9 Benefits of Planting Hydrangeas in Fall
Hydrangeas are frost-hardy shrubs with enticing blooms. Plant them in your garden this autumn and they’ll readily acclimate to their new home. You can also plant them in the spring, but fall transplanting has clear advantages. Join seasoned grower Jerad Bryant in exploring these nine benefits of planting hydrangeas in fall.
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Every ornamental garden needs a hydrangea shrub, and fall is the best time to plant them! The Hydrangea genus is full of unique species with different flower heads, leaf shapes, and growth habits. Some hydrangeas change colors depending on their soil pH, making for a fun experiment in your home garden.
Planting these shrubs during the autumn is best for a few reasons. They enter dormancy starting in late autumn through mid-spring. Plant them as they lose their leaves and you’ll get them in the ground right as their roots accelerate their growing speed. Although nothing seems to be growing aboveground, belowground stays warm from soil insulation and fosters plant, fungal, and bacterial growth on a massive scale.
Get your favorite hydrangeas into the soil during this optimal period, and they’ll grow well the next year with little issues. You can expect fewer diseases and pests, and less weak growth from them than spring transplants. Follow the seasons, and nature will reward you for it!
However, if hard frosts arrive or the ground has layers of snow and ice, it’s too late to plant a hydrangea. It’s best to transplant your specimens four weeks or more ahead of the first frost date for your region. This gives them ample time to adapt to your garden so they overcome cold weather challenges.
Here’s more details about the nine benefits of planting hydrangeas in the fall:
Better Selection
Most gardeners think of perusing their local garden center for shrubs and trees in spring. The sun is shining, temperatures are warm, and bees buzz from flower to flower. While spring is a great time for transplanting, it’s often difficult to find your favorite plants online and in stores. The shelves are bare or full of common ornamentals no one wants to buy.
The situation is completely different during autumn! Lots of hydrangeas are available during this season as farmers pot them from their fields for retailers to sell. You’ll have a prime selection of lacecap, oakleaf, and big-leaf hydrangeas online and locally.
Oakleaf types are exceptional. They’re native to North America and have four seasons of interest. They sprout green oak-like leaves in spring, bloom white flowers in summer, their foliage turns red-orange in fall, and they have peeling brown bark visible in winter.
Here are some other common varieties that excel in North American gardens:
| Variety | Type of Hydrangea | Unique Attributes |
| ‘Miranda’ | Climbing Hydrangea | Variegated leaves with yellow margins |
| ‘Annabelle’ | Smooth Hydrangea | Giant blooms to a foot wide |
| ‘Villosa’ | Villosa Hydrangea | Blue, pink, and purple flower clusters |
| ‘Endless Summer®’ | Big-Leaf Hydrangea | Blooms on new and old wood |
| ‘Nikko Blue’ | Big-Leaf Hydrangea | Large, round, and blue flower heads |
| ‘Grandiflora’ | PeeGee Hydrangea | Ginormous, white, pyramid-shaped blooms |
| ‘Alice’ | Oakleaf Hydrangea | Rich crimson leaves in fall |
Regardless of the type you choose, you’ll want to plant your specimens as the weather cools at summer’s end. They’ll acclimate well as your garden begins to rest for the cold season.
Hardy Stems
Late spring frosts threaten sensitive hydrangea stems. These shrubs pull their energy back to the lower parts of the stems and into the roots. This technique protects the hydrangeas from extreme frosts since they have thicker wood and more insulation on their lower stems.
When you plant these shrubs during autumn, you allow them to acclimate to your garden’s weather at their preferred pace. Spring transplants have to manage late frosts, grow sprouts, and anchor their roots into the soil. Three tasks are difficult for a plant to accomplish all at once. In fall, hydrangeas only have to stabilize themselves and extend their roots.
Fall transplants that bloom on old wood, like big-leaf hydrangeas, may need more protection than new wood bloomers. Their stems contain next year’s flower buds and are susceptible to hard frosts and excessive pruning.
If temperatures drop well below freezing for longer than a day, use frost cloth over your newly planted shrub to protect it from ice and snow. Simply drape it over your shrub and weigh the ends with rocks or sticks so it’s wind-resistant.
Simple Transplanting
Fall is perfect for planting woody shrubs and trees, especially deciduous ones like hydrangeas. The ground is soft, soil microbes are active, and many plant species shift their energy from growing leaves and stems to producing roots. Fall rains bring ample moisture to your garden, so you won’t have to worry about watering your shrubs.
Plant your specimen now and it’ll acclimate with little care and maintenance. Fall rains will quench its thirst, cool temperatures will help it enter dormancy, and a lack of insect pests will ensure your shrub stays healthy this season.
Keep your plant’s soil moist but not soggy, and cover it with frost cloth before extreme freezes. Avoid fertilizing your hydrangea until spring warmth arrives and days lengthen. In zones 6 through 8, hard frosts may kill the aboveground stems. However, new shoots often emerge during spring from the plant’s base.
Strong Root Growth
As deciduous trees lose leaves and evergreens halt their growth, it may seem like nothing’s growing! We can’t see them, but roots love fall and winter. They have insulation and protection from the soil, which doesn’t freeze during winter. Areas with thick layers of mulch have extra protection to foster healthy root growth.
Snow and ice are also insulators! They protect the soil’s top layers from cold temperatures, keeping bulbs, perennials, and trees secure for the winter. Roots continue lengthening under this cover as all else stops growing aboveground.
Simply because we can’t see the roots doesn’t mean they’re not growing. Trust that they are, and place layers of compost or fall leaves near their root zone to boost them. Many trees spread their roots outwards rather than downwards, so apply your mulch well throughout the area for optimal growth come springtime.
Easy Pruning
Hydrangeas are special when it comes to their pruning processes. There are three main types: old wood bloomers, new wood bloomers, and evergreens. Most shrubs won’t require pruning after a fall transplanting, as they are already acclimating themselves to the season’s cool conditions.
You may prune dead or diseased wood off hydrangeas at any time. The only prunings you’ll want to be careful with are ones that cut into living wood. You can open up wounds that allow frost and diseases to creep into your shrub, affecting its cold hardiness.
Prune hydrangeas that bloom on old wood shortly after they finish flowering, and you’ll avoid chopping off next year’s flower clusters. Species that bloom on old growth include big-leaf, climbing, oakleaf, and mountain hydrangeas.
Prune hydrangeas that bloom on new wood anytime throughout the year. Avoid excessive shaping during winter, as this may create frosty issues for the sensitive stems. The best time to prune these bloomers is late in their dormancy from winter through early spring. Species like smooth and panicle hydrangeas prefer pruning during these seasons since they flower on new growth.
Bigger Blooms
With all that extra winter time to put down healthy roots after a fall planting, your hydrangeas will be ready to explode with new growth in the spring! They’ll suck up nutrients and water to push out new stems with leaves. These fresh leaves collect energy from sunlight to create the gorgeous blooms we love hydrangeas for.
When transplanting during the autumn you give your shrub ample time to acclimate. It’ll have weeks, if not months, to grow feeder roots in its new home. Spring transplants lack sufficient time to grow these roots and are more likely to start growing tender shoots while frosts are still frequent. This means late spring cold snaps can threaten the forming flower buds!
Fall transplants’ new shoots emerge when they should in spring, as these specimens have had ample time to adjust to your local seasons. They’ll know when to sprout and how much to grow, and they’ll have more resources than spring plantings to spread as much as they’d like.
You may selectively prune stems in the spring to further influence bloom size and frequency. Leave as many stems as possible for multiple medium-sized flower clusters. If you like giant flowers for bouquets and floral arrangements, prune some stems and leave a few alone. The remaining stems will have giant blooms as your plant gains additional energy to pump them full of nutrients.
Healthy Plants
Not only will your specimens have bodacious blooms, but they’ll also resist pests, diseases, and physiological conditions that threaten hydrangeas. Because fall plantings have more roots than their spring counterparts, they’ll have more access to fungal mycorrhizae, nutrients, and moisture.
With more access comes a high resistance to external plant pressures. If pests attack your hydrangea, it’ll have ample resources to siphon off wounds, heal openings, and push new growth to replace hurt parts. Strong, healthy plants resist infections, meaning most diseases will move past your hydrangea in search of a more suitable host.
Boost your plants further by giving them continuous applications of compost, leaf mold, or organic mulch. The thick layers foster beneficial microbes that bolster your hydrangea shrubs. Fungi, bacteria, and archaea love these materials, and they process larger molecules into smaller ones that your shrub can access readily.
Ample Time for Adjusting pH
Many varieties of big-leaf hydrangea change their flower color depending on their soil pH. They’ll typically shift blue in acidic soils and pink in alkaline ones. ‘Big Daddy’ is one such reblooming cultivar with puffball flower clusters that turn blue or pink. Others have shades of purple, white, red, and green, or a combination of these colors.
When you plant hydrangeas in the cool seasons, you have many weeks before spring warmth arrives. Add amendments during planting, and they’ll work in time for your hydrangea flowers to change colors. Before adjusting the soil pH, consider using a soil test kit to determine what level they’re at currently. Then, you can add your amendments knowing exactly how much your soil needs.
Use garden lime to raise the pH, or sweeten the soil. Apply garden sulfur to lower the pH. So long as the pH is between 5 and 6.4, your hydrangeas will grow without issues. A pH ranging between 6 to 6.4 causes pink flowers, while a pH lower than 6 causes purple or blue flowers.
Fall Leaves Aplenty
Resources are plentiful in the fall, which makes it optimal for planting and establishing hydrangeas. Find fall leaves, dead wood, and perennial stems throughout your garden as summer winds down. This is perfect for hydrangea transplanting, as fall leaves act as an insulating mulch. A thick leaf layer is like a blanket, covering and warming your sensitive hydrangea.
Use fall leaves by placing a layer four or more inches thick on your garden beds. Scatter them about so they don’t blanket the stems, but they cover the ground around the roots. Chopping leaves first before you place them helps them quickly decompose. A lawn mower is the perfect tool; simply run it over the lawn and apply the chopped mix of leaves and grass to your garden’s soil.
If you still have leaves after covering the beds, try making leaf mold or compost with them. That way you’ll have a soil-building amendment by spring to apply to your hydrangeas. Leaves are a blessing from nature—they’re free, especially useful, and crucial for the well-being of our environment. If you don’t use them, nature will!
