How to Care for Hydrangeas: Planting, Pruning, and Soil Tips

Hydrangeas are versatile, stunning shrubs that can transform any garden with lush, colourful blooms. Whether you’re drawn to their dramatic, large flower heads or their ability to adapt to various garden conditions, hydrangea plants add beauty and charm to outdoor spaces. With a wide range of varieties available, there’s a perfect hydrangea for every gardener. This guide will walk you through all the essential steps to care for your hydrangeas: planting, pruning, fertilising, soil pH management, and more, so you can easily grow healthy, thriving plants.

Which Hydrangea Varieties Are Right for Your Garden?

Hydrangeas offer many stunning options to suit gardens of all styles and sizes. Hydrangea paniculata, for example, is known for its conical flower heads and tolerance of sunnier locations. This variety blooms on new wood, allowing you to prune heavily in winter or early spring without impacting flowering.

Hydrangea macrophylla is another favourite, and it is available in two main types: mopheads and lace caps. Mopheads are loved for their large, spherical flowers, while lacecaps offer a more delicate arrangement of flat blooms. If you want something unique, hydrangea quercifolia (oak-leaved hydrangea) stands out with its bold, textured foliage and stunning autumn colours.

Compact hydrangea options, such as hydrangea ‘Tabletop’ or hydrangea ‘Jetstream,’ are perfect for patios or smaller gardens. If you need vertical interest, climbing hydrangeas can transform walls and fences with vibrant green foliage and white flowers.

How to Plant Hydrangea Shrubs for Success

Planting hydrangeas in the correct location is key to their success. Most varieties prefer partial shade, although hydrangea paniculata can tolerate more direct sun. Choose a spot that offers shelter from harsh winds and avoids intense afternoon heat.

Please prepare the soil by ensuring it is well-draining yet retains enough moisture to support the shrubs. Hydrangeas thrive in slightly acidic soil, with a pH range of 5.5 to 6.5. Before planting, it’s a good idea to check your soil’s pH with a simple soil testing kit—these are widely available and easy to use. The results will help you determine whether amendments are needed. Mixing in ericaceous compost can help create the perfect conditions, particularly for blue-flowering varieties requiring more acidic soil to maintain their colour. Dig a hole as deep as the plant’s root ball and set the shrub to level the crown with the soil surface. Water well after planting to encourage healthy establishment.

How Does Soil Acidity Affect Hydrangea Colour?

A standout feature of hydrangea macrophylla varieties is their ability to change flower colour based on soil acidity. Blue flowers result from acidic soil, typically with a pH below 6. Alkaline soil, on the other hand, produces pink flowers.

You can amend the soil to adjust the colour of your hydrangeas. Incorporating a hydrangea colourant encourages blue flowers, while adding garden lime shifts the pH to produce pink blooms. It’s essential to make these changes gradually and monitor the soil pH with a test kit. Note that white hydrangeas and specific cultivars will not change colour regardless of the soil’s pH.

How to Protect Hydrangeas from Frost Damage

Frost can harm hydrangea buds and delicate new growth, especially in colder regions. To prevent frost damage, mulch around the base of the plant with organic material like compost or bark. This provides insulation and helps retain soil temperature.

Cover the plant with horticultural fleece during freezing weather to protect exposed growth. If frost damage does occur, prune back to the first undamaged pair of buds in early summer to allow the plant to recover. With proper care, most established hydrangeas bounce back.

When and How to Feed Hydrangea Plants

Fertilising hydrangeas is crucial for healthy foliage and vibrant flowers. Use a balanced, slow-release fertiliser designed for flowering plants. Products high in phosphorus (the middle number on the fertiliser label) promote abundant blooms.

For blue flowers, incorporate ericaceous compost to maintain the acidic conditions hydrangeas need. Apply fertiliser during the growing season, starting in spring when buds emerge and again in mid-summer. Be careful not to over-fertilise, as excessive nutrients can lead to vigorous leaf growth at the expense of flowers.

How to Maintain Hydrangea Shrubs Throughout the Year

Proper maintenance ensures your hydrangeas stay healthy and beautiful from spring to late summer. Water deeply when the soil feels dry, but avoid overwatering or leaving the plants in standing water. Mulching around the base can help prevent moisture loss while suppressing weeds.

Deadhead faded blooms during the growing season to encourage further flowering and keep the plant looking tidy. While compact hydrangeas often require less care, established plants benefit from occasional pruning and thinning to promote airflow and prevent disease.

How to Incorporate Hydrangeas into Your Garden Design

Hydrangeas’ bold blooms can transform any outdoor space, making them the focal point of your garden design. For height and depth, position larger varieties like hydrangea paniculata at the back of borders. Mopheads and lacecaps make excellent mid-border fillers, while compact hydrangeas are ideal for smaller beds or patio containers.

Experiment with a mix of blue, pink, and white flowers for a striking effect. Hydrangeas can also serve as seasonal table centrepieces, their freshly cut blooms adding a splash of colour indoors. With a bit of creativity, hydrangeas can suit any garden style.

Hydrangeas have always held a special place in my garden. There’s just something about their generous, ever-changing blooms that brings a sense of joy each season. I particularly love their responsiveness to soil pH—it’s like a gardening experiment that rewards you with brilliant blues or vibrant pinks. One of my favourites is Hydrangea paniculata ‘Vanille Fraise’—its soft, creamy flowers that blush to deep pink are simply stunning in late summer. I’ve found that with a bit of regular care, especially getting the pruning and feeding right, hydrangeas will reward you year after year. Whether you’re a seasoned gardener or just starting, they’re a fantastic, forgiving shrub that delivers.

Key Tips for Long-Term Hydrangea Health

• Choose the right hydrangea variety for your garden, such as hydrangea macrophylla, paniculata, or oak-leaved hydrangea.
• Soil acidity determines flower colour—use ericaceous compost or aluminium sulphate for blue flowers and garden lime for pink.
• Prune hydrangeas annually based on their specific requirements, ensuring strong growth and vibrant blooms.
• Protect plants from frost by mulching and covering tender growth during cold weather.
• Fertilise in spring and mid-summer for healthy plants and rich flower displays.
• Consistent care, including deadheading and maintaining soil moisture, ensures hydrangeas thrive year-round.

Hydrangeas are easy to grow and worth the effort. Following these tips, you’ll enjoy stunning, long-lasting blooms in your garden for years.

Check out the RHS excellent Hydrangea article here.

If you like hydrangeas, you’ll love Hydrangea paniculata Vanille Fraise, one of my favourite hydrangeas.

For more information on Shrubs, please click here.

Frequently Asked Questions

Q: How can I ensure my hydrangeas produce abundant flower heads?

A: To encourage your hydrangeas to produce plentiful flower heads, it is essential to cut out one or two of last year’s stems at the base to promote healthy growth. This technique will encourage blooms on this year’s growth. Additionally, ensure your plants receive adequate sunlight and moisture for optimal blooming.

Q: What is the recommended height for planting hydrangeas in a garden?

A: The height required for planting hydrangeas depends on the specific variety. Commonly grown hydrangeas can range from 60 cm to 180 cm tall. For those interested in shorter options, consider Hydrangea macrophylla Miss Saori, which is slow growing and typically reaches a height of about 1m (39in) without pruning.

Q: How do I care for my hydrangeas so they can enjoy their beautiful flowers for years?

A: To care for your hydrangeas, ensure they are planted in well-drained soil and receive appropriate watering. Regularly deadhead the flowers after blooming and prune the previous year’s stems to encourage new growth. This will help ensure that flowers are produced abundantly each year.

Q: Are there any specific hydrangea varieties that are better for beginners?

A: Some hydrangeas are easier to grow, making them perfect for beginners. Varieties like the mophead hydrangea are commonly recommended due to their hardiness and vibrant blooms. Gaining insights from experienced gardeners can also help you choose the best varieties suited for your local climate.

Q: How do the colour and tint of hydrangea flowers change, and what causes this?

A: The colour of hydrangea flowers can change based on the soil pH. Acidic soils typically produce blue flowers, while alkaline soils yield pink flowers. Adjust the tint by amending your soil with garden lime or sulfur or using a hydrangea colourant. Monitoring your soil’s pH can be an interesting project to undertake.

Q: What are some creative ways to use hydrangeas in floral arrangements?

A: Hydrangeas make stunning additions to floral arrangements, serving as a table centrepiece or in bouquets. Their large flower heads provide volume and beauty. Mix them with other blooms or greenery to create a balanced and visually appealing display.