For me, nothing is more emblematic of a Northwest garden than the rhododendron.
Well, except for maybe stinging nettles and Himalayan blackberries. But for now, let’s put those two out of our minds and think only happy thoughts, shall we?
The rhodie is a highly hybridized member of the Ericaceae, or heath, plant family that is particularly well-suited to our maritime climate and our naturally acidic soils.
In fact, there is a native species of rhododendron found along the western seaboard from British Columbia to California, Rhododendron macrophyllum, which just so happens to be our state flower.
With so many other Ericaceae species nearby, like the Pacific madrona, red and evergreen huckleberries and salal, it’s in very good company
It’s the flower that seals the deal for me. What’s not to like about pompoms of strikingly vivid reds, pinks, purples and more, that are just about as big as your head? And better yet, rhodies aren’t that hard to grow or care for.
First of all, start with the soil. You’ll want a well-drained, richly organic soil with a pH of 4.5 to 6.0 for optimum health. If you’re planting your rhodie in native soil, this shouldn’t be a problem.
If you’re planting it in soil you know has been amended to make it more alkaline, then add pine needles or oak leaves to up the acidity level.
Planting too close to new concrete can also pose a problem because of the lime leaching into the soil.
The same goes for actually planting in limestone or in seashells.
Lavender and other alkaline-loving plants might go for seashell mulch, but skip it with rhodies.
Once established, rhodies can survive on rain alone, but do give them a drink once or twice a week during dry periods in their first year, just as you would any other new shrub.
If it makes you feel better to fertilize them, go ahead, but know rhodies don’t really need it once they’re on their way.
This isn’t to say they may never need some supplements in their diet.
If the leaves of your rhododendron turn yellow between their dark green veins, this is called chlorosis and is a symptom of iron or magnesium deficiency. If it’s a lack of magnesium you will also get red spots on the leaves.
You can treat the iron deficiency with a foliar spray of iron sulfate, but first check your soil’s pH.
Most cases of iron or magnesium deficiency are caused by the soil being too alkaline to allow the plant to take up minerals. You may just need to lower the pH.
Some cultivars like the sun and some cultivars like the shade. Find out before you dig that hole which it is.
A shade-loving plant will burn in the sun and a sun-loving plant might fail to bloom in the shade. Rhodies have shallow roots, so moving them isn’t as horrendous as, say, trying to move a well-established stand of Oregon grape. (Don’t go there. Ever.) But the person you hand the shovel to may balk just the same.
To deadhead or not to deadhead? If you never deadhead your rhodies, don’t beat yourself up. They’ll still produce flowers year after year.
They may not be as lush or look as well-groomed, but if deadheading them means you have to risk life and limb up on a ladder, just let it go.
Or give the job to the guy you tried to give the shovel to.