Hydrangeas are one of the most beloved flowering shrubs in gardens across the world. With their large, vibrant blooms and versatility, these stunning plants can bring colour, texture, and a touch of elegance to any landscape. However, many gardeners, especially those new to hydrangeas, often find themselves perplexed by how to grow and care for them. Whether you are a novice or a seasoned gardening pro, this guide will help you master the art of hydrangeas, from planting to pruning, so you can have the most beautiful hydrangeas on the block.
This article is brought to you by Baseline Nurseries in London, Ontario, in partnership with Proven Winners, one of the top plant breeders. Let us dig into everything you need to know to grow these gorgeous blooms right in your own backyard!
Understanding Hydrangeas: Different Varieties and What They Need
Before diving into tips for growing and pruning hydrangeas, it is important to understand the diverse types available. Hydrangeas come in several varieties, and each type has its unique growth habits, blooming schedules, and pruning requirements. Here is a breakdown of the most popular types of hydrangeas:
- Characteristics: These hydrangeas are famous for their large, round blooms that can be pink, blue, purple, or even white. The colour is influenced by the soil’s pH level—more acidic soils produce blue flowers, while alkaline soils yield pink blooms.
- Best for: Part-shade to full sun.
- Pruning tip: Bigleaf hydrangeas bloom on old wood, meaning they set buds in the fall. Therefore, prune them right after they bloom, and avoid heavy pruning in late winter or early spring.
- Characteristics: These hydrangeas feature cone-shaped flowers that start off white and gradually change to pink or red as the season progresses.
- Best for: Full sun to partial shade.
- Pruning tip: Panicle hydrangeas bloom on new wood, which means they can be pruned back in late winter or early spring to encourage fresh growth and large blooms.
- Characteristics: Known for their round, white flower heads, the most popular variety is ‘Annabelle.’ They thrive in both sun and partial shade.
- Best for: Part-shade to full sun.
- Pruning tip: Like panicle hydrangeas, smooth hydrangeas bloom on new wood. Prune them in late winter or early spring for a healthy burst of growth.
- Characteristics: These hydrangeas are named for their distinct oak-like leaves and beautiful, cone-shaped blooms that transition from white to pink to red as the season progresses.
- Best for: Full sun to partial shade.
- Pruning tip: Oakleaf hydrangeas bloom on old wood, so avoid pruning them in late winter. Instead, prune after blooming to maintain their shape.
How to Grow Hydrangeas: A Step-by-Step Guide
Growing hydrangeas is fairly easy, but to get the best results, you need to follow some basic steps to create the ideal environment for them to thrive. Here are the key tips for success:
- Choose the Right Location
Hydrangeas are adaptable, but they do best when planted in a location with the proper balance of sunlight and shade. For most types, a location with morning sun and afternoon shade works well. Too much sun can cause wilting, while too much shade can result in fewer blooms. If you are growing hydrangeas with blue flowers, aim for slightly acidic soil to enhance the colour.
- Prepare the Soil
Hydrangeas love moist, well-drained soil. Test the soil’s pH before planting—hydrangeas tend to prefer a slightly acidic to neutral pH (between 5.5 and 7.0). If you are looking to change the bloom colour of your hydrangeas, you can adjust the soil’s pH by adding amendments. For example, adding sulfur can acidify the soil and turn your blooms blue, while lime can alkalinize the soil and turn them pink.
Before planting, mix in organic matter, such as compost, to enrich the soil and improve its drainage capabilities.
- Watering and Mulching
Hydrangeas need consistent moisture, especially during hot summer months. Water them regularly, but avoid overwatering, as this can lead to root rot. A layer of mulch around the base of the plant helps retain moisture, suppress weeds, and regulate soil temperature. Mulch also prevents the roots from drying out, which is especially important for newly planted hydrangeas.
- Fertilizing
Hydrangeas are moderate feeders. Use a balanced fertilizer with equal parts nitrogen, phosphorus, and potassium (such as a 10-10-10 formula) in the spring before new growth begins. Avoid heavy fertilization, as it can encourage too much foliage growth at the expense of blooms. For blue hydrangeas, consider using a fertilizer specifically formulated for acid-loving plants.
- Pruning Hydrangeas: A Guide to Perfect Blooms
Pruning is one of the most important aspects of hydrangea care. The timing and method depend on the variety you are growing. Here is a closer look at how to prune hydrangeas based on their type:
- Bigleaf Hydrangeas: These bloom on old wood, so it is important to prune them right after they finish flowering in late summer or early fall. Avoid heavy pruning in winter or early spring as this can remove the buds that will bloom the following year.
- Panicle and Smooth Hydrangeas: These hydrangeas bloom on new wood, so they can be pruned back in late winter or early spring before new growth starts. Cutting them back in early spring encourages strong growth and large blooms.
- Oakleaf Hydrangeas: Prune these in late winter to early spring before new growth appears. Like Bigleaf hydrangeas, they bloom on old wood, so minimize pruning to maintain their shape while preserving the bloom potential.
- Deadheading and Cutting Back
Deadheading, or removing spent blooms, helps improve the appearance of your hydrangea bush, but it is not always necessary for the plant’s health. Cutting back dead flowers can make your hydrangeas look neat and tidy, but if you are trying to preserve the seed heads or plan to cut some flowers for arrangements, you can leave them intact.
- Winter Care
In colder climates like London, Ontario, hydrangeas need a bit of winter protection to survive the harsh cold. For Bigleaf and Oakleaf hydrangeas, consider adding a layer of mulch around the base to protect the roots from freezing. You can also wrap the plants with burlap or other breathable material to shield them from winter winds and frost.
Final Thoughts
With the right care and attention, hydrangeas can become the standout feature of your garden. Whether you are looking to create a vibrant colour display or add a touch of elegance to your landscape, these beautiful blooms will surely impress. By selecting the right variety, providing optimal soil, and watering conditions, and mastering the art of pruning, you can enjoy breathtaking hydrangeas year after year.
At Baseline Nurseries, we are proud to be your go-to destination for all things gardening. For over 50 years, our dedicated staff has been helping London and surrounding areas grow beautiful landscapes. We specialize in a wide range of native and ornamental trees, shrubs, perennials, and large caliper trees—everything you need to create your own outdoor masterpiece. Our knowledgeable team has a deep love for trees and gardening, and we take great care in nurturing plants from seedling to sapling and beyond.
In addition to hydrangeas, you’ll find an extensive selection of garden favourites, fertilizers, grass seed, top dressing soil and everything necessary to create a lawn that’s the envy of your neighborhood. Whether you are an experienced gardener or just starting, we are here to guide you every step of the way.
So, why not stop by Baseline Nurseries for all your gardening needs? Let us help you cultivate the garden of your dreams. See you soon!
