp by September. 

 

Now that we got that out of the way…

 

From beginning of fall to first frost, panicle hydrangeas will drop some of their leaves.

However, if you live in Zone 7B, North Alabama like I do (or warmer), panicle hydrangeas may not drop all their leaves until consistent winter weather temperatures or if they are protected from the afternoon sun and well watered.

If you have any leaves left on your panicle hydrangea when first frost arrives, you will find that the leaves are still quite hardy, with minimal wilt.

Bigleaf hydrangeas and oakleaf hydrangeas keep their leaves longer than panicle hydrangeas.

However, the hardiness of their leaves after first frost could not be more different.

Bigleaf hydrangea leaves are the saddest of the bunch in my garden because their leaves darken to a muddy green and wilt.

Oakleaf hydrangea leaves are unbothered by the first frost and continue to turn beautiful fall shades of red, orange, and purple.

 

What to do after first frost?

The simple answer is do nothing.

Hydrangeas rated for your planting zone will survive, despite the weather’s best efforts.

However, southern gardeners are in a unique position to have a longer out-of-season period after the first frost.

So if you want to be proactive, there is one thing you can do.

Mulch the base of your plant to protect the roots.

While we get to enjoy fall weather long after first frost, there are still dramatic and eractic swings in temperature that plants need protection from.

The fallen (and disease-free) leaves in your yard are great as mulch and it is free!

 

How I view hydrangeas going forward

I valued knowing how hydrangeas perform during the fall, after first frost.

It is helpful in deciding which type to purchase or where they are best suited in the garden.

Starting with my experience with panicle hydrangeas: I still think they are a great plant that I will continue to purchase.

However, in my Zone 7B North Alabama, the blooms on panicle hydrangeas are burnt to a crisp from our hot summer and begin to lose their leaves early to mid-fall.

This means by the fall, I no longer get the golden dried blooms supported by the stately branch structure I was used to when I gardened in Northeast, Zone 6B Pennsylvania.

When I purchase more, I will plant them in a spot that gets morning sun and afternoon shade to protect them better.

With bigleaf hydrangeas, I will not plant them as a focal point or feature plant in the future

I think they are best suited for a woodland garden bed with mixed shrubs and perennials to distract from the unpleasant wilted leaves after first frost.

I currently have it as a feature plant in an arborvitae and hydrangea hedge, and I just have to live with it.

Lastly, I will be purchasing more oakleaf hydrangeas in the future.

After 3 days in a row of below 30-degree nights, the Ruby Slippers did not skip a beat!

Not only do oakleaf hydrangeas hold on to their leaves, their hardiness has allowed me to enjoy the shades of red, orange, and purple foliage in the fall.

For the southern gardener, oakleaf hydrangeas are truly great as a feature plant, hedge plant, or tucked in a woodland garden bed.