Hydrangeas are a favorite among gardeners, and it’s easy to see why. With their lush, full blooms and vibrant colors, these stunning plants can transform any garden into a floral paradise and there is a hydrangea species and variety for everyone! Whether you’re a seasoned gardener or just getting started, taking proper care of your hydrangeas will ensure they flourish and produce breathtaking flowers year after year. Here’s everything you need to know about caring for hydrangeas, from planting to pruning and beyond!
If you would like a quick care guide to download and print, grab it here: Hydrangea Quick Care Guide
1. Choose the Right Location
Hydrangeas macrophylla (bigleaf) and serrata (mountain) love bright, indirect sunlight. They thrive best when planted in a spot that receives morning sun but is shielded from the harsh afternoon rays. If your garden gets a lot of afternoon sunlight, consider planting your hydrangeas in a location with partial shade during those hours to prevent the leaves and blooms from scorching. Hydrangea paniculata (panicle) and quercifolia (oak leaf) can take more sun than other types, and if provided enough moisture can thrive even in full sun (6-8 hours). Note “full sun” does not mean “all day sun”. Even the most resilient and sun tolerant plants can use a break from the sun rays at some part of the day, just like you.
2. Watering: Keep the Soil Moist
Hydrangeas are thirsty plants, and they need consistent watering to thrive. Depending on your climate, a general rule of thumb is to provide them with at least 1 inch of water per week. However, during particularly hot or dry spells, or if the hydrangea is placed in more sun than they desire, they may need more frequent watering. The goal is to keep the soil moist but not waterlogged, as soggy roots can lead to root rot. Sufficient water after planting and regularly for the first several years until they are established is critical for best success.
Watering Tips:
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- Water early in the morning or in the evening to reduce evaporation.
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- Use a soaker hose or drip irrigation to water at the base of the plant, avoiding wetting the leaves to prevent disease. Drip irrigation is my favorite approach.
3. Soil: Keep It Rich and Well-Drained
Hydrangeas love rich, well-draining soil. Before planting, mix in compost or other organic matter to enrich the soil and improve drainage. If you’re working with heavy clay or sandy soil, amending it with organic material will help create the ideal environment for your hydrangeas. In heavy clay, fill the hole with water and time how quickly it drains. If it drains very slowly and takes more than 30 minutes to fully drain, you want to pay particular attention to amending the entire planting area to improve draining. Don’t amend only the planting hole. In clay soil conditions, amending just the planting hole is a good opportunity for the hole to hold even more water and contribute to root rot and plant death.
Soil Test: A soil test can help determine if your soil needs adjustments. Hydrangeas generally prefer a slightly acidic to neutral pH (around 6.0-7.0), but if you’re growing bigleaf hydrangeas (Hydrangea macrophylla), the soil pH can also affect flower color (more on that below).
4. Pruning: Get the Timing Right
Pruning hydrangeas can seem daunting, but it’s essential to keep your plants healthy and promote fuller blooms. The timing and method of pruning depend on the type of hydrangea you’re growing:
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- Bigleaf (H. macrophylla), Mountain (H. Serrata), and Oakleaf (H. quercifolia): Don’t prune at all, unless you have dead or damaged wood/stems. If you must prune, prune right after they finish blooming, usually in mid-summer. These varieties traditionally bloom on old wood, so pruning too late will remove next season’s flower buds. But, there are new varieties of bigleaf hydrangea that may rebloom throughout the season. I always recommend those varieties if you are looking to purchase a new bigleaf hydrangea.
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- Panicle (H. paniculata) and Smooth Hydrangea (H. arborescens): These bloom on new wood, so they should be pruned in late winter or early spring before new growth begins or immediately after the stems start to show the buds so you can prune them easier (this is my preference). You may prune these in late fall if your climate exhibits excessive snowfall or ice load to prevent heavy snow or ice from weighing down and breaking or damaging stems. I trim my panicle and smooth hydrangeas by about one-third each year, unless I am attempting to size control them. They are resilient. You can do it!
Pruning Tips:
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- Remove dead or damaged branches to improve airflow.
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- Trim just above a leaf node for best habit
Hydrangeas benefit from feeding, especially in the early stages of growth. A slow-release, balanced fertilizer applied in the spring will give them the nutrients they need for robust growth and vibrant blooms. You can apply another light feeding in mid-summer if needed, but avoid over-fertilizing, as this can lead to lots of leafy growth at the expense of flowers. Avoid fertilizing in late summer and fall, so you are not inadvertently pushing new growth that may be damaged by winter cold.
Fertilizing Schedule:
- Early Spring: Apply a slow-release, all-purpose fertilizer. A fertilizer labeled for woody, blooming shrubs is ideal.
- Mid-Summer: If needed, apply a second, lighter feeding to encourage blooming.
6. Mulching: Protect and Nourish the Roots
Mulching is an important step in hydrangea care, as it helps retain soil moisture, regulate temperature, and suppress weeds. Apply a 2–3 inch layer of organic mulch, such as shredded bark, compost, or straw, around the base of your hydrangeas. Be sure to keep the mulch a few inches away from the stems to prevent rot.
7. Pests and Diseases: Keep an Eye Out
Like any garden plant, hydrangeas can fall victim to pests and diseases. Common pests include aphids, spider mites, and slugs. To keep pests at bay, inspect your plants regularly, especially on the undersides of leaves, where bugs tend to hide. In case of infestation, insecticidal soap or neem oil can help control the problem.
Diseases like powdery mildew or leaf spots can also affect hydrangeas, particularly in areas with high humidity. To prevent fungal issues, make sure your plants have good air circulation by spacing them properly and pruning regularly, or apply a preventative fungicide.
8. Adjusting Bloom Colors (For Bigleaf & Mountain Hydrangeas)
One of the most exciting things about bigleaf hydrangeas (Hydrangea macrophylla) and mountain hydrangeas (Hydrangea serrata) is that their flower color can usually be altered by adjusting the soil pH. The specific color variance is dependent on the variety, and some varieties don’t change color at all (or only slightly).
- Acidic soil (pH below 6.0): Produces blue to purple blooms.
- Alkaline soil (pH above 7.0): Produces pink to red blooms.
To lower the pH and turn your hydrangeas blue, you can add aluminum sulfate to the soil. There must be a presence of aluminum in your soil to change the bloom color to blue – adjusting the pH alone is not enough. For pink blooms, raise the pH by adding garden lime. Make changes gradually and test the soil pH periodically to ensure you’re on the right track. Performing a soil test beforehand will be a good indicator of your starting pH.
Conclusion: Hydrangeas Made Easy
With the right care and attention, hydrangeas will reward you with years of gorgeous blooms. Whether you’re growing the iconic bigleaf varieties or the charming panicle types, keeping their soil rich, providing adequate water, and pruning at the right time will set your plants up for success. By following these simple tips, you’ll have a garden full of healthy, happy hydrangeas that will make your outdoor space pop with color.
Got any more hydrangea questions or tips? Drop them in the comments below! #HydrangeaCare #GardenTips #BloomingBeauty #HydrangeaLovers
