Not your typical indoor plant, the hydrangea can be grown indoors, under certain conditions. Although, if kept outdoors, it requires much less attention and does much better.
That said, if you make a few adjustments in their care regimen and pick from a variety that’s more adaptable to indoor growing conditions, you can turn the “foil wrapped” hydrangea that was grown for a one-time show into a veritable houseplant.
Below I’m going to cover what to watch out for if you want to keep your hydrangea indoors, how to make it bloom and which varieties you should pick to grow indoors.
Growing Hydrangeas Indoors
Before I delve into the ins and outs of keeping hydrangeas indoors, I’ll preface this guide with a few things.
Hydrangeas that come from greenhouses may not be a variety that survives the winter climate in your area, so even if you wanted, you couldn’t transplant it outside.
Secondly, hydrangeas require a period of dormancy that is triggered in the plant by cold setting in during late fall and winter. This can be difficult to mimic indoors, but not impossible.
Hydrangeas that are grown exclusively indoors, tend to lose their vigor, have trouble blooming, and draw insects and pests.
I say all these, so you don’t feel bad if your hydrangea doesn’t make it or doesn’t live as long, despite your best efforts.
Now, let’s see how against all these odds, you may still offer your hydrangea an environment that could sustain its growth and development, even indoors.
– Light Requirements
Outdoor hydrangeas thrive in full sun to partial shade. Indoors, hydrangeas require bright light, but not intense, direct light that could scorch their leaves.
Place your hydrangea in a well-lit room, near a bright window so it gets plenty of sunshine throughout the day.
As with outdoor hydrangeas, indoor hydrangeas also require moist soil. Hydrangeas that come in small pots from nurseries or greenhouses need to be transplanted to a bigger pot or container.
The potting medium in small pots tends to dry out much faster, leaving your hydrangea dehydrated. The soil of hydrangeas should be moist, not wet. You should never allow the soil to become bone dry.
You should also ensure that the air isn’t too dry indoors, which is often an issue. Increase humidity levels around your hydrangea either by using a humidifier or by using a tray of pebbles to which you can regularly add water to evaporate.
I also don’t recommend that you water them with tap water. If you do, make sure the tap water rests overnight so that chlorine can evaporate. Rainwater is best for hydrangeas.
– Soil Type
The type of soil that hydrangeas enjoy is a fast-draining, well aerated one that retains some moisture, but does not become waterlogged.
Compost, peat moss and perlite should make up the soil mix of hydrangeas to create a fertile, yet well-draining mixture.
For indoor hydrangeas, I recommend a weak fertilizer or a slow-release fertilizer that you add when planting the hydrangea. When adding a slow-release fertilizer at planting, you can also add a bit of compost to the soil later during the growth and blooming season.
With the weak solution, you will need repeat applications every 7-14 days, depending on dosage recommendations.
Regardless of the type of fertilizer, use one that’s specially formulated for hydrangeas or acid-loving plants.
Hydrangeas have trouble blooming indoors, so a fertilizer can help with that too, although it’s best to move your hydrangea outdoors as much as possible during the summer.
As your hydrangea grows, it will require repotting. If it gets too tall, it will also need pruning. Be careful not to cut down on old wood if your hydrangeas bloom on old wood or cut down new wood if your hydrangea variety blooms on new wood.
Indoor Hydrangea Varieties
The mophead hydrangea, Hydrangea macrophylla, is the hydrangea variety that does best indoors. Other varieties aren’t as well-suited for indoor growing.
There are several cultivars of the Hydrangea macrophylla that you can choose from. The Endless Summer cultivar blooms abundantly during summer and produces pale blue blooms. It’s also one of the cold-hardiest cultivars.
Other popular cultivars include the snowy white blooming Libelle, the Nikko Blue with lavender blooms and the All Summer Beauty known for its deep blue blooms.
You can try your hand at growing other hydrangea varieties too, but your time will be better spent on these because of their higher adaptability.
Will Hydrangeas Bloom Indoors?
Getting hydrangeas to bloom indoors can be tricky. As I mentioned, hydrangeas require a dormancy period triggered by cold setting in as fall comes to an end.
After the dormancy period ends and temperatures rise again, the hydrangea exits its winter slumber, its metabolism springs into action, and the plant produces new growths and, eventually, blooms.
This duality is hard to recreate indoors. So, you need to improvise. In fall, as temperatures drop, you need to move your hydrangea to a cool room. The temperature in the cool room should be around 45 degrees F.
In early spring, you can move the hydrangea in a warmer room to trigger the growing and blooming period. Outside of the dormancy period, hydrangeas that are grown indoors require temperatures around 50-60 degrees.
If you can create an environment with these conditions, you can help your hydrangea produce blooms even indoors.
All things considered, if you have a terrace, you should move your potted hydrangeas outdoors during summer as much as possible.
Outdoor conditions are terribly difficult to recreate indoors and hydrangeas that grow in the garden, even in pots or planters, do much better compared to those grown indoors.
Hydrangeas are not cultivated for indoor growing. They’re quintessentially garden plants, but some varieties can be grown indoors with a bit of extra care and attention.
To make things easier on yourself, choose from cultivars that are more likely to be happy with indoor growing conditions like mophead hydrangea varieties.
Bright light, well-draining potting soil, coupled with regular watering and temperature control are crucial to keep your hydrangea happy indoors.