QBARS - v20n1 Liming Rhododendrons

Liming Rhododendrons
Alleyne R. Cook, Vancouver. B. C.

Rhododendron ponticum that received 12 heaped double handsfuls of lime.
Fig. 14. Rhododendron ponticum that received 12 heaped double handfuls
of lime. It is in excellent health.
Alleyne Cook Photo

Poor Performing Rhododendron
Fig. 15. Rhododendron ponticum in the same border as the limed plant.
This one is dead.  It received no lime.  Picture taken 1963.
Alleyne Cook Photo

Dr. Phetteplace after reading my first article (A.R.S. Bulletin, Apr. 1962, pp. 101-106) on liming rhododendrons wrote an article suggesting that a further report might be in order. Nearly four more years have passed, making it at least 7 years since lime was applied to any of those examples before mentioned. I feel that if there were to be any deaths or illnesses they would have occurred before now.
Unfortunately they have not; not a single plant that I have been able to keep track of. As several hundred were in Mr. Living's nursery, (Example 4) to which 7 tons per acre had been applied, there may have been losses after they disappeared into private gardens. As they had grown from cuttings to saleable plants in the limed ground with nothing but beneficial results from the lime, I tend to think it unlikely any would have died. However it is a possibility that should not be overlooked.
Example 8, all three bushes are now in perfect health.
Example 6. In this, two bushes were growing in the same border. One was given 12 piled double handfuls of lime. The second was given nothing. In the spring of 1963 the limed plant had 211 trusses and as will be seen from the photograph was well budded for 1964. It is still a healthy bush. And the bush that received no lime? It is dead. It died in the summer of 1964 after being a sick bush for a year. The photograph taken in the fall of 1963 shows bare stems, a ground littered with dead leaves and poor growth.
To all the examples in the first article must be added all the lime haters of my own garden, yet none of these have shown any adverse effects from several dressings.
However, I agree with Dr. Phetteplace when he advocates proceeding with caution. Even though I can find no reason for my being correct when all experts maintain the opposite opinion there may be a slight possibility that in some districts my methods might not succeed.
I still believe that there is no substitute for the proper preparation of a garden. Deep digging with the inclusion of plenty of humus before anything is planted, will give all plants the necessary nutriments. How seldom does this happen. If the preparation has been poor and the plants appear to need feeding it does not mean that the essential elements are not already in the soil. They probably are, but are not available. That is what lime does - it makes the plant food already in the soil available to the rhododendrons so that they can thrive. This is what must have happened to the healthy rhododendron in the above photograph.