Home » Plants & Animals » Shade Gardening » Broad Leafed Evergreens - Rhododendrons & Azaleas

Broad Leafed Evergreens - Rhododendrons & Azaleas

© Marge Talt

If the Rhododendron is King of the broad-leafed evergreens, then the Azalea is Queen. They certainly are in my garden! When Bambi permits, they provide the only real 'riot' of bloom my garden sees. While I do have something blooming all season, there is nothing like the concentrated flower-power of the "Rhodies" and Azaleas in May. Actually, both are Rhododendrons and members of the ericaceae family like heaths and heathers. There are a number of deciduous shrubs along with the evergreens, as well as plants that bloom earlier than May and well into July, for me. There are so many species and hybrids in cultivation today that there is more than one for just about every shady garden.

These are not plants for the U.S. Great Plains states, or parts of the Midwest, because they absolutely require acid soil and they are generally hardy only to about USDA zone 5. Some have been developed for colder areas, but I have to tell you that nothing looks sadder than a Rhododendron leaf in cold weather. They droop and roll up like cigars; not at all attractive! So, if you live where winters get really cold, don't plant them by the front door.

They actually grow best in the US in the North West coast states where temperatures are cool and there is a lot of moisture; conditions very like those in which they originated. Some, like the Vireyas, are only suitable for warm climates. Many do quite well in the U.S. Eastern and Southern states, as well as southern California. They also flourish in the United Kingdom, where overplanting in the past has created somewhat of a glut in certain areas, from what I've read.

In addition to acid soil, they require the difficult combination of good drainage and consistent soil moisture. They are not heavy feeders. If you really feel yours need a boost, feed them in early spring and never later than July. Don't feed when planting, and only use fertilizers formulated for acid loving plants.

They have a shallow, fine-textured root system, so don't go mucking around stirring up the ground under them. Because of their root system, however, they are easy to move and can be planted, in my area, anytime the ground isn't frozen. Spring is best, with fall as a second choice where soil temps stay warm for a while. Mulch is essential - keep it in place all year around to help keep the soil moist and cool for them.