Hydrangeas are gorgeous plants that feature large globes of small blooms surrounded by jagged-edged medium-green leaves. They look spectacular growing in your yard, but the hardier blooms are also a fantastic addition to any indoor garden. They don’t need a ton of special care, so if you can keep up with what they do require this plant will add a much-needed touch of color to any home. Join us in this hydrangea care guide, and learn everything you’ll need to know to grow this fabulous plant both indoors and out.
Container
Hydrangeas are technically a shrub, so they need slightly more room than some other indoor plants. A medium or large container will give the root ball the space it needs, allowing the plant to grow and spread as it sees fit. Make sure that your chosen container has proper drainage, and consider adding an inch or two of pebbles to the bottom for this purpose. If your container doesn’t have drainage holes, carefully drill one or two in the base before potting your plant.
Outside of that, hydrangeas don’t require any special type of container or considerations. Most popular types like clay or plastic will work, as will any other container type assuming it has holes for drainage.
Soil
When preparing a pot for your hydrangeas, use well-draining, slightly acidic soil. For some species, you can even alter the pH level to change the color of the flowers. For instance, a lower pH of about 5.5 will maintain blue flowers on your hydrangea. Higher pH levels between 5.5 and 6.5 will create purple or pink blooms, while a pH of 7 or higher will cause red blooms. Of course, not every species will respond this way, so check the type of hydrangea you have before playing with the pH levels.
In most cases, you can simply purchase potting soil at your local hardware or garden store. There are also acidic soil mixes that are perfect for hydrangeas. These provide the perfect base to start from without needing to manually mix and test your soil.
Watering
When hydrangeas are blooming, they need consistent watering every week or so. If you’re unsure if your plant is thirsty, insert your finger about 3 inches into the soil. If it is semi-dry, add water until you see moisture leaking from the drainage holes. Wilted blooms are also a sign of a thirsty plant, so keep an eye on those flowers.
During the growing season, you’ll likely need to water your hydrangea more often, especially during those extra-hot days. When the plant stops blooming, you can reduce how often you water, though you shouldn’t let the soil dry completely.
Watering with distilled or rainwater is best, though if none is available, you can use tap water for your hydrangeas. Be sure to let it sit out overnight beforehand to allow the chlorine and other chemicals in the water to evaporate before adding it to your plants.
Light
Hydrangeas require a lot of light when grown indoors, though they prefer bright, indirect light to the harsh rays of direct sunlight. Placing them in a south-facing window will give them plenty of light. An east-facing window will also provide this pretty plant lots of soft, morning light. The more light the hydrangea gets, the more blooms you’ll see, though direct afternoon light will burn the foliage and flowers.
For indoor growth, grow lights are a great option. A few hours under a grow light per day is usually more than enough to supplement some indirect sunlight. Keep in mind that grow lights tend to be less intense than natural light, so adjust the timings accordingly if you’re relying heavily on artificial light.
Fertilizer
During the hydrangea’s growing season, it’s a good idea to add fertilizer to the soil to ensure it’s getting the nutrients it needs to thrive. A water-soluble liquid fertilizer is best, though you may want to dilute it to half-strength to avoid damaging the hydrangea’s roots. You can add the fertilizer to your watering can for weekly applications. A balanced fertilizer is a good option, though one higher in phosphorus will encourage healthier blooms.
Temperature
Hydrangeas prefer cooler temperatures between 50 and 60 degrees Fahrenheit, which is the best temperature range if you want consistent blooms. If you notice the leaves turning brown or crunchy around the edges your hydrangea is overheated, so shift its placement to cool it down again.
Keep it away from furnace or air conditioning vents for a more consistent temperature. During its dormant season, you can move it somewhere with a temperature of about 45 degrees Fahrenheit until it begins to grow again. It also requires less light during this time, so it’s generally okay to move it to a spare room in your home or even a garage depending on your local climate.
Humidity
Medium to high humidity levels keeps your hydrangea happy and healthy, while too much dry air can cause wilted leaves and flowers. If your home is too dry, place a humidifier near the plant to increase moisture in the air. You can also place a humidity tray beneath the plant. These are easy to make using a small tray filled with rocks and water. These add moisture to the air without soaking the soil.
Check out our full article on humidity for more tips on boosting the local humidity around your plants.
Pruning
Hydrangeas don’t need a lot of pruning, though if you are going to prune one, it’s best to do so immediately after the end of its blooming cycle in the summer. As the flowers fade, you can remove them to keep the plant tidy and encourage new bunches to grow. You can also trim the foliage to maintain the size and shape of the plant; this encourages new growth without causing the plant to develop a larger root system.
Repotting
Hydrangeas only need to be repotted every two years, though you don’t always need to use a larger pot for them. You can remove the plant from the pot, brush the soil away from the root ball, and then plant it in the same container with new soil. If you want a larger hydrangea plant, choose a new pot one size larger to repot it in, giving the roots a bit more room to spread out.
This process helps keep the soil fresh, and prevents the roots from balling up. If your roots become too tightly entangled it can interfere with your plant’s ability to get water and nutrients from the soil. By breaking it apart every couple of years, you ensure that your plant stays healthy and is able to feed properly.
Propagation
To propagate hydrangea plants, cut a healthy stem off the main plant that is at least 4 inches long. The best time for this is in the spring or early summer. Remove the lower leaves from the stem. Then place the cut end of the stem into a container of potting soil, add water, and place it somewhere that receives bright, indirect light. After 2 to 3 weeks new roots should begin to form.
After propagation, it’s not uncommon for the new plant to not flower, or do so weekly, in its first year. Give it proper care, and you’ll likely see it back at full strength the following summer.
Growing Hydrangeas Outdoors
Growing hydrangeas outdoors isn’t that different from growing them indoors, though you do need to take some extra precautions. The best time to plant them is in the fall, though you can also plant hydrangeas in the early spring. This gives them plenty of time for the root system to become established before the hydrangea begins to bloom.
Hydrangeas prefer shady areas, so when planting them outside, it’s best to place them beneath trees. The canopy of leaves overhead gives those delicate blooms the protection they need from the harsh sunlight. Placing them on the east side of your home is best, ensuring they get the soft morning sunlight rather than the harsh afternoon rays.
Outdoor hydrangeas, whether in a pot or planted in a garden, like the same consistently moist soil as indoor plants. Water them when the top inch of the soil is dry, though try to avoid the leaves and blooms when watering. Adding a layer of mulch around the base of the plant helps to maintain its moisture while reducing weed growth.
When growing hydrangeas outdoors, you don’t need to fertilize as often. You can add a slow-release fertilizer in the early spring and then again before summer for healthy plants and consistent blooms.
Not all hydrangeas can handle the icy temperatures of winter, so check the variety you’re growing to see if it will survive the colder months outdoors. If not, you can pot the plant and move it indoors until after the last frost in spring. Hydrangeas left outside during the winter can be covered using a burlap screen to protect any buds that have already formed.
Pests are always a problem with outdoor plants. For hydrangeas, the pests to watch for are aphids or red spider mites. Plant diseases, like powdery mildew or leaf spot, could also affect these shrubs, so watch for signs of these issues. Homemade or store-bought pesticides and fungicides can take care of these outdoor plant problems.
Hydrangea Care Guide
Caring for hydrangea, whether outdoors or indoors, is easy given a little knowledge. The above tips should give you everything you need to know to start growing these beautiful plants in your own garden. As always, feel free to reach out if you have any questions. The team here at Theindorogardens.com is always ready to help fellow gardeners.
Hydrangea FAQ
Does Soil PH Affect Hydrangea Colors?
It can, but only for certain varieties. White Hydrangeas will typically not change colors in response to soil PH.
Where Should You Plant Hydrangeas?
You want to select a location that gets a good amount of bright, but indirect sunlight. You want to avoid areas of heavy shade, but also avoid areas that get intense mid-day sun.
Do Hydrangeas Grow Back Every Year?
Yes, hydrangeas can grow back as long as they are not killed in the winter. Certain varieties are not bred to survive the winter, so make sure to do some research on your variety before making long term plans.
