In a part of my garden that most plants find a trifle too shady grow two azaleas that are coming into full flower this weekend. Their leaves are a rich, dark green, darker than the shade they grow in, and the pure-white flowers look like wet snow on the branches. They are so white that all other white flowers in the vicinity look like thickened cream. Appropriately, they are named Alaska.
Why single out a white azalea when so many colorful flowers are bursting into bloom all over town now? Simply because Alaska is my favorite azalea and too good a plant to keep a secret.
I am not alone in this regard. Many landscape architects and designers have also discovered Alaska. It is perhaps the one sure-fire azalea in Southern California. Not that others can't be grown--beautifully--but Alaska almost can't fail, and if you've had difficulty growing azaleas, this variety might restore your confidence.
Cool Toward the Sun
What azaleas want is a woodsy soil and a little shade, despite the name of sun azalea that has been attached to some. There are azaleas that will grow in full sun, and they tend to flower profusely, but they would be better called sun tolerant because that is what they do--they tolerate the sun but show their dislike by always being a little yellowish in foliage.
These sun-tolerant azaleas mostly belong to a group of hybrids called Southern indica azaleas, a group selected from the other large group of hybrids called Belgian indica hybrids, of which Alaska is a member. The Belgian indicas prefer part shade; the Southern indicas were selected for their sun tolerance.
What any azalea does not like is heat, so they should never be planted against a south- or west-facing wall that might reflect heat, and should always be planted in the cooler pockets of the garden. You can find these cool spots at this time of the year by just walking around the garden in the early morning.
They also don't like the heavy clay soils so typical to Southern California. Some gardeners have taken to growing them in totally artificial soils made of the specially treated sawdust and ground bark sold at nurseries, often mixed with peat moss. The native soil is completely excavated to a depth of a foot and the artificial soil put in its place.
Soil Drainage Is Vital
Almost all successful plantings are also in soil that is at least slightly mounded above the normal ground level. The reason for both measures is to facilitate drainage--so excess water passes by the roots into the subsoil and does not sit, making the soil soggy. This is necessary because azaleas need a lot of water, so it is all too easy to overwater them while trying to provide enough. Excellent drainage takes care of the excess.
Azaleas are best watered from overhead with sprinklers, but while they are in flower try to water at a time of the day when flowers will quickly dry--just before they are bathed in sunlight, for instance. Or water by soaking the ground around them. This change of routine is necessary because the flowers are likely to turn to mush if they stay wet for a few hours.
Back to soil composition. You cannot plant them in a totally artificial soil and then walk away, because such soil dries out very fast. For this reason, I prefer adding the specially treated sawdust and peat moss to the existing soil, digging deep with a spade and then mixing it all in, by hand if need be, until it has a fluffy, almost meringue-like consistency. About half real soil and half amendments is my recipe. Also, because I have added so much to the soil, it is naturally mounded higher.
Azaleas do most of their growing as they flower or soon after, so they can be planted while in flower. This works out nicely because then you can buy them in blossom and know just what you're getting. And this could be said to be a necessity if you are picky when it comes to colors, since most of the azaleas sold in Southern California have flowers that are unusually colored, in the sense that they're not pure shades of any color. The pinks are salmony, the lavenders on the magenta side and so on, so combining them with other flowers is tricky business, one reason the chaste Alaska is so popular, and so foolproof.