It's a good question, since the potted hydrangeas given as gifts rarely last more than a few weeks. The good news is that they can, as long as you treat them right. Since they can get quite big and produce stunning blossoms all summer long, growing hydrangeas in pots is well worth it.
Planting Hydrangeas in Pots
Hydrangeas do not do very well in smaller containers because their roots are aggressive and quickly fill smaller containers. Smaller containers also dry out too fast for what hydrangeas prefer. We typically recommend getting a medium to large sized planter that is at least 2 feet wide.
First, decide where you'll put the hydrangeas.
Many hydrangeas like morning sun and afternoon shade, so this also makes it easier to give them the growing conditions they prefer. You can also move them around to decorate a patio or other space for a party or special occasion.
Place the container in a sheltered area that receives morning sun and afternoon shade for best results. If they are in a full sun location, you'll need to be extra vigilant about watering. Thoroughly water the shrub a few times a week, or whenever the top inch of soil begins to dry out.
If you purchase the annuals small and make your own pots in early Spring, you can save money but you still are left with dead plants at the end of the season. Hydrangea plants are considered a perennial which will grow back year after year if care for properly.
With special care, indoor hydrangeas can thrive annually. Once the flower heads start to turn brown, trim them off. If not bringing them outdoors, you will need to force a period of dormancy during fall and winter. Move the plant into an unheated room with temperatures around 45 F.
Hydrangeas grow well in gardens, but can also grow in pots. They need well draining soil that has a slightly acidic pH. If these are not the conditions in your garden, I urge you to try planting a hydrangea in a container.
You could try planting the hydrangea outdoors if weather allows, but it's important to remember that most indoor/gift hydrangeas were not developed with outdoor performance in mind. A large number of them are not very cold tolerant and will die in winter in areas colder than USDA zone 7 or 8.
Watering Hydrangeas in Pots
Make sure there is a drainage hole! The hydrangea should be watered thoroughly at least 3 times a week. Always water the plant all the way around the container, not just in one place.
Some gardeners report success in turning their hydrangeas blue by applying coffee grounds to the soil. The coffee grounds make the soil more acidic, allowing the hydrangea to more easily absorb aluminum. In addition, fruit peels, lawn clippings, peat moss and pine needles, are thought to have a similar effect.
The reason for a hydrangea dying is most often due to not enough moisture in the soil. Hydrangeas require the soil to be consistently moist and will droop or die because of drought. Hydrangeas can die due to frost damage, drought, transplant shock and because of too much sun.
Hydrangeas don't make great houseplants long-term. But if you live in areas where the winter temperatures go below 5 degrees on a regular basis, you can plant these in pots and over-winter them in a garage or other area where they can be dormant but not go much below 30 degrees.
Water hydrangeas in pots frequently, so the soil doesn't get dry during their blooming time. While hydrangeas are blooming they require daily watering. When we had an unusual hot spell this Summer, I even watered them twice a day – once in the morning, and once in the evening. That kept them healthy and happy.
Most common hydrangeas prefer a partial sun location - ideally receiving sun in the morning hours and shade in the afternoon. The reblooming Endless Summer® Hydrangea series prefers part shade. These include BloomStruck®, Endless Summer®, Blushing Bride®, and Twist-n-Shout®.
Hydrangea Care Tips
Water at a rate of 1 inch per week throughout the growing season. Deeply water 3 times a week to encourage root growth. Bigleaf and smooth hydrangeas require more water, but all varieties benefit from consistent moisture.
Trimming should be done immediately after flowering stops in summer, but no later than August 1. Do not prune in fall, winter, or spring or you could be cutting off new buds. Tip-pruning the branches as leaves emerge in spring can encourage multiple, smaller flower heads rather than fewer larger flower heads.
When you deadhead hydrangeas, you aren't harming the plants at all. Removing the spent blooms triggers flowering shrubs to stop producing seeds and instead put their energy toward root and foliage development. This makes plants stronger and healthier, so by deadheading, you'll be doing your hydrangeas a favor.
It's a good idea to test soil drainage in the planting area before planting. In Pots & Containers: Hydrangea growing in pots, planters and other containers will appreciate a moist but well-drained soil. We suggest the use of a quality potting soil or potting mix or, better yet, a 50/50 combination thereof.
Miracle-Gro Potting Mix
Coming from one of the biggest and most famous plant care companies, this potting mix will help your plant thrive. It is suitable for most types of plants but is best for vibrant hydrangea species since it will enhance the beauty of the flowers.
Hydrangeas are long-lived shrubs, sometimes living for up to 50 years if properly cared for. They enjoy morning sun but afternoon shade, and they need frequent watering during the growing season. Prune them in the fall after the blooms fade so they can grow on strong stems the following summer.
Most hydrangeas prefer only morning sun. Yet one type of hydrangea can soak up the sun all day: the panicle hydrangea. While they can stand the sun, these do just fine in partial shade, too.
The primary reasons hydrangeas don't bloom are incorrect pruning, bud damage due to winter and/or early spring weather, location and too much fertilizer. Hydrangea varieties can be of the type that blooms on old wood, new wood or both. Old wood is the current year's growth and new wood is next year's (spring) growth.