Entranced by photos I'd seen of the 3 to 5-inch opulent blooms of Japanese camellias (Camellia japonica), I tried growing a plant indoors years ago, as few camellias will survive outdoors north of zone 6. I found, however, that our household temperatures just weren’t low enough to suit the plant. Although it grew amiably enough, it never flowered during the winter, as it is supposed to.
Our rickety back room has since become very chilly during the coldest months, however, so I think I might now be able to successfully grow camellias there. In preparation, I’ve been reading up on how that is done.
In the process, I learned that the autumn camellia (Camellia sasanqua) might be the best choice for northern gardeners, since it can flower early—shortly after potted plants are moved indoors for the winter. It reportedly also tolerates heat and sunlight better than the Japanese type, and is more likely to be scented.
On the down side, sasanqua flowers tend to be smaller than the C. japonica type, only 2 to 3 inches in diameter, and usually only single to semi-double rather than fully double. In The Essence of Paradise, Tovah Martin recommends 'Fragrant Pink', which she reports has 2-inch pink flowers and smells sugary--like cake frosting.
Just for fun, you might also want to try the tea plant (Camellia sinensis), which has single white flowers with pompom yellow centers. I wouldn't try harvesting its leaves for your daily cup, though, or you could end up with a pathetically naked plant.
Growing any camellias indoors still will be difficult for those of us who don’t have a cool greenhouse, but I enjoy a challenge. If you too would like to try this, bring the potted plants indoors in autumn when daytime temperatures have fallen into the 50s Fahrenheit and nighttime ones are dipping close to freezing.
Choose an airy location for the camellias, such as a minimally heated sun porch, garage, or breezeway, where temperatures drop to between 35 and 55 degrees at night and don’t rise above 70 degrees in the daytime. Give the plants partial sun, such as an east or west-facing window or a grow-light . Water them with rain or spring water, if possible, as hard tap water may raise their soil pH. You also want a high level of humidity, but I've found that chilly rooms naturally retain more of that than heated ones do.
Prune or repot the camellias only in late winter or early spring just after they have finished blooming. To help prevent root rot, place them in clay pots filled with an acidic fast-draining potting mix, and try to keep that soil's pH between 4.8 and 5.8.
Early spring also is when camellias should be fertilized, since you want them to grow as much as possible before they start setting buds in early summer. The people at Logee’s suggest that you add 1/2 inch of cottonseed meal to the surface of the soil in each pot to provide slow release feeding. They also recommend that you treat the camellias with Epsom salts twice a year by adding 1 tablespoon of those salts to 1 gallon of water and watering the plants with the solution.
During summer, move them outdoors to a location in bright shade or only partial sunlight, and make sure that their soil remains evenly moist. Once buds form, pinch off all but one bud in each cluster if you want large blooms.
Mark, on the sides of the camellias' pots, which side is facing in which direction. You want to keep the plants facing in the same direction once they are brought inside, or they are liable to shed their buds in protest over the change.
Granted, those buds may blast anyway, but you don't want to give them a good excuse to do so! If you follow all these rules, you may or may not actually get flowers, but you will have another kind of blast trying!
Photos: The cropped and enhanced public domain camellias photo in the banner is by Dr. Bernd Gross, courtesy of Wikimedia Commons. The Camellia sinensis photo is by genesnsy and the Camellia 'Fragrant Pink' photo by violabird, both from the Dave's Garden PlantFiles. The antique image of Camellia 'Princesse Clotilde' is from the 1845 Flore des Serres et des Jardin de L'Europe (Flora of European Greenhouses and Gardens) by L. Van Houtte, courtesy of plantillustrations.com.