Hydrangeas are popular flowering shrubs that produce gorgeous blooms in shades of pink, blue, purple, white and green Their lush flower heads brighten gardens and provide months of color from early summer well into fall.
But before hydrangeas burst into flower, you may notice some interesting changes in the plants’ appearance and growth habits. Learning what hydrangeas look like before blooming can help you anticipate when these showy shrubs will finally flower.
The Bud Stage
The most obvious sign that hydrangeas are getting ready to bloom is the emergence of flower buds on the plants. These swollen bumps along the stems are easy to spot and indicate blooms are coming soon.
On old wood varieties like bigleaf oakleaf and climbing hydrangeas, plump flower buds form at the tips of stems in late summer and fall the year before the plant flowers. The buds remain dormant through winter, then begin swelling and opening when temperatures warm in spring.
You’ll see the gray-green buds sprouting like broccoli heads on old stems. They continue enlarging over several weeks before the flowers emerge. Old wood hydrangeas generally bloom from May through July.
New wood hydrangeas like panicle and smooth hydrangeas produce their flower buds in spring on new shoots growing the same season These green or purplish buds are scattered along the length of fresh, supple stems and bloom a bit later, usually from June to September.
Leaf Growth
As buds swell, you’ll notice the leaves rapidly unfurling too. Hydrangeas produce lush, bright green foliage that precedes and accompanies the blooms.
The fresh leaves emerge from buds at the tips of stems early in spring on old wood varieties. New wood types grow new leaves and stems simultaneously a bit later in spring. The burgeoning foliage provides energy to support the pending blooms.
Leaves continue expanding and reach full size right before or as hydrangea flowers open. Healthy, vibrant leaves support larger, more prolific blooms, so this exuberant foliage growth is a great sign flowers are imminent.
Changing Branch Flexibility
The stems and branches also go through changes before hydrangea flowers appear. On old wood plants, last year’s mature woody stems bear the flower buds through winter then eventually the blossoms.
These aging branches are thick, stiff, and brittle. But the emerging flower buds make the tips more pliable and flexible again for a short period.
On new wood hydrangeas, the fresh shoots growing from old stems are supple, green, and flexible when they first emerge. They remain so as flower buds form on the new growth through late spring.
The brief return of flexibility signals the stems are reviving before flowers bloom. Once hydrangeas finish flowering, the stems will toughen and harden again.
Coloring Up
Some varieties like bigleaf and oakleaf hydrangeas change color before their flowers open. The emerging foliage often turns bronze, burgundy, or purplish during the bud stage.
This temporary coloring results from pigments called anthocyanins that protect the tender new growth. Red or purple tinged leaves indicate flowers are getting ready to form. Leaves will fade back to green once they mature.
Panicle and smooth hydrangeas leaves can sometimes take on red hues in fall when temperatures drop. But spring coloring is more common on types that bloom early on old wood.
Flowering Timeframes
Knowing when various hydrangea types normally bloom can also help you determine if those swelling buds will open soon. Here are the general flowering months for common hydrangeas:
- Bigleaf – June to July
- Oakleaf – May to July
- Climbing – June to July
- Mountain – May to August
- Panicle – June to September
- Smooth – June to September
Tracking your individual plants’ bloom schedule each year will help refine when you can expect flowers. But these months provide a general guide for anticipating hydrangea flowers based on variety.
Preparing for Blooms
Once you spot plump buds, more flexible stems, colorful foliage, and ample leaf growth, hydrangea blooms are only weeks away! Here are some tips to prep your plants and maximize flowering:
- Give plants a bloom-boosting fertilizer in early spring as growth starts.
- Prune old wood hydrangeas immediately after flowering to avoid removing next year’s buds.
- Water thoroughly during bud stage to hydrate swelling growth.
- Provide partial shade in hot climates to prevent wilting.
- Add mulch around the base to maintain soil moisture and temperature.
- Stake floppy stems of top-heavy bloomers like panicle hydrangeas.
With proper care, your hydrangeas will transition gracefully from the bud stage to produce their vibrant blossoms on schedule. Paying attention to the subtler changes before blooms emerge allows you to support this growth and enjoy even more flowers.
Frequently Asked Questions
What causes hydrangeas not to flower?
Hydrangeas may fail to bloom if they didn’t form flower buds the previous season due to late pruning, improper care, or weather damage. Insufficient sunlight, over-pruning, excessive nitrogen fertilizer, and unsuitable growing conditions can also prevent flowering.
When should you cut back hydrangeas for winter?
Old wood hydrangeas that bloom on last year’s growth should only be pruned after flowering in summer to avoid removing next year’s buds. New wood types that bloom on current season’s growth can be pruned in late fall, winter, or very early spring before new growth begins.
Do hydrangeas bloom every year?
Most hydrangeas will bloom annually with proper care. Old wood varieties produce flower buds that overwinter while new wood types grow new shoots that develop blooms each growing season. Providing suitable conditions for the specific hydrangea types you grow will promote yearly flowering.
How can you tell if hydrangea buds are dead?
Dead hydrangea buds will be dried out, brown or blackened, and shriveled rather than plump and swollen. Damaged winter buds often fall off the plant once growth resumes in spring. Minimal leaf growth around the buds is another sign of winterkill.
Do hydrangeas change color before blooming?
Some varieties like bigleaf and oakleaf hydrangeas can develop red, burgundy, or purple foliage as their buds begin to swell and open. This temporary color change is caused by pigments in the new growth that protect emerging tissue. Leaves fade back to green once mature.
Final Thoughts
The stages leading up to hydrangea flowers provide clues the spectacular blooms are on their way. Watch for plumping buds, leaf growth, stem flexibility, and even foliage color changes to tell if your hydrangeas will soon flower. Anticipating this transition allows you to provide extra care to maximize their blossoms.
With the right growing conditions and preparation based on their bud development, your beloved hydrangeas will flourish and enhance your garden with their signature flowers summer through fall. Paying attention to their progress as blooming approaches is time well spent to enjoy these charming shrubs at their colorful peak.
Add the Right Amount of Sun
Many of us underestimate a hydrangea’s need for sun. About half a day is a suitable target, ideally in the morning. But if you only have a place with the afternoon sun, that’s OK. Except if you garden in southern states. Southern gardeners need to avoid that scorching afternoon sun. It doesn’t matter where you put your plant; you should always make sure they don’t cook.
Watch The Fertilizer during your Hydrangea Check Up
With fertilizer, more is not better. The first number on the package tells you how much nitrogen to give your hydrangeas. If you do, you’ll get a beautiful green bush with few flowers. Shrub, rose, or flower food that is organic or time-release will give the plant the right balance of nutrients that it can use as it grows.