How to Water Hydrangeas for Optimal Growth and Plant Health

If you’re new to gardening, it can be hard to know exactly when to water your plants, especially when you start to consider that different plants have different watering requirements. And while some plants thrive in drought conditions (when you forget to water them)—others, like your hydrangeas, will not. Add to that the many different kinds of hydrangeas and their range of exciting colors, and you have a relatively complicated watering scheme to work out. Luckily, most hydrangeas have similar requirements to thrive, including a rich bed of moist, well-drained soil. We’ll dive into all the details on when and how to water your hydrangeas here. 

Watering Recently Planted Hydrangeas

Like any newly planted member of your garden, a recently planted or propagated hydrangea will need a bit more water than an established one. The trick with most new plants is to avoid letting the soil dry out while the roots are getting established, which typically takes two to three weeks. 

One way to go about this is by getting acquainted with your soil. Depending on the conditions of your garden and how much wind, rain, and sunshine it gets— your soil will dry out at a different rate. Since most hydrangeas like part-shade, you can also help them from getting too dried out by planting them in a place that doesn’t get too much sun and is protected from strong winds. 

Determining the Amount of Water for Your Hydrangea Plants

To figure out how much water your new hydrangea needs, start by watering it two or three times per week (less in spring and fall and more in summer) and checking the soil in between waterings. Use your finger to feel into the soil around the base of the plant and check for dryness. If your hydrangea shows signs of dryness (like drooping leaves), you may need to increase your watering regimen. 

Just remember, with larger hydrangea plants (like trees and shrubs), that less frequent but deeper waterings are better than more frequent shorter ones. In other words, the best way to water a hydrangea is by letting a hose run at low pressure at the base of the plant for several minutes. A long, deep watering two to three times per week will be much more effective (since it has to reach a more extensive root system deeper in the soil) than short topsoil watering with a watering can. 

Pro tip: Water your plants in the morning or early evening to avoid rapid evaporation in the midday heat. You’ll also want to consider fertilizing your hydrangeas a couple of times each growing season and cutting back hydrangea plants at the season’s end.

Watering Established Hydrangeas

Once your hydrangea is established (usually after a few weeks), you’ll want to continue to provide a rigorous hydrangea watering schedule that allows the plant to thrive in its preferred environment: Moist, well-drained soil. Remember, moist doesn’t mean soaked, and a hydrangea sitting in a puddle of water because the soil isn’t draining won’t be happy either. You might also consider how much moisture your hydrangea gets from your garden. If you live in a humid climate or your plants are close together in the garden (and sharing moisture), you won’t need to water as frequently as in a sparsely planted or drier garden. 

Monitor your hydrangea for signs of over or underwatering, and check the soil between waterings to determine if you need to increase or decrease the amount of water you provide. Remember that certain weather conditions (like very hot or windy days) can cause moisture in the soil to evaporate faster, which might mean you need to water more often to keep your hydrangea happy. 

Another trick to ensuring your established hydrangeas get the water they need? Make sure you have a thick layer of mulch protecting the base of your plant. While your mulch shouldn’t touch the bark of the plant, annual or bi-annual mulching around the base of your plants can help to lock in moisture and feed your soil as it decomposes. 

Water Hydrangeas in Pots

There’s no way around it: Hydrangeas in pots will have to be watered more frequently than those in the ground. Because it’s living in a smaller space, you can expect this space to dry out more quickly than the ground will. To keep your potted hydrangea happy, try watering it every other day in the summertime. If the soil seems too wet between waterings (remember, they like moist, not soaked soil), decrease your watering regimen to every third day. 

The good news about potted hydrangeas is that it’s relatively easy to ensure your plant is draining properly, making it very unlikely your plant suffers from any of the common “overwatering” pitfalls. You’ll obviously want to plant your hydrangea in a pot with drainage holes, and be sure the excess water drains properly each time you water it. 

Watering Indoor Hydrangeas

Much like your outdoor potted hydrangeas, you’ll want to water your indoor ones a bit more frequently than those planted in the garden. You can water your indoor hydrangea once every few days (more if the pot is very small and less if it’s larger). Use your finger to check the moisture content in between waterings. 

Another trick to keeping your indoor hydrangea happy? Placement. Indoor hydrangeas do best in cool rooms with plenty of light—but not too much direct sun. Some morning sun with afternoon shade is best. You’ll also want to consider transplanting your hydrangeas into the garden at some point since outdoor plants tend to suffer from various garden pests and diseases when kept indoors for too long. 

Common Signs of Overwatering Or Underwatering

It can be tricky to know exactly how much water your hydrangeas need to be happy. Here are some telltale signs of overwatering or underwatering to watch for. 

Overwatering Hydrangeas

If your hydrangea starts to have yellow, brown, and mushy leaves, you might want to check how wet the soil is around the base. Overwatering (which often happens when soil isn’t draining properly) can lead to root rot and cause a moldy smell at the base of your plants. Other signs of overwatering include consistently wilted flowers or fewer blooms than normal. 

Once you’ve determined your plant is being overwatered, you’ll want to let the soil dry out completely before watering it again. You may also consider moving your hydrangea (or amending the soil) for better drainage. Once the soil feels dry, at least down to the top four inches, you can begin watering again. 

Underwatering Hydrangeas

Underwatered hydrangeas look very similar to other under-watered plants: dry, with burnt or yellow and brown leaves that crack or crinkle to the touch. Underwatered hydrangeas likely won’t have as many blooms or as much new growth as a healthier, well-watered one. 

Addressing this problem is fairly easy—just start providing more water. Give your hydrangea a good long drink at the first sign of underwatering, and set reminders to maintain a schedule of watering one to three times per week, depending on how quickly your soil is drying out between waterings. 

Seasonal Considerations

During the hydrangea growing season (spring through fall), it’s good to maintain a frequent watering schedule for your hydrangeas. At the beginning and end of the season, your hydrangea will likely require less water than it will in the long, hot summer days. Similarly, a heatwave or string of windy days might mean you want to water your hydrangea more often. 

In the winter months, most plants go dormant and don’t require regular watering. If it’s an especially dry and mild winter, you might water your plants once every other week to ensure they don’t dry out completely. 

It’s worth noting that hydrangeas are considered toxic, so it’s prudent to wear a pair of gardening gloves throughout the process.

Best Types of Water for Hydrangeas

When watering your hydrangeas, most types of water will work just fine. This includes rainwater, tap water, or filtered water. Remember if your water contains any added chemicals (like excess chlorine from city water or lots of salt from softened well water). If either of these things are true, then you might want to consider a more natural alternative (like collected rainwater or unsoftened water from a well) for your plants—since they may not take kindly to overly processed or mineralized water. 

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How to Water Hydrangeas – The Final Word

Adequately watering hydrangeas isn’t rocket science, but it takes some observation and commitment (like all gardening) to get it right. Start by noticing how quickly your garden soil dries out and how much water your hydrangeas need to thrive. Once you better understand the conditions of your garden and the requirements of your plants—you’ll be set up for watering success.

To enjoy the fruits of your labor for longer, see our essential guide to how to cut hydrangeas for a vase or bouquet arrangement.