How to Grow and Care for Hydrangeas

Hydrangeas are versatile and elegant perennials known for their stunning flower clusters that come in a variety of colors, including blue, pink, and white. They are relatively easy to grow, making them suitable for gardeners of all skill levels. With types ranging from Bigleaf to Panicle, hydrangeas can thrive in diverse garden settings, adding beauty and charm effortlessly.

• Common Names: Tree hydrangea, Panicle hydrangea, Peegee hydrangea
• Scientific Name: Hydrangea paniculata
• Plant Type: Shrub
• Plant Height: 8–15 ft. tall
• Growing Difficulty: Fairly easy to care for
• Bloom Time: Summer, fall
• Hardiness Zone: 4–8 (Find your hardiness zone here)
• Sunlight: Full sun to partial shade
• Soil pH: Acidic, neutral
• Watering Frequency: Water so the soil stays slightly moist

Different Methods to Grow Hydrangeas

Planting in the Ground

This method involves planting hydrangeas directly into your garden soil. It is best done in autumn or spring. Space the plants 3 to 10 feet apart, dig a hole as deep as the root ball and 2 to 3 times as wide, set the plant in the hole, half-fill with soil, water generously, then fill the rest of the hole with soil and water again.

• Pros: Suitable for long-term growth, allows for larger plants, and can be integrated into garden landscapes.
• Cons: Requires more space, initial planting can be labor-intensive, and soil conditions must be managed.

Growing from Cuttings

This method involves taking a cutting from an existing hydrangea plant. Cut a 5 to 6-inch piece from a new branch, remove the lowest pair of leaves, dust the cutting’s end with rooting hormone, plant in moistened potting mix, cover with a plastic bag, and place in a warm area sheltered from direct sunlight and wind. Water when the top layer of soil is dry.

• Pros: Cost-effective, allows for propagation of existing plants, and can be done indoors.
• Cons: Requires careful monitoring of humidity and moisture, and not all cuttings may successfully root.

Layering

This method involves burying a branch of an existing hydrangea plant to encourage it to root. In summer, dig a trench next to the plant, remove an inch of the outer bark where the branch contacts the soil, bury the bared portion, pin it with a florist’s pin or a gentle weight, and leave 6 to 12 inches of the branch tip uncovered. Water regularly. In early spring, the branch should be ready to be removed from the mother plant and transplanted.

• Pros: High success rate, minimal disturbance to the mother plant, and can be done with minimal equipment.
• Cons: Takes longer to establish new plants, and the process can be cumbersome for larger branches.

Ideal Soil and Location Requirements

Hydrangeas thrive in fertile, well-draining soils rich in organic matter. They prefer locations with morning sun and afternoon shade, especially in hotter climates. Ensuring the soil remains moist but not waterlogged is crucial for their optimal growth.

When to Plant Hydrangeas

Plant hydrangeas in autumn before the first frost or in spring after the last frost. Early morning or late afternoon is ideal to prevent wilting from heat. These seasons provide the best conditions for root establishment and growth, ensuring your hydrangeas thrive in their new environment.

Growing Hydrangeas Outdoors

The best method to grow hydrangeas outdoors is to plant them directly in the ground. This method is the easiest because hydrangeas are tolerant of various soil types and light conditions, making them versatile and low-maintenance.

1. Choose the right time. Plant hydrangeas in autumn before the first frost or in spring after the last frost.
2. Select a suitable location. Pick a spot with well-draining soil that receives full sun in the morning and some afternoon shade.
3. Prepare the soil. Enrich the soil with compost or aged manure to ensure it is fertile and well-draining.
4. Space the plants. Space hydrangeas 3 to 10 feet apart, depending on their mature size.
5. Dig the hole. Dig a hole as deep as the root ball and 2 to 3 times as wide.
6. Plant the hydrangea. Remove the hydrangea from its container, place it in the hole, half-fill with soil, water generously, then fill the rest of the hole with soil and water again.
7. Water regularly. Keep the soil slightly moist, especially during dry periods.
8. Mulch the base. Apply a layer of mulch around the base of the plant to retain moisture and improve soil texture.
9. Fertilize. Fertilize twice a year, in early spring and fall after flowers fade, to promote healthy growth and blooms.
10. Protect from wind. Ensure the plants are sheltered from strong winds to prevent stem damage.

Growing Hydrangeas Indoors

Growing hydrangeas indoors is not typically recommended due to their need for ample sunlight and space. However, if you still wish to try, here is a step-by-step guide to help you grow hydrangeas indoors.

1. Choose the right variety. Opt for smaller varieties like dwarf hydrangeas that are more suited for indoor growth.
2. Select a suitable pot. Use a pot that is at least 8 to 12 inches in diameter with drainage holes to prevent waterlogging.
3. Prepare the soil. Fill the pot with well-draining, loamy soil enriched with compost or aged manure.
4. Plant the hydrangea. Remove the hydrangea from its container, gently loosen the roots, and place it in the pot. Fill the pot with soil, ensuring the root ball is covered, and water thoroughly.
5. Place in a bright location. Position the pot where it will receive at least four hours of direct sunlight daily, preferably morning sun and afternoon shade.
6. Water regularly. Keep the soil slightly moist but not soggy. Water when the top inch of soil feels dry to the touch.
7. Maintain humidity. Hydrangeas prefer higher humidity levels. Use a humidity tray or mist the plant regularly to maintain adequate moisture in the air.
8. Fertilize. Feed the plant with a balanced, water-soluble fertilizer every two weeks during the growing season (spring and summer).
9. Prune as needed. Trim dead or yellowing leaves and spent flowers to encourage new growth and maintain the plant's shape.
10. Monitor for pests. Check regularly for common indoor pests like spider mites and aphids. Treat infestations promptly with insecticidal soap or neem oil.

Hydrangeas are not only beautiful but also fascinating in their adaptability. Did you know that the color of hydrangea flowers can change based on soil pH? Acidic soils produce blue flowers, while alkaline soils result in pink blooms. This unique trait allows gardeners to experiment with different soil treatments to achieve their desired flower color.

Caring for Hydrangeas

Watering: Hydrangeas need consistent moisture, especially during dry spells. Aim to water deeply three times a week, ensuring the soil stays slightly moist but not waterlogged. Morning watering is ideal to prevent fungal issues.

Fertilizing: While hydrangeas in rich soil may not need much fertilizer, a light application in early spring and midsummer can boost growth and blooms. Use a balanced, slow-release fertilizer or one high in phosphorus to encourage flowering.

Pest Management: Common pests like aphids, spider mites, and slugs can affect hydrangeas. A strong blast of water can dislodge aphids and mites, while organic pesticides can handle more persistent pests. Hand-picking or using slug pellets can help control slugs and snails.

Pruning: Pruning depends on the type of hydrangea. For example, panicle and smooth hydrangeas should be pruned in late winter before new growth starts. This helps maintain their shape and encourages healthy blooms.

Winter Protection: To protect hydrangeas from harsh winter conditions, cover the base with a thick layer of mulch, leaves, or straw. This insulation helps prevent root damage and keeps the plant healthy for the next growing season.

Common Challenges With Hydrangeas

Hydrangeas are generally easy to grow and quite resilient. They adapt well to various soil types and can thrive in both full sun and partial shade. Whether you're planting them in the ground or in containers, they tend to produce abundant blooms with minimal fuss. In my experience, once you get the watering routine down, these plants practically take care of themselves.

However, growing hydrangeas isn't without its challenges. Common issues include pests like aphids and spider mites, as well as diseases such as powdery mildew and root rot. Incorrect pruning and environmental stress, like late spring frost, can also affect blooming. Despite these hurdles, with a bit of care and attention, hydrangeas can be a rewarding addition to any garden.

Safety of Hydrangeas for Pets

Hydrangeas are toxic to cats, dogs, and other pets. If you suspect your pet has ingested hydrangeas, contact the ASPCA Animal Poison Control Center 24-hour hotline immediately.

Frequently Asked Questions

How do I prune hydrangeas?

Pruning hydrangeas depends on the type. For panicle and smooth hydrangeas, prune in late winter before new growth starts. For bigleaf, oakleaf, and mountain hydrangeas, prune after flowering to maintain shape and encourage healthy blooms.

Why are my hydrangeas not blooming?

Hydrangeas may not bloom due to incorrect pruning, insufficient water, improper sunlight, or wrong fertilizer. Ensure they receive morning sun and afternoon shade, and avoid pruning at the wrong time to promote blooming.

How can I change the color of my hydrangea flowers?

To change hydrangea flower color, adjust the soil pH. Acidic soils (pH below 6) produce blue flowers, while alkaline soils (pH above 7) result in pink blooms. Use soil amendments like sulfur or lime to achieve the desired pH.

What are common pests and diseases affecting hydrangeas?

Hydrangeas can be affected by pests like aphids, spider mites, and slugs, and diseases such as powdery mildew and root rot. Regular monitoring and appropriate treatments, like organic pesticides and proper watering, can help manage these issues.