In my last article I focused on Azaleas which make up a major part of the Rhododendron family. However, I wouldn’t want to do a disservice to the familiar evergreen rhododendrons by missing them out; especially now.
As we pass into June you might have thought that you could forget about all of those spring flowered shrubs that were such stalwarts in March, April and May. Surely they have done their duty of cheering us up during bad weather and can now fade gracefully into the background? By and large you could be forgiven for making this assumption but a little tender loving care now and you will reap the rewards when next year rolls around. This is because these plants will produce next years flowers on wood that is grown and ripened over the coming summer.
Though we enjoy the flowers they are a difficult and expensive exercise in reproductive advertising for the plant and it will need to recoup a lot of lost energy if it is to set a sufficiently healthy crop of flower buds. Feeding, if not already started, should be done from now until the end of July. After July this should cease so that the plants have time to harden up the new growth, which can be floppy and tender, before winter. I feed my plants in three main ways. Firstly, I apply a good scattering of a general purpose, organic fertiliser such as blood, fish and bone around the roots. This provides a steady release of nutrients over the long term. I prefer to stay away from pelleted chicken manure which can act a bit like rocket fuel and is useful where demand is more intense. Secondly, I allow fallen leaves to collect and decompose around the plant. Rhododendrons and other calcifuge plants often take up more trace elements than they can use and store them in the foliage. These are then re-released when the leaves break down underneath the plant. I supplement this diet with plenty of leaf mould which improves the condition of the soil around the plants and helps to keep the roots moist during summer drought.
Thirdly I give all of my plants a copious liquid feed on a weekly basis. If you only have one or two plants in the garden or in pots then this can be done by drenching the roots from a watering can or hose with a feeder attached. However, if you have a large number of plants then spraying on a foliage feed works wonders as the food is rapidly absorbed. Do this when there is no direct sunlight falling on the plants so that they wont scorch. Early morning, evening or a dull day are best. I use concentrated liquid seaweed diluted with water which also does wonders for other plants. I have used it to pep up my yew hedging for example. You can also buy calcified seaweed in granular form as a general soil improver and it has my own seal of approval. Scatter it on the surface or lightly fork it in and it will help to improve the overall health and structure of the soil.
With these few tips in mind why not try a rhododendron in your own garden? The name means tree rose and some do grow to the size of small trees with interesting bark and foliage to match. However these monsters require more specialised growing conditions as well as large helpings of patience! For the average garden there is a huge choice available. R. ‘Percy Wiseman’ makes a good choice for most gardens as it is easy to grow and the pink flowers with a pale apricot centre are thoroughly charming. By contrast R. niveum has bright purple trusses which stand out wherever they are. One of the easiest to grow and tolerant of even a neutral soil is the Japanese R. yakushimanum which has small tough leaves and bright pink or white flowers. There are even many dwarf cultivars that you can chose from if space is limited!
You don’t have to be an expert. Just follow the simple steps above for a fantastic spring display.