The Ultimate Guide to Cultivating and Nurturing Hydrangeas

During the peak of the summer season, our excitement revolves around one particular shrub: hydrangeas. These beautiful flowering shrubs come in various colors, making them a favorite among gardeners. With an average growth of 2 feet per year, some hydrangea varieties can reach an impressive height of 15 feet. They thrive in growing zones 3 to 9 and require minimal maintenance for them to come back year after year. If you’re wondering how to prune hydrangeas, here are some tips to help you out.

Tips for Planting Hydrangeas Before planting your hydrangea, it’s important to take a few steps to ensure proper growth. Start by giving the plant a good watering while it’s still in the nursery pot. Then, choose a location that provides the right amount of sun or shade for the specific variety of hydrangea you have. Dig a hole that is two times wider than the pot, and plant the hydrangea about 1 to 2 inches above the level of the ground soil. Roughen the sides of the hole with a shovel to help the roots expand beyond the hole. Remove the plant from the pot and loosen or cut any circling roots. Place the plant in the hole and backfill with the existing soil. Make sure to water the area thoroughly. Finally, cover the soil surface with 1 to 2 inches of mulch, avoiding the area closest to the stem to prevent fungal issues. Proper Care for Hydrangeas Hydrangeas are a low-maintenance shrub that can thrive in zones 3 to 9. By regularly watering and occasionally pruning, you can enjoy beautiful blooms for extended periods. Light Requirements The amount of light needed for hydrangeas varies depending on the species and variety. It’s important to refer to the care tag for specific instructions before planting. In general, many hydrangeas do well in locations with full sun to partial shade. Soil Conditions Hydrangeas prefer well-drained soil that contains organic matter and has adequate moisture. Heavy soil can lead to root rot, while soil that doesn’t retain moisture can cause the roots to dry out. If you have sandy or clay soil, adding compost or other organic materials like shredded leaves, coffee grounds, or peat moss will help balance the soil. Watering Hydrangeas are very adaptable to different living conditions, but they do have specific water needs. Newly planted hydrangeas should be watered every one to two days, especially during hot and dry periods. It’s best to water in the morning before the sun reaches its peak, allowing the leaves and roots time to dry before nightfall. Once the hotter months have passed, hydrangeas should be deeply watered two to three times per week. Fertilizing Using a general all-purpose fertilizer with a ratio of 10-10-10 or 12-4-8 is suitable for hydrangeas. Apply a slow-release fertilizer twice a year, in spring and early fall. Spread the fertilizer around the drip line of the branches, not just at the base of the plant, and lightly cover with soil. Winter Care If you live in an area with distinct seasons, it’s crucial to provide winter care for your hydrangeas. Before the ground freezes, make sure to water the plants thoroughly. Apply a layer of compost to provide long-lasting nutrients throughout the winter season. To protect the roots, add a thick layer of mulch. In the spring, remove the heavier coat of mulch after the last frost. If snow or ice is expected, cover the hydrangea’s branches with a breathable material like cloth or burlap. Understanding the Difference Between Deadheading and Pruning for Healthy Plants and Flowers and How to Properly Utilize Each Method

Tips for Pruning Hydrangeas Unlike many other plants, there is no one-size-fits-all approach when it comes to pruning hydrangeas. To effectively prune your hydrangeas, it is important to first understand the specific type of hydrangea you have. Some hydrangea species bloom on old wood, meaning their blooms develop on stems that were produced during the previous growing season. For these varieties, it is recommended to prune them in the summer, after they have finished blooming. This ensures that you do not remove new buds before they have a chance to bloom in the spring. When pruning, remove up to one-third of the stems, focusing on removing the weakest shoots. It is essential to keep several stems of old productive wood and strong new stems, as these will produce flowers in the following season and encourage further growth. On the other hand, there are hydrangea species that bloom on new wood, which refers to the current year’s new stems. For these types of hydrangeas, it is best to prune them in late winter or early spring, just before the new growth begins. Cutting the stems back to the ground during this time will promote healthy growth and abundant blooms. Since each type of hydrangea requires different pruning techniques, it is beneficial to familiarize yourself with the most popular varieties. This will help you provide the appropriate care for your specific hydrangea plant.

Hydrangea arborescens, commonly referred to as smooth hydrangea, is a delightful shrub featuring unbranched stems and charming white flowers in a rounded shape. Standing between 3 to 5 feet in both height and width, it is a compact and versatile plant suitable for various garden sizes. Whether you reside in Zones 4 to 9, this hydrangea will thrive and enchant with its blooms. Interestingly, the flower color remains unaffected by the soil pH, allowing for effortless cultivation in any soil type. Embrace the beauty of Hydrangea arborescens in your garden and enjoy its unique qualities.

Photograph by JACKY PARKER, courtesy of Getty Images Hydrangea paniculata – The Delightful Cone-Shaped Beauty The Hydrangea paniculata, commonly known as panicle hydrangea, is a charming plant that boasts cone-shaped flowers. These lovely blossoms initially bloom in shades of white or lime green before gradually transitioning into a delicate pink hue. In terms of size, this species of hydrangea can reach impressive heights of up to 10 feet, spreading just as wide. Its substantial dimensions make it a commanding presence in any garden or landscape. Thriving in a wide range of climates, the panicle hydrangea is suitable for zones 3 to 8. This adaptability ensures that gardeners across diverse regions can delight in its beauty without any hindrances. One of the remarkable features of the Hydrangea paniculata is its ability to bloom on new wood. This means that even after winter dormancy, the plant can produce an abundance of magnificent flowers on the freshly grown branches. This aspect adds to its allure and ensures that each blooming season is a sight to behold. Furthermore, what sets this hydrangea apart is that its flower color is not influenced by soil pH. Unlike other hydrangea species where soil acidity or alkalinity determines the bloom shade, the panicle hydrangea remains unaffected by such factors. This unique characteristic makes it a hassle-free option for gardeners, as they can enjoy a delightful array of colors without any specific soil adjustments. In summary, the Hydrangea paniculata, or panicle hydrangea, is a captivating plant with cone-shaped blossoms. Its towering presence, adaptability to various climates, ability to bloom on new wood, and independence from soil pH for color development make it an appealing choice for any gardener.

Bigleaf hydrangea, scientifically referred to as Hydrangea macrophylla, is a popular shrub that is wider in shape rather than tall. Its flowering season begins in June in regions with mild climates, while it produces repeat blooms in the middle of summer. In terms of size, it typically reaches heights and widths ranging from 3 to 6 feet. This particular species thrives in zones 5 to 9. An interesting aspect of bigleaf hydrangea is that it blooms on old wood. Additionally, the acidity of the soil plays a significant role in determining the color of its flowers. In acidic soil, the flowers tend to be blue, while alkaline soil results in pink flowers.

Hydrangea quercifolia, commonly known as oakleaf hydrangea, is a unique plant that offers year-round beauty with its cone-shaped flowers that transition from pink to brown. It can reach a height and width of 8 feet and is suitable for zones 5 to 9. Unlike other hydrangea varieties, this plant blooms on old wood and is not affected by soil pH when it comes to flower color. If you’re interested in propagating hydrangeas, timing is crucial. The best time to do so is during spring. On a pleasant spring morning, gather a handful of 6-inch cuttings without any flower buds and make sure there is at least one node present. The node is the point where the current stem connects to another stem, and this is where new roots will emerge. To promote successful rooting, dip the cut end of each cutting into a hormone rooting powder, which can be conveniently purchased online. Then, plant the powdered end around 2 to 3 inches deep in a pot filled with soil. Place the pot in a location with indirect light and lightly water the soil to keep it moist until roots start to develop. This process usually takes around two to three weeks, after which the cutting will be ready to be transplanted. However, it’s important to note that not all hydrangea varieties can be propagated. Propagation of patented plants is illegal. Breeders have the right to protect their investments and continue introducing new plant varieties for gardeners to enjoy. Before attempting to propagate a hydrangea, always check the plant’s pot or description for patent numbers, trademarks, or PPAFs to ensure you’re not infringing on any regulations.

Changing the Color of Hydrangeas Altering the color of hydrangea blossoms can be achieved by adjusting the acidity or alkalinity of the soil. To do this, begin by testing the pH of your soil using a test kit from a local nursery. For blue blooms, you’ll need acidic soil with a pH lower than 7, which can be achieved by adding sulfur or aluminum sulfate. For pink blooms, you’ll need alkaline soil with a pH higher than 7, which can be achieved by adding lime to the soil. Common Issues with Hydrangeas While hydrangeas are generally easy to care for, they can encounter some common problems. Powdery Mildew Powdery mildew is a prevalent disease that affects hydrangeas. It is characterized by a white fungus that blocks sunlight from reaching the leaves. In severe cases, the leaves may turn yellow, brown, and drop off. This issue is more common in shaded and crowded areas. To prevent infections, improve air circulation by pruning and reduce humidity. Treat the disease with a fungicide specifically designed for this type of infection. Begin treatment at the first sign of the disease and follow the product label’s recommendations. Bacterial Leaf Spot Hydrangeas are also susceptible to bacterial leaf spot, particularly the oakleaf and panicle varieties. This disease appears as dark brown spots with defined edges, causing the leaf tissue to rot. Improve air circulation through pruning and avoid overwatering the soil to prevent this issue. Treat bacterial leaf spot with copper bactericides, which can be found at nurseries and garden centers. Aphids An infestation of aphids can cause yellowing or withering of hydrangea leaves. These tiny green or black pests can be found beneath the leaves. To treat aphids, wash the leaves with an insecticidal soap or use a strong spray of water from a garden hose. Beetles Beetles, such as Japanese beetles and rose chafer beetles, can also affect hydrangeas. Identify the specific beetle species to determine the appropriate treatment plan. For rose chafers and Japanese beetles, remove the bugs by hand and submerge the leaves in warm soapy water. Prevent future infestations by applying neem oil to the leaves. Month-by-Month Hydrangea Care Guide To help you keep track of the monthly care requirements for hydrangeas, we have compiled a guide: March: Prune hydrangeas that bloom on new wood by cutting back about one-third of the plant’s height. Begin a fertilizer routine using a granular option formulated for woody plants. April: Continue the monthly fertilizer routine and protect plants from garden pests. If you have a hydrangea variety that changes color based on pH, test your soil. May: Apply another round of fertilizer if you have an established schedule. Add a layer of shredded bark mulch around the roots to keep hydrangeas cool and moist during the upcoming heat. June: Administer another round of fertilizer and provide supplemental water if the weather is hot and dry. July: This is when varieties that bloom on old wood will peak, and those that require heavy pruning to blossom on new wood should start flowering. Deadhead early bloomers to encourage further growth. August and September: No fertilization is needed during these months. You can enjoy the fruits of your labor and even cut and display the hydrangeas. October: Your hydrangea will likely be dormant at this stage. Remove any foliage with leaf spots to minimize the risk of reinfection next year. Add a layer of mulch for added winter protection. Prune hydrangeas that bloom on old wood. November to February: If you have hydrangeas that bloom on old wood, you’re done for the season as they will remain dormant. If you have varieties that bloom on new wood, you can prune them during these months or wait until March.

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