12 Things Gardeners Should Never Do When Caring for Hydrangeas
Who doesn’t love hydrangeas? The beautiful blooms are the quintessential cottage garden flower.
Their lush blooms and vibrant colors make them a favorite among gardeners, however, hydrangeas may have a reputation for being fussy,
These delicate beauties require the right care to truly thrive, but with the correct know-how, they’ll reward you with stunning blooms season after season.
If you want to keep your hydrangeas looking their best come spring and summer, avoid these 12 common mistakes – from pruning at the wrong time to incorrectly watering.
1. Planting in the Wrong Spot
Hydrangeas thrive in dappled sunlight—too much shade can lead to fewer blooms, while too much direct sun can scorch their leaves.
Most varieties do best with morning sun and afternoon shade, so choose a location that balances light and protection.
2. Overwatering or Underwatering
Hydrangeas love moisture, but soggy soil can lead to root rot. Water deeply a few times a week rather than giving them a daily light sprinkle.
If the leaves start wilting, they may need more water—especially during hot weather.
3. Pruning at the Wrong Time
Not all hydrangeas should be pruned at the same time. Some, like bigleaf (Hydrangea macrophylla) and oakleaf hydrangeas, bloom on old wood, meaning they set buds the previous year.
Pruning in late winter or early spring will remove these buds, reducing blooms. Instead, trim them right after they flower. Panicle and smooth hydrangeas, however, bloom on new wood and can be pruned in late winter.
4. Using the Wrong Type of Fertilizer
A heavy-handed approach to feeding can result in lush leaves but few flowers.
Avoid high-nitrogen fertilizers, which promote leaf growth at the expense of blooms. Instead, opt for a balanced, slow-release fertilizer or compost to nourish the plant without overwhelming it.
5. Ignoring Soil pH for Color Control
One of the most magical aspects of hydrangeas is their ability to change color based on soil pH. Blue flowers need acidic soil (pH below 6), while pink blooms require alkaline conditions (pH above 7).
If you want to adjust the color, test your soil first and amend it with aluminum sulfate for blue blooms or lime for pink ones.
6. Letting Them Dry Out in Summer
Hydrangeas are notorious for wilting in the heat, especially in dry spells.
Mulching around the base helps retain moisture, and watering in the morning ensures they stay hydrated throughout the day. Be extra vigilant with potted hydrangeas, as they dry out faster than those in the ground.
7. Not Protecting Them in Winter
Harsh winters can damage hydrangea buds, especially for varieties that bloom on old wood.
To protect them, mulch the base heavily in late autumn and consider wrapping them in burlap in particularly cold climates.
8. Crowding Them Too Close Together
Hydrangeas need good air circulation to prevent mold and mildew. When planting, space them according to their mature size—usually three to six feet apart—to give them room to grow and breathe.
9. Forgetting to Deadhead
While not essential, deadheading spent blooms can encourage reblooming and keep your garden looking tidy.
However, avoid cutting too far down the stem, especially for old-wood bloomers, as this may remove next year’s buds.
10. Using Hard Water on Blue Hydrangeas
If you’re aiming for those gorgeous blue blooms, avoid watering with hard water, as it can raise soil pH and turn the flowers pink.
Instead, collect rainwater or use distilled water to maintain the soil’s acidity.
11. Skipping the Mulch
Mulching isn’t just for aesthetics—it helps regulate soil temperature, retain moisture, and suppress weeds.
A layer of organic mulch like wood chips or pine needles can work wonders for your hydrangeas’ health.
12. Neglecting Pests and Diseases
Aphids, spider mites, and powdery mildew can all attack hydrangeas.
Check the leaves regularly for signs of trouble, and treat early with insecticidal soap or neem oil if needed. Good airflow and proper watering habits can help prevent fungal diseases.
