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4 Important Fall Hydrangea Jobs (& One Thing You Probably Shouldn’t Do)

Hydrangeas are fun, pure and simple. What else can you say about a shrub with blooms that look like cheerleading pompoms? It’s no wonder they’re a summer mainstay in front yards everywhere.

But as the leaves on the trees begin to change color, the flowers of a hydrangea begin to fade. With the arrival of fall, you’ll need to give these showy shrubs a little post-season care to ensure you enjoy massive blossoms again next year.

Hydrangeas are easy shrubs to care for; in fact, they’re one of the easiest flowering shrubs to grow.

That being said, if you want to have shrubs that are the envy of the neighborhood, you’ll want to set aside about half an hour this fall to ensure your hydrangeas receive good care heading into the winter.

But let’s start with one hydrangea job you shouldn’t do this autumn…

1. Don’t Prune Your Hydrangeas in the Fall

Yes, you read that correctly. While you’ll often see fall pruning recommended, there’s a lot to be said for leaving them intact, blooms and all. One of the most important reasons for not pruning them in the fall is that some varieties form blooms on old wood.

These types often bloom in the early summer. Some varieties include:

  • Bigleaf Hydrangea (Hydrangea macrophylla)
  • Oakleaf Hydrangea (Hydrangea quercifolia)
  • Lacecap Hydrangea (Hydrangea macrophylla normalis)
  • Mountain Hydrangea (Hydrangea serrata)
Hydrangea serrata shouldn’t be pruned in fall

Prune these types of hydrangeas in the summer, shortly after they finish flowering. Pruning in the fall means no flowers next year.

Even if you aren’t growing “old wood blooming” varieties of hydrangeas, there’s still good reason not to prune them until late winter or early spring.

By leaving the faded paper blossoms intact, you’re creating a natural shelter that will help to protect the plant during the winter. As it snows, the dead foliage and blooms will catch the snow, creating a shelter above the crown of the plant, insulating it from the worst of the weather.  

You run the risk of opening up your plant to cold damage if you prune in the fall. Pruning stimulates new growth; this new growth is more likely to die off in cold weather, opening the plant to cold damage.

Finally, leaving the spent blossoms and old growth through the winter provides homes for pollinators and other important insects. You can prune hydrangeas in early spring once insects emerge.

4 Autumn Jobs For Happy Blooming Hydrangeas Next Spring

1. Protect From Frost

Most hydrangea species are cold, hardy, growing well in zones 3-9. If you live in a climate with harsh winters, you might want to consider wrapping your hydrangeas at the end of the season. Wrapping your shrubs in the fall will protect them from freezing temperatures and damaging winds from winter storms.

Burlap is a great choice for wrapping your hydrangeas. If you want to use what you have on hand, leaves and pine boughs are also a good option.

This hydrangea is all snug for the winter.

2. Fertilize Hydrangeas

Fall is also the time to fertilize hydrangeas. Choose a slow-release, balanced fertilizer with an NPK ratio of 10-10-10, such as this Southern Ag Slow Release Fertilizer. Apply the fertilizer, gently scratching it into the first few inches of the soil. For liquid fertilizers, water them in well.

Fertilizing in the fall provides plants with nutrients that will be stored during the plant’s dormant stage, ready to use in the spring.

If you’ve had trouble in the past trying to grow lots of blooms or larger blooms, choose a fertilizer with a much higher phosphate ratio. (That’s the middle number.) Plants need plenty of phosphorous to create flowers and fruit.

An excellent, slow-release fertilizer that’s high in phosphorous is bone meal. Add this to your soil in the fall for big, beautiful blooms next year. There are lots of great reasons to use bone meal in the garden.

3. Mulch

Hydrangeas prefer moist, well-draining soil. If you are dealing with an unseasonably dry fall, mulch is your friend. Lay down a thick layer of mulch beneath your plant to assist with holding in water.

You’ll have less watering to worry about when the rest of your plants enter their dormancy as well.

Mulch is especially important if you want weed-free hydrangeas.

Weeds can lie in wait for decades below the soil, just waiting for the right moment to pop up. Putting down a nice thick layer of mulch will help keep the soil moist and prevent weed growth.

It’s often suggested that you use pine needles or pine park to fertilize acid-loving plants due to the acid in pine. However, studies have shown that pine bark and pine needles have little effect on the acidity of the ground.

There are so many options for mulch that I’ll bet you have at least one out in your yard right now.

And finally, don’t forget this last fall hydrangea chore for colorful blooms next year.

4. Special Fall Care for Blue Hydrangeas

One of the reasons these lovely shrubs are so popular stems from their ability to change the color of their blooms depending on the acidity of the soil.

Some varieties will have shades of pink in alkaline soil. But as the pH changes, so does the color; the more acidic the soil, the more vibrant the hue. Neutral soil usually gives you lovely shades of purple, whereas acidic soil, with a pH of 6 or less, will give you the loveliest shade of blue.

However, many gardeners make the mistake of trying to acidify their soil in the spring.

The best time to adjust the pH of your soil is in the fall. Whether you use sulfur or fertilizer specifically made for acid-loving plants, such as Holly-tone, it takes time for the nutrients to break down in the soil and be readily available to your hydrangeas.

If you struggle to achieve a beautiful sky-blue hydrangea, try adding your acidic soil amendments in the fall rather than the spring. This also gives you time to test the soil periodically so you can add more if needed.

Now that your hydrangeas are taken care of, perhaps it’s time to think about getting your strawberries ready for winter.