Regional Gardening Reports :: National Gardening Association

In the Garden:
Northern California Coastal & Inland Valleys
March, 2007
Regional Report

Share |

This little rhododendron has survived on little care but much praise. (Photo by Henry Tenenbaum.)

The Invincible Rhododendron

I have just returned from a visit with my dear old mom who lives in the mountains of North Carolina. Her beautiful home is surrounded by mature rhododendrons that bloom like crazy in the spring. As a matter of fact, they grow everywhere back there; in the woods, along the highways, even through cracks in the sidewalks.

One of the things that particularly interested me was how the leaves fold up when the temperature drops below freezing. The colder it gets, the tighter the leaves fold against the stems. One morning the thermometer read 21 degrees and the leaves on the rhododendrons actually looked black. As soon as the temperature came back up, the plants revived and looked perfectly healthy. This all took place in just a matter of hours! Not a dropped bud, not even a spotted leaf.

When I think of all the tender loving care we lavish on rhododendrons here in California, I wonder if we are doing something wrong.

I booked a rhododendron expert to appear Henry's Garden a few years ago. He was going to demonstrate how to correctly plant a rhodie. I was puzzled when he gave me the list of materials he required to do the job; crushed lava rock, pumice, perlite and peat moss. There was no soil on his list. I went to the local nursery but could not find crushed lava rock, only the red-colored lumpy sort that people sometimes cover their front yards with when they no longer want to mow the lawn -- you know the stuff I mean. When I apologized for not being able to get the right stuff, he said, "No, that's exactly what we need."

The expert brought the rhododendron to be planted. It was a small plant, and, as I recall not even in bloom.

The first thing he had Henry do was to dig a HUGE hole. You could have buried a treasure chest in that darned hole, and if you watch Henry's Garden, you know that the digging is not easy! We had to use a pick to open the hard earth. I'm telling you, it was hard work!

He then filled the hole to the top with the combination of the pumice, lava rock, perlite and peat. Then, to all of our surprise, he scooped a shallow depression, set the rhododendron into the pre-filled hole and scooped some of the soil-less mix around the sides of the root ball. At least 4 inches of root ball was sitting high and dry.

Honestly, I thought this guy was putting us on, but that little rhododendron has survived. It rarely gets watered, never gets any fertilizer at all and it blooms every spring. And every year we all marvel at its success.

I recall an old article in Sunset Magazine where a fellow in Sacramento grew rhodies on a rocky hill side that was shaded by oak trees. As you know, Sacramento gets really HOT. Not wanting to water the native oaks, he set up a series of misters to humidify the rhododendrons several times throughout the day during the summer months. The humidity was perfect for the rhododendrons and the water evaporated before it ever reached the ground. The oaks were happy because they didn't get any water to their roots, and the rhodies looked spectacular!

My mom prunes her rhododendrons every few years with a chain saw when they start to grow above the windows. She takes them down at least three feet every time she does this grizzly job. The plants look horrible for a few weeks, but they come right back. My point here is this: Plant rhododendrons, they are tougher than you think.

Care to share your gardening thoughts, insights, triumphs, or disappointments with your fellow gardening enthusiasts? Join the lively discussions on our FaceBook page and receive free daily tips!


Today's site banner is by Marilyn and is called "Purple Crocus in March"