Hydrangeas are a beautiful and popular flowering shrub that can add color and elegance to your garden. However, pruning hydrangeas can be a bit tricky, especially for beginners. If you prune them incorrectly, you could damage the plant or prevent it from blooming.
To help you avoid these mistakes, here are some hydrangea pruning tips for beginners:
1. Know Your Hydrangea Type
There are two main types of hydrangeas: bigleaf hydrangeas (Hydrangea macrophylla) and panicle hydrangeas (Hydrangea paniculata). Bigleaf hydrangeas bloom on old wood, while panicle hydrangeas bloom on new wood. This means that you need to prune bigleaf hydrangeas differently than panicle hydrangeas.
2. Prune Bigleaf Hydrangeas in Late Winter or Early Spring
Bigleaf hydrangeas should be pruned in late winter or early spring, before new growth begins. To prune a bigleaf hydrangea, simply remove any dead or damaged stems. You can also remove any stems that are crossing or rubbing against each other.
3. Prune Panicle Hydrangeas in Fall or Winter
Panicle hydrangeas can be pruned in fall or winter, after the leaves have fallen. To prune a panicle hydrangea, simply remove any dead or damaged stems. You can also remove any stems that are crossing or rubbing against each other.
4. Remove Spent Blooms
After your hydrangeas have finished blooming, you can remove the spent blooms. This will help to encourage new growth and flowering the following year.
5. Don’t Prune Too Hard
When pruning hydrangeas, it is important not to prune too hard. Pruning too hard can damage the plant and prevent it from blooming.
Here is a table summarizing the pruning tips for bigleaf and panicle hydrangeas:
Hydrangea Type | Pruning Time | How to Prune |
---|---|---|
Bigleaf Hydrangeas | Late winter or early spring | Remove dead or damaged stems, and stems that are crossing or rubbing against each other. |
Panicle Hydrangeas | Fall or winter | Remove dead or damaged stems, and stems that are crossing or rubbing against each other. |
Frequently Asked Questions (FAQ)
Q: Can I prune hydrangeas in the summer?
A: It is not recommended to prune hydrangeas in the summer, as this can prevent them from blooming the following year.
Q: How do I know if my hydrangea is a bigleaf hydrangea or a panicle hydrangea?
A: Bigleaf hydrangeas have large, showy flowers that can be blue, pink, or purple. Panicle hydrangeas have smaller, cone-shaped flowers that are usually white or pink.
Q: What is the best time to plant hydrangeas?
A: The best time to plant hydrangeas is in the spring or fall, when the weather is cool and the soil is moist.
References:
How to Prune Hydrangeas for Big Blooms
Prune hydrangeas in late winter or early spring, before new growth emerges. Remove dead, diseased, or weak stems.
For mophead and lacecap hydrangeas that bloom on old wood:
- Cut back previous year’s stems by one-third to one-half their length.
- Avoid cutting into new growth, as this will reduce blooming potential.
For panicle and climbing hydrangeas that bloom on new wood:
- Cut back stems by two-thirds to three-quarters their length.
- Remove any weak or spindly stems.
- Prune periodically throughout the growing season to encourage bushy growth and larger panicles.
Hydrangea Pruning Techniques for Different Varieties
Bigleaf Hydrangeas (Hydrangea macrophylla):
- Prune after flowering, late winter to early spring.
- Cut back shoots to 12-18 inches above the ground.
- Remove dead, diseased, or crossing branches.
Panicle Hydrangeas (Hydrangea paniculata):
- Prune in late winter or early spring.
- Cut back stems to 2-4 buds above the previous year’s growth.
- Remove weak or thin branches.
Smooth Hydrangeas (Hydrangea arborescens):
- Prune in late winter or early spring.
- Cut back stems to the ground to promote vigorous new growth.
- Remove dead or diseased canes.
Climbing Hydrangeas (Hydrangea anomala petiolaris):
- Prune after flowering, removing only dead or damaged branches.
- Do not prune foliage, as it adds aesthetic interest during winter.
Oakleaf Hydrangeas (Hydrangea quercifolia):
- Prune in winter or early spring.
- Remove any branches that are crossing or rubbing together.
- Shape the plant as desired, but avoid removing too much foliage as it reduces flower production.
Best Time to Prune Hydrangeas
Prune hydrangeas at the right time to encourage healthy growth and optimal blooms:
- Summer-Blooming Hydrangeas (Macrophylla, paniculata, arborescens):
- Prune after flowering (late summer or early fall) to avoid removing next year’s flower buds.
- Spring-Blooming Hydrangeas (quercifolia, serrata):
- Prune in late winter or early spring, before buds appear, to encourage new stem growth.
- Reblooming Hydrangeas (Endless Summer, Bloomstruck):
- Prune once in late winter or early spring, removing dead or weak canes, and again after the first bloom cycle (before July 15) to promote reblooming.
Spring Pruning of Hydrangeas
Step 1: Determine Hydrangea Type
- Identify the type of hydrangea you have, as different types require different pruning techniques.
Step 2: Remove Dead or Diseased Stems
- Cut off any dead, broken, or diseased stems at the base.
Step 3: Prune Spent Flower Heads
- For varieties that bloom on old wood (e.g., mopheads, lacecaps), remove spent flower heads by cutting just above the first pair of healthy leaves below the flower.
Step 4: Rejuvenate Old Hydrangeas
- For hydrangeas that have become overgrown or unproductive, prune back severely by cutting stems to 18-24 inches above the ground.
Step 5: Shape and Thin
- Remove any weak or crossing branches.
- Thin out dense growth to allow sunlight and air circulation.
Step 6: Fertilize
- After pruning, fertilize hydrangeas with a balanced fertilizer to promote healthy growth and flowering.
How to Prune Hydrangeas in the Fall
Steps:
- Identify Type of Hydrangea: Determine the type of hydrangea (old wood vs. new wood bloomers) to ascertain proper timing.
- Time of Pruning: Prune old wood bloomers (e.g., bigleaf and mountain) in late fall or early winter, after flowering. New wood bloomers (e.g., paniculata and arborescens) should be pruned in early spring.
- Remove Old Canes: Use sharp shears to cut back old canes (typically brown or gray) to the ground.
- Thin Canes: Thin out crowded or crossing canes, leaving 3-5 strong canes per plant.
- Trim Side Shoots: Cut back side shoots on remaining canes to 2-3 buds.
- Clean Up Debris: Remove all pruned canes and debris from around the plant.
Hydrangea Pruning for Cold Climates
In cold climates, hydrangeas require specific pruning techniques to ensure optimal growth and flowering. Here’s a summary:
Prune Macrophyllas (Bigleaf):
- Prune in fall or early spring before new growth begins.
- Remove old, dead, or diseased stems.
- Cut back stems that flowered the previous year to a pair of healthy buds near the base.
- Avoid cutting into new growth, as this can remove potential flower buds.
Prune Paniculatas (PeeGee):
- Prune in late winter or early spring before buds break.
- Cut back stems to 12-18 inches above the ground.
- Thin out congested branches to promote airflow and prevent disease.
Prune Arborascens (Smooth):
- Prune in late winter or early spring before new growth begins.
- Remove old, dead, or weak stems.
- Cut back main stems by one-third to encourage bushy growth.
General Tips:
- Use sharp, clean pruning shears.
- Make clean, angled cuts to reduce the risk of disease.
- Remove any suckers that may sprout from the base of the plant.
- Apply a balanced fertilizer after pruning to support new growth.
Hydrangea Pruning for Warm Climates
Hydrangeas bloom on old and new wood in warm climates, so pruning time depends on the desired bloom time.
- For early blooms on old wood: Prune lightly after flowering, removing only spent blooms and dead branches.
- For blooms on new wood: Prune severely in late winter or early spring, cutting stems back to 1-2 nodes from the base.
- For continuous blooms: Prune half of the plant lightly after flowering and half severely in late winter or early spring.
- Avoid drastic pruning: This can weaken the plant and reduce flowering.
- Use clean, sharp pruners: To prevent disease spread and promote clean cuts.
Pruning Overgrown Hydrangeas
When hydrangeas become overgrown and unmanageable, pruning can rejuvenate and revitalize them. Here are key steps to follow for effective pruning:
- Determine hydrangea type: Different hydrangea varieties bloom on different types of wood (old or new). Identify your variety to ensure accurate pruning.
- Prune in late winter or early spring: Before new growth emerges, remove dead, diseased, or weak stems.
- Remove old stems: Cut out stems that are thick, woody, and have no flower buds.
- Thin stems: Select the strongest stems and remove any thin, spindly ones that compete for space.
- Shape the plant: Prune branches to create a desired shape, such as a round or pyramidal form.
- Fertilize after pruning: Amend the soil with a balanced fertilizer to encourage new growth and flowering.
- Water regularly: Water your hydrangea deeply after pruning to prevent stress and promote recovery.
- Be patient: Pruning overgrown hydrangeas may take several seasons to achieve the desired results.
Pruning Hydrangeas for Winter Protection
To prepare hydrangeas for winter, proper pruning is essential. Follow these steps to protect your plants from harsh winter conditions:
1. Choose the Correct Pruning Time:
Prune hydrangeas in late fall or early winter, after the first hard frost.
2. Identify Dead or Weak Canes:
Remove any dead, diseased, or weak canes. These canes are susceptible to damage during winter.
3. Cut Back Old Bloom Heads:
Remove the faded bloom heads from the previous season. Cutting them back to the first set of healthy buds encourages new growth.
4. Reduce the Height:
For Annabelle hydrangeas (Hydrangea arborescens), cut them back to 6-12 inches above the ground. For other varieties, reduce the height by about one-third.
5. Remove Crossing or Interfering Branches:
Trim any branches that cross or interfere with each other. This promotes better air circulation and reduces the risk of breakage.
6. Avoid Pruning Too Severely:
Do not prune hydrangeas too severely, as this can reduce flowering.
7. Protect the Cut Ends:
Apply a pruning sealant or wax to the cut ends of the canes to prevent moisture loss and disease.
By following these steps, you can effectively prune your hydrangeas and prepare them for winter protection, ensuring their health and beauty come spring.
Pruning Hydrangeas for Reblooming
To ensure continuous blooms, prune hydrangeas at the right time and follow these steps:
- Time of Pruning: Prune once clusters fade, typically in late summer or early fall.
- Identification: Determine the type of hydrangea as different types have specific pruning requirements.
- Removal of Spent Blooms: Cut off dead or faded flower heads just above the first or second set of leaves. This encourages new growth and promotes reblooming.
- Old Wood Removal: Remove any dead, diseased, or weak stems at the base of the plant to prevent disease and improve airflow.
- Stem Pruning: For mophead and lacecap hydrangeas, cut back old stems to a healthy bud pair. For paniculata hydrangeas, prune stems to the desired length or height.
- General Rule: Do not prune more than one-third of the plant at a time to avoid over-pruning and reduce reblooming potential.
Pruning Hydrangeas for Specific Bloom Colors
Hydrangeas are popular flowering shrubs that bloom in a range of colors from blue to pink, purple, and white. The color of hydrangea blooms is determined by the pH level of the soil in which they are grown. To control the bloom color, it is important to prune hydrangeas correctly.
- Blue hydrangeas: To promote blue blooms, hydrangeas should be pruned in late winter or early spring before new growth begins. This pruning will remove old, woody stems that have flowered the previous year. New growth will then emerge and produce blue blooms on new stems.
- Pink hydrangeas: To encourage pink blooms, hydrangeas should be pruned in late summer after they have finished blooming. This pruning will remove spent blooms and promote new growth that will produce pink flowers the following year.
- Purple hydrangeas: Purple hydrangeas are a hybrid of blue and pink hydrangeas. To achieve purple blooms, hydrangeas should be pruned in late winter or early spring to promote new growth. The pH level of the soil should also be adjusted to a slightly acidic level (pH 5.5-6.5) to encourage purple blooms.
- White hydrangeas: White hydrangeas do not change color with the pH level of the soil. They should be pruned in late winter or early spring to promote new growth and flowering.