Care Of Indoor Azaleas: Tips For Growing An Azalea Houseplant
Greenhouse azaleas are those beautiful, multicolored joys of spring, those bright spots in the grocery store or garden nursery when everything else is winter gray. Their bright beauty has caused many a gardener (and many non-gardeners) to ask, “Can you grow azalea indoors successfully?” The answer is, “Of course you can!”
Tips for Growing an Azalea Houseplant
You can grow azalea indoors much like any other houseplant, but as with other blooming plants, there are a few tricks you need to know about the care of indoor azalea if you want to keep them blooming year after year.
The first step in growing an azalea houseplant is to choose the right shrub. You are looking for greenhouse azaleas, not hardy azaleas, which are only grown outdoors. Both are Rhododendrons, but different sub genres, one of which is only hardy to USDA plant hardiness zone 10. That’s the one you want.
Greenhouse azaleas aren’t always marked as such, but they will almost always be sold indoors and usually come with that decorative foil wrapping around their pots. Look for a plant with only a few buds open and showing color. That way, you’ll be able to enjoy that first full bloom for a longer period of time.
Flower buds should look healthy and be at different stages of development as a sign they are actively growing. An azalea houseplant with yellowed leaves isn’t healthy. Look under the leaves as well. That’s where those pesky whiteflies and mealybugs dwell. They love azaleas.
As houseplants, many growers ship azaleas in clear plastic sleeves. These sleeves are meant to protect the plant in shipping, but they also trap the ethylene gas released by the plant, which can cause leaf drop. Try to find a retailer who removes them or, if you can’t, remove it from your greenhouse azalea as soon as you get it home.
Care of Indoor Azalea
In their natural environment, these plants live in the understory of high trees. They thrive in cool, filtered sun. Azaleas as houseplants do best at cooler temperatures, ideally around 60-65 F. (16-18 C.). Cooler temperatures will also help the blooms last longer. Keep them well lit, but out of direct sun.
Moisture should be your greatest concern in the care of indoor azaleas. Never allow your plant to dry out. While watering from the top may provide sufficient care, indoor azaleas enjoy the occasional dunk, pot and all, in a larger container of water. When the bubbles stop, pull it out, and let it drain. Whatever you do, don’t let these plants dry out. Keep them damp, not soggy, and don’t fertilize until flowering is complete.
At this point, the lives of most azaleas as houseplants are over, because this is where most people throw them away or plant them in the spring garden for their foliage, allowing Mother Nature to do the deed with frost the following fall.
Getting Greenhouse Azaleas to Rebloom
Can you grow azalea indoors and get it to rebloom? Yes. It isn’t easy, but it’s worth a try. Once the blooms have faded, give your plant a little more light and fertilize it with an all-purpose liquid fertilizer every two weeks. When the weather warms, plant it pot and all in your outdoor garden or keep the pot in a semi-shaded area indoors or out. Since they prefer slightly acidic soil, you may want to use a fertilizer manufactured for that purpose.
Shape the plant in midsummer, cutting back any straggly growth and keep it well watered. Bring it back indoors before the first frost of autumn. Now the hard part begins. Between early November and early January, greenhouse azaleas need temperatures ranging between 40 and 50 F. (4-10 C.). A sunny, enclosed, but unheated porch will do the job so long as the temperature doesn’t drop to freezing. This is essential for growing an azalea as a houseplant, because the blooms set during this chilling time.
Give your plant enough water to keep it from wilting, but don’t be too generous and don’t fertilize. All the nutrition it needs has been stored in the leaves and fertilizing now will give you lush growth without flowers. In January, move the plant indoors, but it should still have nighttime temperatures around 60 F. (16 C.). That back bedroom that everyone complains about is ideal for this. In a few weeks, flowering should begin.
Growing an azalea houseplant and getting it to bloom again takes time and careful planning, but the reward of such lovely blooms make the effort well worth it.
How to Care for a Potted Topiary Azalea
Some varieties of azalea (Rhododendron spp.) are sold in pots as braided azalea trees. As the description suggests, the stems of these plants are braided and feature a compact cluster of flowers, giving them the look of a topiary. Azalea tree care will depend on the species of azalea and whether you are keeping the plant indoors or outdoors. Most azaleas are considered hardy only in U.S. Department of Agriculture zones 7 to 9.
A Fruitful Discussion
Azaleas have been a southern favorite for years. In the Old South azaleas graced plantation houses with their charm, provided flowers for corsages, and were the backbone of many landscape plantings. The taller Indica azaleas worked well to hide the less attractive foundations of homes. The plants grew so large they even supplied a hideaway for children to play under their leaves. They were a part of Southern life.
Today, newer azalea varieties multiply the plant’s usefulness. Kurume varieties will grow up to four to six-foot tall and look good under windows and in beds. Gumpo varieties are so short that they can be used almost like ground covers. Of course, these azaleas have the same preferences as older varieties. They need at least some shade and moist, but well drained soils. Their shallow roots grow best when plant shallowly, mulched heavily, and watered frequently.
While azaleas are celebrated for being on the lower end of the plant maintenance spectrum, that doesn’t mean they require no care. As with all landscape plants, some level of maintenance is needed for them to perform at a high level in the landscape, and fortunately they respond well when provided with the few inputs they need.
To start, let me encourage you to be a plant doctor and give your azaleas their annual physical in late March to early April. The first factor to consider is nutrition. As one would imagine, all living things require sustenance, so just like us, plants do not do well without the proper diet. Though they make their own energy through photosynthesis, they need sixteen different elements to be healthy. In particular, two primary plant nutrients may be lacking now.
If you guessed nitrogen, then you are right on target! Nitrogen is a primary plant nutrient responsible for the synthesis of essential plant proteins, forming good green leaf color and general plant growth. Nitrogen-starved plants can be easily be spotted by observing whether or not a plant’s older mature leaves are turning yellow. Some leaf drop may occur. If this is describing your azaleas, no need to despair. Generally, you can resuscitate the plant with a shot of 16-4-8 or a fertilizer labeled for acid-loving plants like azaleas and camellias. Treat this affliction with three tablespoons per ten square feet of bed now and again in May or July. Scatter fertilizer evenly around the plant to keep from burning roots.
Aside from nitrogen, another nutrient with which the azalea is prone to have a deficiency is the micronutrient, iron. Deficient plants will exhibit yellowing in new growth at the tips of the plant shoots. Generally, iron-deficient plants will have leaf veins that remain green while the rest of the leaf yellows. This may be harder to cure since iron deficiency can be caused by high pH soils, but an iron foliar spray or fertilizer granules applied to the soil may give the plants some relief. If there is a relapse, take a soil sample around the plant to diagnose the real reason for the malady.
In addition to some nutrition issues, azaleas may also suffer from some pests. For example, the azalea lace bug is a common pest that literally sucks the life out of azalea leaves. Look for the first signs of damage on plants in full sun or in protected areas beginning in March and continuing throughout the summer. Look for white stippling on older leaves. Turn stippled leaves over to find lace bug stages and black fecal spots. Examine lace bug eggs with a hand lens for signs of parasitism (a round hole in the top of the egg) and look for predators.
To scout for these insects, give your plants a weekly exam by knocking the branches over a white sheet of paper. Adults are 1/8 inch long. The transparent wings are held flat on the back. Their wings are lacy with two grayish-brown cross-bands connected in the middle. Nymphs are mostly black and spiny. The flask-shaped eggs are partially embedded in leaf tissue and often are covered with a black tar-like secretion. There are four generations a year. Eggs overwinter in leaf tissue. Lace bug adults and nymphs live and feed on the underside of leaves. Time insecticide applications for the presence of the first-generation nymphs.
Lastly, what about your azalea’s structure? Are they too tall and spindly or do they have dead branches and limbs in them? If you have lots of dead branches in your plants, then it is likely they have “dieback”. This malaise is due to fungi infecting the stems and plugging the plant’s arteries. Unfortunately, it is not curable. All we can do is to remove the dead limbs. Plants may recover or continue to die. Remove any dead branches by cutting the branch back to living tissue.
Before you run out to the yard with your pruners and hedging shears in hand, I want to caution you to not go into a pruning frenzy just yet. Azaleas are spring bloomers, so while it’s ok to remove any dead wood, wait to do any major pruning, such as a height reduction, until after your plants bloom. Otherwise, you’ll be pruning off the lovely blooms you’ve been waiting for all year! Once they’re done with their flower display, you should be safe to prune, just don’t wait too late in they year to get the job done so they plants will have time to recover and set new growth.
Being an azalea doctor may not pay well, but there are several excellent fringe benefits. Nursing your azaleas can be very rewarding. They will show their thanks with years of blooms and nice green foliage. The successful graduate of our azalea medical school is the one who remembers to care for one’s plants at all times of the year, not just while they are in bloom.Azalea Lace Bug (Stephanitis pyroides)
Sunlight Needs for Indoor Azalea Trees
Indoor azalea trees are far more sensitive to light than outdoor varieties, so you’ll need to keep that in mind. They do best in temperatures between 50 to 70 degrees Farheinht. In fact, higher temperatures can actually disrupt bloom times.
I will say that azalea trees are not exactly the most low-maintenance plants you can grow, but the blooms are worth the extra effort it takes to keep them looking their best.
To ensure that your plant gets the sunlight it needs, place the potted tree in an area of your home that gets exposure to indirect sunlight for at least 4 to 6 hours each day.
What do I mean by indirect sunlight? Think of an area of your home that gets bright light but is a few feet away from a window. Placing houseplants right next to windows can result in sunburn and dehydration, so choose your spot wisely.
Always remember that indoor azaleas trees can easily wilt if exposed to too much heat.
As with other indoor plants, be careful not to repot your azalea tree into a pot that is significantly larger than the one it came in.
This could shock your plant, something you want to avoid. Instead, choose a pot that is no more than 20% bigger than the pot it was purchased in.
When my mom gave me my first azalea tree, it was growing in a plastic pot. I simply transferred it into a pot that was a tad larger and more decorative.
Before transferring your plant, place a bit of potting soil at the bottom of the new pot, then fill in the sides with more soil.
Gently apply pressure to the soil with your palms to make sure that both the soil and the tree is in place.
Whether grown outdoors in the garden or enjoyed in a flower pot on the kitchen table, azalea plants must be exposed to temperatures within the range of approximately 0 to 90 degrees F. When actively growing or in flower, the temperature range certainly must be above 32 degrees F. The cooler the temperature, the slower the growth rate. Thus, if a flower display in spring is exposed to cool temperatures, such as 40 to 50 degrees F, the blooms will last longer on the plant, extending the display. If temperatures are higher, 70 to 80 degrees F, flowers will open and fade at a faster rate.
Indoor houseplant azaleas should be placed out of range of heating and air-conditioning registers so that their drying hot or cold breezes do not affect the plants. To prolong the flowering indoors, temperatures below 65 degrees F would be ideal, and keeping plants out of direct sunlight can reduce watering needs and heating of leaves and flowers.