Hydrangeas, with their showy blooms and lush green foliage, are a garden favorite for many. These versatile shrubs can add a touch of elegance and vibrant color to any landscape, but understanding proper Hydrangeas Care is key to unlocking their full potential. Whether you’re a seasoned gardener or just starting out, this guide will provide you with everything you need to know to cultivate healthy, blooming hydrangeas.
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The Spruce / Claire Cohen Bates
Planting Hydrangeas for Success
The foundation of successful hydrangeas care starts with proper planting. Choosing the right time and location is crucial for establishing healthy, vigorous plants.
Timing is Key: The ideal times to plant hydrangeas are in late spring or early fall. This allows the root systems ample time to establish themselves before the stresses of extreme summer heat or winter frost. Planting during these milder seasons minimizes transplant shock and encourages robust growth in the following seasons.
Location, Location, Location: When selecting a planting spot, consider the sunlight and soil conditions. Hydrangeas thrive in locations that offer partial shade, particularly in the afternoon. Morning sun is beneficial, providing the energy they need for blooming, while afternoon shade protects them from the harshest rays which can scorch leaves and flowers, especially in hotter climates. While some hydrangeas can tolerate full sun, they will likely require more frequent watering to prevent stress.
Soil Preparation: Hydrangeas prefer fertile, humus-rich, and consistently moist, well-drained soil. Before planting, amend the soil with compost or other organic matter. This improves soil structure, drainage, and fertility, creating an optimal environment for root development and nutrient uptake. Ensure the soil is well-draining; hydrangeas do not tolerate soggy conditions, which can lead to root rot.
Planting Procedure:
- Dig the Hole: Excavate a hole that is twice as wide as the hydrangea’s root ball and just as deep. This provides plenty of space for the roots to spread out and establish.
- Position the Plant: Carefully remove the hydrangea from its nursery pot and gently loosen any circling roots. Place the root ball in the center of the hole, ensuring the top of the root ball is level with the surrounding soil surface. Planting too deeply can suffocate the roots.
- Backfill and Water: Backfill the hole with the amended soil, gently firming it around the root ball to eliminate air pockets. Water deeply immediately after planting to settle the soil and provide essential moisture to the newly planted hydrangea.
Light Requirements for Hydrangea Blooms
Understanding the light needs is vital in hydrangeas care. The amount of sunlight hydrangeas receive significantly impacts their blooming potential and overall health.
Partial Shade Preference: As mentioned, partial shade is generally ideal for most hydrangea varieties. Morning sun followed by afternoon shade offers the best of both worlds – enough sunlight for photosynthesis and bloom production, while protection from intense afternoon heat.
Full Sun Tolerance (with caveats): Some hydrangeas can tolerate full sun, especially in cooler climates. However, in hotter regions, full sun exposure can lead to stress, wilting, and scorched leaves. If you plant hydrangeas in full sun, be prepared to provide extra watering, particularly during hot and dry periods.
Too Much Shade: While hydrangeas appreciate shade, too much shade can be detrimental. Insufficient sunlight can result in reduced flower production and leggy growth. If your hydrangea is in deep shade and not blooming well, consider transplanting it to a location with more morning sun.
Soil and pH for Hydrangea Color Control
Soil plays a crucial role in hydrangeas care, not just for their overall health, but also for influencing the color of their blooms in certain varieties, particularly Hydrangea macrophylla (bigleaf hydrangeas).
Soil Type: Hydrangeas thrive in fertile, humus-rich soil. Amending your garden soil with compost, leaf mold, or well-rotted manure at planting time and annually as a top dressing will improve soil structure, drainage, and nutrient content.
Soil Moisture: Consistent moisture is essential for hydrangeas. They prefer soil that is consistently moist but not waterlogged. Well-drained soil is crucial to prevent root rot, while adequate moisture supports lush foliage and abundant blooms.
Soil pH and Flower Color: The fascinating aspect of hydrangeas is the ability to manipulate flower color in some varieties by adjusting soil pH.
- Acidic Soil (pH 6.0 and below): Acidic soil conditions promote the availability of aluminum in the soil, which is absorbed by the hydrangea and results in blue blooms. To acidify soil, you can amend it with elemental sulfur, peat moss, or use acidifying fertilizers.
- Alkaline Soil (pH 7.0 and above): In alkaline or neutral soil, aluminum is less available, leading to pink or red blooms, depending on the specific cultivar. To increase soil alkalinity, you can add lime.
- White Hydrangeas: White hydrangeas (Hydrangea arborescens, Hydrangea paniculata) are not affected by soil pH and will remain white regardless of soil acidity or alkalinity.
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The Spruce / Claire Cohen Bates
Watering Hydrangeas Effectively
Proper watering is a cornerstone of hydrangeas care. Hydrangeas are relatively thirsty plants and require consistent moisture, especially during their active growing and blooming periods.
Deep Watering: Hydrangeas benefit from deep, infrequent watering rather than frequent, shallow watering. Deep watering encourages roots to grow deeper into the soil, making the plant more drought-tolerant and resilient. Aim to water deeply one to two times per week during the growing season, depending on weather conditions.
Checking Soil Moisture: The best way to determine if your hydrangea needs water is to check the soil moisture. Stick your finger about four inches into the soil near the base of the plant. If the soil feels dry to the touch at this depth, it’s time to water.
Watering Technique: Water at the base of the plant, avoiding wetting the foliage as much as possible. Wet foliage can increase the risk of fungal diseases. Water slowly and deeply, allowing the water to soak into the soil and reach the root zone.
Adjusting Watering Schedule: Monitor weather conditions and adjust your watering schedule accordingly. Increase watering frequency during hot, dry spells and reduce watering after heavy rainfall. Potted hydrangeas will typically dry out faster than those planted in the ground and may require more frequent watering, especially during warm weather.
Wilting Leaves: Hydrangeas may wilt in very hot weather as a natural protective mechanism to reduce water loss through transpiration. This doesn’t always indicate a need for water. Observe your plant in the evening; if the leaves perk up as temperatures cool, it’s likely just heat stress and not necessarily dehydration. However, if wilting persists into the cooler evening hours, it’s a sign the plant needs water.
Temperature and Humidity Considerations
Temperature and humidity play significant roles in hydrangeas care, influencing their health and bloom quality.
Temperature Preferences: Hydrangeas thrive in moderate temperatures. They are generally hardy in USDA hardiness zones 5-9, depending on the specific species and cultivar. While they can tolerate heat, extreme heat can stress them, especially if combined with drought conditions. In regions with bitterly cold winters, some hydrangea varieties, particularly bigleaf hydrangeas (Hydrangea macrophylla), may experience bud damage or dieback if not properly protected.
Humidity Needs: Hydrangeas generally prefer moderate to high humidity levels. Dry climates can lead to issues such as brown, dry leaf edges. In dry conditions, you can increase humidity around your hydrangeas by:
- Mulching: Applying a layer of mulch around the base of the plants helps retain soil moisture and creates a more humid microclimate.
- Grouping Plants: Planting hydrangeas in groups can create a more humid environment as plants transpire moisture into the air.
- Misting (with caution): Lightly misting the foliage in the morning can temporarily increase humidity. However, avoid over-misting or misting in the evening, as this can promote fungal diseases.
Fertilizing Hydrangeas for Optimal Growth
Fertilizing is an important aspect of hydrangeas care, providing essential nutrients for healthy growth and abundant blooms. However, over-fertilizing can be detrimental, so balance is key.
Fertilizer Type: Use a balanced fertilizer with an NPK ratio of 10-10-10 or a fertilizer specifically formulated for flowering shrubs. For hydrangeas you wish to turn blue, you can use an acid-loving fertilizer.
Fertilizing Schedule: Fertilize hydrangeas in the spring as new growth emerges. Avoid fertilizing in the summer, especially after July, as this can encourage late-season growth that is susceptible to frost damage in colder climates. Over-fertilizing, particularly with high-nitrogen fertilizers, can result in lush foliage at the expense of flower production.
Soil Nutrient Level: If your soil is already rich in nutrients, you may not need to fertilize hydrangeas at all. A soil test can help determine the nutrient levels in your soil and guide your fertilization strategy.
Signs of Over-Fertilization: Be watchful for signs of over-fertilization, such as excessive leafy growth with few flowers, or brown leaf tips and edges. If you suspect over-fertilization, flush the soil thoroughly with water to leach out excess salts.
Types of Hydrangeas and Their Unique Needs
Understanding the different types of hydrangeas is crucial for tailored hydrangeas care. Hydrangeas are a diverse genus, with various species and cultivars, each with slightly different growth habits, bloom times, and pruning requirements. Two main categories are important to distinguish:
- Old Wood Bloomers: These hydrangeas, including bigleaf (mophead and lacecap), oakleaf, and mountain hydrangeas, bloom on buds formed on the previous year’s stems (old wood).
- New Wood Bloomers: These hydrangeas, such as smooth hydrangeas (Annabelle) and panicle hydrangeas (Limelight, PeeGee), bloom on buds formed on the current year’s stems (new wood).
Knowing whether your hydrangea blooms on old or new wood is critical for proper pruning, which we’ll discuss next.
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The Spruce / Adrienne Legault
Pruning Hydrangeas for Shape and Blooms
Pruning is a vital aspect of hydrangeas care, but the timing and method depend entirely on whether your hydrangea blooms on old or new wood. Improper pruning is a common reason for hydrangeas failing to bloom.
Pruning Old Wood Bloomers: For hydrangeas that bloom on old wood (bigleaf, lacecap, mophead, oakleaf, mountain), prune sparingly and at the right time.
- Timing: Prune these types immediately after they finish blooming in the summer. Avoid pruning in late summer, fall, winter, or spring, as you will be removing the flower buds for the following year.
- Method: Focus on removing dead, damaged, or crossing branches. You can also lightly shape the plant and remove a few of the oldest stems at the base to encourage new growth. Avoid heavy pruning, as this will significantly reduce or eliminate blooms for the next season.
Pruning New Wood Bloomers: For hydrangeas that bloom on new wood (smooth and panicle), pruning is more straightforward.
- Timing: Prune these types in late winter or early spring before new growth begins.
- Method: You can prune these hydrangeas more heavily. For smooth hydrangeas like ‘Annabelle’, you can cut them back almost to the ground each year. For panicle hydrangeas, you can prune back by about one-third to maintain size and shape, or prune more heavily for larger, but fewer, blooms. Pruning new wood bloomers encourages vigorous new growth and abundant flowering on the current season’s growth.
Deadheading: Deadheading, or removing spent flowers, is generally recommended for all types of hydrangeas. Deadheading improves the plant’s appearance and can encourage more blooms in some varieties by preventing seed production and redirecting energy into flower development.
Propagating Hydrangeas to Expand Your Garden
Propagating hydrangeas is a rewarding way to expand your collection or share these beautiful shrubs with friends. Hydrangeas are commonly propagated through stem cuttings or layering.
Propagation by Stem Cuttings: This is the most common and effective method for propagating hydrangeas.
- Take Cuttings: In late spring or early summer, take 6-8 inch stem cuttings from new, non-flowering growth.
- Prepare Cuttings: Remove the lower leaves, leaving only a few leaves at the top. Cut the remaining leaves in half horizontally to reduce water loss.
- Rooting Hormone (Optional): Dip the cut end of the stem in rooting hormone powder or liquid to encourage root development.
- Plant Cuttings: Insert the cuttings into pots filled with moist potting mix.
- Create Humidity: Cover the pots with plastic bags or place them in a propagator to maintain humidity.
- Rooting Time: Place the cuttings in a shaded location and keep the soil consistently moist. Roots typically develop in a few weeks.
- Transplant: Once rooted, transplant the cuttings into individual pots and grow them on until they are large enough to plant in the garden.
Propagation by Layering: This is a simpler method, particularly for beginners.
- Bend a Stem: Bend a low-growing stem to the ground, ensuring a portion of the stem makes contact with the soil.
- Secure Stem: Bury the section of stem in the soil and secure it in place with a rock or landscape pin.
- Wait for Roots: Keep the soil moist. Roots will form at the buried node over time.
- Separate and Transplant: Once roots have formed (which can take several months), carefully separate the rooted stem from the parent plant and transplant it as a new hydrangea shrub.
Potting and Repotting Hydrangeas in Containers
Hydrangeas can thrive in containers, making them ideal for patios, balconies, or smaller gardens. Choose compact varieties that grow under five feet tall for container gardening.
Container Selection: Select a large pot with drainage holes, at least 16-24 inches in diameter, to accommodate the root system. Avoid terra-cotta or unglazed ceramic pots, which can dry out quickly and may crack in freezing winter temperatures. Plastic, resin, or glazed ceramic pots are better choices.
Potting Mix: Use a high-quality potting mix amended with compost for good drainage and fertility.
Sunlight and Watering: Container hydrangeas need at least four hours of morning sun daily and frequent watering, as pots dry out more quickly than garden soil. Monitor soil moisture regularly and water thoroughly when the top inch of soil feels dry.
Repotting: Repot container hydrangeas every 3-5 years, or when they become root-bound. Choose a pot that is slightly larger than the previous one and refresh the potting mix. Repotting is best done in early spring before new growth begins.
Overwintering Hydrangeas for Cold Climates
In colder regions (zones 5 and colder), overwintering hydrangeas, especially bigleaf hydrangeas, is crucial to protect flower buds and ensure blooms the following year.
Protecting In-Ground Hydrangeas:
- Mulch Heavily: Apply a thick layer of mulch (straw, shredded leaves, pine bark) around the base of the plants in late fall to insulate the roots and crown.
- Burlap Wrap: For bigleaf hydrangeas, protect the flower buds by wrapping the shrubs in burlap. Create a burlap cage around the plant and fill it with leaves or straw for added insulation. Tie the branches gently together before wrapping.
- Avoid Late Fertilizing and Pruning: Stop fertilizing in late summer and avoid fall pruning of old-wood bloomers to prevent stimulating new growth that is vulnerable to frost damage.
Overwintering Potted Hydrangeas:
- Insulate Pots: Insulate the pots by wrapping them in burlap, bubble wrap, or moving them to an unheated garage or shed.
- Dormancy: Allow potted hydrangeas to go dormant in a cool, dark location. Water sparingly during dormancy to prevent the soil from completely drying out.
- Spring Re-emergence: In early spring, after the last frost, gradually acclimate overwintered hydrangeas back to outdoor conditions. Remove winter protection and resume regular watering and fertilization as new growth begins.
Encouraging Hydrangea Blooms and Addressing Bloom Problems
Getting hydrangeas to bloom prolifically is the ultimate goal of hydrangeas care. Here are some tips and solutions for common bloom issues:
Sunlight: Ensure your hydrangeas receive adequate sunlight – ideally morning sun and afternoon shade. Too much shade reduces blooming.
Watering: Consistent and deep watering during the growing season is essential for flower bud development. Drought stress can inhibit blooming.
Pruning (Correctly): Prune hydrangeas according to their bloom type (old wood or new wood) and timing guidelines to avoid removing flower buds.
Fertilizing (Balanced Approach): Use a balanced fertilizer in spring, avoiding high-nitrogen fertilizers that promote foliage growth over blooms. Avoid late summer fertilization.
Bloom Time and Appearance: Hydrangeas typically bloom from summer into fall, with bloom times varying by species and cultivar. Flower shapes range from mophead and lacecap to panicle and single florets. Some hydrangeas are fragrant, while others have little to no scent.
Addressing No Blooms: If your hydrangea is not blooming, consider these common reasons:
- Improper Pruning: Incorrect pruning is the most frequent cause of no blooms in old-wood blooming hydrangeas.
- Bud Damage: Late spring frosts can damage flower buds, especially on bigleaf hydrangeas.
- Too Much Shade: Insufficient sunlight reduces bloom production.
- Over-Fertilization (Nitrogen): Excessive nitrogen promotes leafy growth at the expense of flowers.
- Drought Stress: Lack of water during bud formation can inhibit blooming.
Caring for Hydrangeas After Blooming:
- Deadheading (Optional): Deadheading spent flowers improves appearance and can encourage more blooms in some varieties.
- Leave Dried Flowers for Winter Interest: Alternatively, you can leave the dried flower heads on the plant for winter interest and prune them off in early spring.
Common Hydrangea Pests and Diseases
While generally resilient, hydrangeas can be susceptible to certain pests and diseases. Regularly inspecting your plants and addressing issues promptly is part of good hydrangeas care.
Common Pests:
- Aphids: Small, soft-bodied insects that suck plant sap. Control with insecticidal soap or a strong spray of water.
- Spider Mites: Tiny mites that cause stippling on leaves. Increase humidity and use insecticidal soap or horticultural oil.
- Japanese Beetles: Metallic green beetles that skeletonize leaves and flowers. Handpick beetles or use Japanese beetle traps.
- Four-Lined Plant Bugs: Cause brown, circular spots on leaves. Remove infested foliage and use insecticidal soap if needed.
Common Diseases:
- Powdery Mildew: White powdery coating on leaves. Improve air circulation, avoid overhead watering, and use fungicides if severe.
- Botrytis Blight: Gray mold that affects flowers and leaves, especially in humid conditions. Improve air circulation, remove infected parts, and use fungicides if necessary.
- Leaf Spots: Various fungal or bacterial leaf spots can occur. Improve air circulation, avoid overhead watering, and use fungicides or bactericides if needed.
Integrated Pest Management (IPM): Employ IPM strategies for hydrangeas care, focusing on prevention, cultural controls (proper watering, air circulation), and using pesticides only as a last resort. Choose less-toxic options like insecticidal soap or horticultural oil when possible.
Common Hydrangea Problems and Solutions
Even with the best hydrangeas care, you may encounter some common problems. Here are solutions for typical issues:
No Blooms: (Addressed above) Review pruning, sunlight, watering, and fertilization.
Drooping Leaves: (Addressed above) Check soil moisture and observe if wilting recovers in the evening.
Yellowing Leaves: Yellow leaves can indicate various issues:
- Overwatering: Soggy soil can cause root rot and yellowing leaves. Improve drainage and reduce watering.
- Underwatering: Drought stress can also cause yellowing. Ensure consistent watering.
- Nutrient Deficiency: Iron deficiency (iron chlorosis) can cause yellowing between leaf veins, especially in alkaline soils. Use an acidifying fertilizer or iron supplement.
Brown Leaves, Edges, or Tips:
- Fertilizer Burn: Over-fertilization can cause salt buildup and brown leaf tips. Flush soil with water.
- Sunscald: Excessive sun exposure, especially in hot climates, can cause leaf scorch. Provide afternoon shade.
- Dry Air: Low humidity can lead to dry leaf edges. Increase humidity around the plant.
Color Loss in Blooms: Fading bloom color can be due to:
- Sun Bleaching: Intense sun can fade flower colors. Provide some afternoon shade.
- Transplant Shock: Newly transplanted hydrangeas may experience temporary color loss. Provide proper care and allow time for recovery.
- Natural Aging: Hydrangea blooms naturally fade as they age.
By understanding and addressing these common issues, you can maintain healthy and vibrant hydrangeas in your garden. Hydrangeas care, while requiring attention to detail, is ultimately rewarding, bringing years of stunning blooms and garden beauty.
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FAQ
Where should you not plant hydrangeas?
Avoid planting hydrangeas in deep shade, poorly draining soil, or locations exposed to harsh afternoon sun in hot climates.
Do hydrangeas prefer sun or shade?
Hydrangeas prefer partial shade, with morning sun and afternoon shade being ideal. Some varieties can tolerate full sun, especially in cooler climates, but may require more water.
Do hydrangeas like coffee grounds?
Coffee grounds can be beneficial for hydrangeas, particularly for varieties you want to turn blue, as they add acidity to the soil. Use coffee grounds sparingly as a soil amendment.
What happens if you cut hydrangeas to the ground?
The effect of cutting hydrangeas to the ground depends on the type. New wood bloomers (smooth and panicle hydrangeas) can be pruned to the ground in late winter or early spring and will regrow and bloom on new growth. Old wood bloomers (bigleaf, oakleaf, mountain) should not be cut to the ground, as this will remove the flower buds.
