by Dave Waltzer
Azaleas are sometimes called “the royalty of the garden” and can be a great choice for your garden, particularly in a shady or sun dappled area.
Azaleas, which belong to the genus Rhododendron, are divided into two different types, deciduous and evergreen. There is a species that grows wild in the Santa Cruz Mountains, Rhododendron occidentale. These native azaleas are considered to be deciduous and have fragrant blossoms.
An established azalea in full bloom can be one of the most spectacular features in the garden but require some special attention when planting. Soil composition, pH, and appropriate light are all key components to be considered when growing azaleas.
Azalea roots like to be moist, but not soaking wet. In other words they like well draining soil that is rich in organic matter. If your soil is particularly hard and does not drain well it is recommended that you mound up some rich, well-drained soil and plant in the raised areas. The amount of organic matter in your soil is crucial to the health of your azalea because organic matter retains moisture much better than sand or mineral soil. Those who live in the sand hills of Scotts Valley, Ben Lomond or Felton should take note… you will need to use a great deal of soil amendments if you want to grow azaleas. Commonly used soil amendments that help retain moisture are coarse sphagnum peat moss, fir bark, sawdust, gorilla hair or composted garden scraps.
Soil pH is also important. Proper pH is essential to a plants’ ability to utilize essential minerals within the soil. Simple inexpensive soil test kits can be purchased at most nurseries. The optimum soil pH for azaleas is between 4.5 and 5.5. Soil ph ranges from acid to alkaline. The lower the pH number, the higher the acidity of the soil. If one wishes to “raise” the pH of the soil, the acidity of the soil is increased and the actual number becomes lower. I realize that this may be a little confusing.
If the pH of the soil is incorrect, important minerals become insoluble and consequently unavailable to the plant. Yellowing leaves are a common ailment found in unhealthy azaleas and this is usually an indicator of an iron deficiency. Since iron is crucial to the production of chlorophyll (which causes leaves to turn green) a good way to green up your plant is to add some liquid iron. Another solution is to add sulphur to the soil. Both of these ingredients can be readily purchased at many nurseries. It is important to follow the directions on the bottle because indiscriminate applications can result in overdose, and possibly death to the plant.
Many areas in and around Santa Cruz contain large quantities of limestone in the soil and limestone is highly alkaline, which azaleas do not like. The solution to this problem is the same as that given above to improve moisture retention and improve drainage. Mound up soil rich in compost or organic matter, and plant in those mounds.
The most frequently encountered azaleas are those found in the supermarket wrapped in pretty aluminum foil-paper with lustrous dark leaves and plump pink buds. Husbands hurrying home to their wives, who are mad at them, often purchase these azaleas as last-minute gifts. These azaleas commonly live indoors for a couple of weeks until they are finished blooming, then are moved outside where they frequently perish from over-watering, under-watering, or improper soil pH. Azaleas purchased from supermarkets and/or florists have been subjected to heavy fertilization, which causes the plant to become more sensitive to improper soil pH. Therefore, if you are the recipient of one of these florist azaleas from a loved one, you will need to be especially diligent if you want to ensure its long-term survival.
Light is an important factor to consider when choosing a good location in your garden to plant azaleas. Generally one can grow azaleas in full sun along the coastal areas of Santa Cruz, but up in the mountains where the temperature is a good deal warmer, it is best to keep azaleas out of the afternoon sun. Areas of dappled sunlight are also good locations. If you live in a redwood forest with a dense canopy, do not be surprised if your azaleas don’t set many blooms. Most varieties need at least some sunlight to set buds. Deciduous azaleas seem to be better at taking full sun even in inland areas as long as they have adequate moisture.
Even if you are not into growing azaleas, you can still enjoy their splendor in the wild. Rhododendron occidentale, the deciduous native azalea, can be found growing in the Santa Cruz mountains and throughout California, Oregon and Washington. Interestingly, in his great novel, East of Eden, John Steinbeck describes an excursion into the hills to see the native azaleas in bloom.
Recently at a meeting of the Monterey Bay Chapter of the American Rhododendron Society, Mike McCullough gave a slide show about native azaleas. Mike has traveled throughout California, hiking up and down mountains to seek out, map and identify hundreds of different variations of the native azalea. The colors, shape, and size of the flowers vary significantly within this species. Native azaleas are usually found growing in areas where there is year round moisture, near springs and seeps. They bloom in May and June. Native azaleas can most easily be spotted growing around the visitors’ center at Big Basin Sate Park, or along the Eagle Creek trail in Henry Cowell.
Native azaleas are difficult to find in nurseries, but several deciduous species, most of which are deliciously fragrant, can be purchased either locally,online through mail order.
David Walzer is a landscape contractor and designer in the Santa Cruz area and can reached at (831) 252-0121.