Q.Caring For A Hydrangea, Indoors.
I was given a small hydrangea plant and want to keep it indoors. I live in Arizona and would like to know if I can plant it outside. Will it take the heat we get in the summer? Thank you.
Certified GKH Gardening Expert
Sure! They can grow as houseplants! Here is an article that will help you with that:
https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/potted-hydrangea-houseplant.htm
As far as if it will survive in your area... That will depend on the type of hydrangea that you have. Some will, and some won't. Almost all of them need shade away from full sun, except the Tree Hydrangea.
Here is an article that will help you to know what, general, care requirements they have:
Depends on what type of hydrangea it is, its DNA and where it came from. For example, florist hydrangeas tend to be sold as annuals and are not bred to provide years of enjoyment. They can be sensitive to leaf fungal diseases and be not too winter/summer hardy.
Indoors: Hydrangeas can be kept indoors for limited times such as during winter when they are dormant. They do not perform well indoors here in Texas on a long term basis and start to go downhill after 2-3 years due to lack of humidity. I have to plant them outside or consider them as annuals. If you put them in pots inside, choose a location that gets a few hours of morning sun or even full but very bright shade (but remember that less sun = less blooms; they can still produce blooms in full shade as long it is not dense shade).
Species: You will have slightly less problems with an oakleaf hydrangea (Hydrangea quercifolia). Those are the more drought tolerant of hydrangeas. You will have the most trouble with a Wild or Smooth Hydrangea (Hydrangea arborescens) as it the most heat sensitive here in Texas. Big Leaf Hydrangea or Hortensia (Hydrangea macrophylla) and Mountain Hydrangea (Hydrangea serrata) fall somewhere in the middle. Pee Gee Hydrangeas (Hydrangea paniculatas) also fall somewhere in the middle but they tend to bloom in late summer, just as your/my highest temperatures arrive and the blooms prematurely turn from white to brown many times so, I do not recommend those.
Outdoors: you should chose a location that provides dappled sun or morning sun by 10-11am. I do not recommend sunlight at lunch time over here. The foliage cannot tolerate afternoon or evening sun during the summer months. They need acidic, well-draining soil or you can amend the soil to lower the soil pH using garden sulfur, greensand or aluminum sulfate. If your soil is caliche soil, consider growing them outside in pots with potting soil for ericaceous plants like azaleas, camellias and hydrangeas. The soil should be maintained as evenly moist as possible. The root system is shallow, tiny and fibrous. The roots are typically found in the top 4” of the soil, an area that can be dried out easily by summer winds. Feel free to replant if the location starts to get too much sun. As soon as temperatures typically reach or exceed 85°F, increase the amount of water per watering and-or the frequency.
When to water: try not to water based on a schedule, especially when the weather changes somehow (gets warmer, cooler, windier, less humid, etc.). Insert a finger into the soil (try a few spots around the plant) at a depth of 4” and water if the soil feels dry or almost dry. If you observe that the leaves are turning brown from the edges inwards, the plant needs more water. If you observe that the blooms are prematurely turning brown (they should go through a series of color changes, each last several weeks or a month) then the plant needs more water and-or is getting too much harsh sunlight. Depending on soil type, plant size, weather and many factors, you will need to water then a lot in the summer. I may water mine about 1-3 gallons of water per plant in the spring or 2-5 gallons per plant in the summer. Always water the soil and never the leaves in order to minimize the chances of fungal leaf spots. Use the finger method to know if you need to water in the winter months, when the plant loses foliage and it may not be obvious if the plant is getting dried out.
Did you water enough: when the finger method indicates that the plant needs water, water it and wait for the water to drain. Then insert a finger to a depth of 8” in a few spots and see if the soil feels dry. If it does, you may have missed a spot when watering, the soil does not drain well or you need to use more water when watering.
Wilting: all hydrangeas will wilt a lot in summer number one but Big Leaf and Smooth Hydrangeas will wilt more often here in the south. Wilting occurs when the leaves lose leaf moisture faster than the roots can absorb more water. As long as the soil has sufficient moisture, you can let the plants remain wilted and they will perk up as temperatures go down at night. Then check them in the morning. If they are still wilted, give them a gallon of water.
