You may be used to seeing hydrangeas planted in the ground, but they also make wonderful container plants once you know how to care for hydrangea in pots. Growing potted hydrangeas is similar to growing them in the ground, but there are a few important considerations to figure out before you get started. Here’s what you need to know to grow and care for these beautiful shrubs.
Hydrangea is toxic to humans and pets.
Can You Grow Hydrangeas in Pots?
Hydrangeas grow well in pots when they receive the proper care. Deciding how long you expect to enjoy them is helpful. If you want only one fabulous season of blooms from the plant, your options are wide open regarding the type of hydrangea to grow and the kind of container to use. However, if you expect your potted plant to last for several years, you need to give the type of hydrangea and container some consideration, depending on your climate.
Best Choices for Potted Hydrangeas
Shorter, more compact varieties of bigleaf, smooth, panicle, and mountain varieties are the best choices for growing hydrangeas in pots, and there are plenty to choose from. For example:
- Bigleaf hydrangea (Hydrangea macrophylla) ‘Wee Bit Grumpy’, ‘Paraplu’, ‘Endless Summer Pop Star’, and ‘Cityline Paris’
- Smooth hydrangea (H. arborescens) ‘Invincibelle Wee White’, ‘Invincibelle Limetta’, and ‘Mini Mauvette’
- Panicle hydrangea (H. paniculate) ‘Little Lime’, ‘Bombshell’, and ‘Bobo’
- Mountain hydrangea (H. serrata) ‘Tiny Tuff Stuff’
Check for hardiness: To safely overwinter your hydrangeas in pots, select one that is one or two zones hardier than where you live. Because the pot will be above ground and more affected by cold temperatures and rapid temperature changes.
Selecting a Container
Choose a container at least 18 to 24 inches deep and wide so the plant’s roots have plenty of room to grow. Be sure it has at least one drainage hole (more than one is better). Inadequate drainage can kill hydrangeas in pots.
If you live in an area with cold winters, avoid clay, terra-cotta, or ceramic pots that may crack when the soil freezes. If you plan to move the container, consider its weight. Once potted, the hydrangea will be heavy, so it makes sense to pot it where you plan to grow it. If you plan on moving it around on your deck or patio, consider a pot with wheels.
Choosing a Location
Whether you plan to grow your hydrangea in a pot for a single season or several years, you need to select a spot that suits its needs with respect to light. Most hydrangeas perform best in a place where they receive four to six hours of sun each day or dappled sun throughout the day. Panicle hydrangeas can take more sun as long as you don’t let them dry out.
All types of hydrangeas benefit from some shade in the afternoon. Try to find a spot that is somewhat protected from the wind; the large leaves of hydrangeas lose a lot of moisture on windy days.
How to Plant Hydrangea in Pots
Use high-quality potting soil, preferably with a slow-release fertilizer that will feed the plant the first season, and mix in some compost for additional nutrients.
- Place the soil mix in the container so that the hydrangea’s root ball fits comfortably. Leave 2–3 inches above the top of the root ball for mulch.
- Tease the roots with your fingers or a garden fork to loosen them and encourage outward growth.
- Set the root ball in the pot and fill in around it with the potting mix, firming it to eliminate air pockets. Make sure the soil level is the same as when it was in its original container.
- Water thoroughly and let it drain. If the soil level has dropped after an hour, add more soil and water again.
- Mulch the soil surface with a couple of inches of organic mulch to retain moisture and keep the soil cooler in summer.
Fertilizing Potted Hydrangeas
Potting soil containing slow-release fertilizer should meet all your hydrangea’s needs during its first year. If it doesn’t, add some to the potting mix before planting, using the amount suggested on the label. Beginning the second year, apply a balanced, slow-release fertilizer in early spring and again four to six weeks later. Don’t apply fertilizer in late summer because it encourages tender new growth that won’t have time to toughen up before the cold weather.
Watering Potted Hydrangeas
Hydrangeas grown in containers can dry out quickly. The plants wilt when they don’t receive enough water, and frequent wilting weakens them, making them more susceptible to pests and diseases. Check the hydrangea for water every day or two; in hot, dry weather, check daily. If the top inch of soil feels dry, water thoroughly.
As the plants grow, the roots take up more space in the container, and plants may need more frequent watering. Water the soil, not the leaves. Wetting the leaves can spread fungal diseases like powdery mildew. Don’t let the plant sit in water, which may cause the roots to rot; use pot feet or pebbles to keep the pot above any standing water in the saucer.
Overwintering Potted Hydrangeas
If you live in a mild climate, your hydrangea will do fine outside, but you’ll need to be mindful of watering throughout the year (less frequently in cooler weather). In colder regions, hydrangeas should be watered thoroughly in the fall and mulched. It is best to leave them outdoors so they are exposed to the seasonal changes. However, they may need some protection from wind or deep freezes. You can protect your plant by moving it to a sheltered location against a house or garage where it still receives some sun and precipitation or by using frost-protecting fabric to cover it.
A dolly makes moving heavy pots around easier as the seasons or your whims change.
Repotting a Hydrangea
If you’ve successfully grown hydrangeas in pots, they reward you by eventually outgrowing their pot. Their growth will slow, and they will produce fewer blooms. That’s most likely because their roots will have used up most of the space, leaving little soil to hold water and nutrients.
At this point, remove it from the container and plant it in the garden or transplant it to a larger pot with fresh soil. If you put it in a larger container, choose one that is just a size or two bigger. Strange as it may seem, plants can languish if placed in a pot that is way too big for them.
