This is a subscriber-only article
Azaleas are beautiful flowers.The botanical names start with rhododendron, which translates as ‘red tree’, a reference to the flower colour of many species. Many of the rhododendrons that are grown in gardens are evergreen. The naming has also become a bit confused because of the use of the name azalea as the correct name for the deciduous species before the botanists thought best to include them with rhododendron.
The deciduous azaleas share the same parentage of related species, all about two metres with deciduous habit and similar flowers. These include Rhododendron molle, from China, which used to be Azalea mollis with yellow or orange broad funnel flowers; Rhododendron japonicum from Japan, with orange to red flowers; Rhododendron luteum from eastern Europe with yellow scented flowers, somewhat tubular; and Rhododendron occidentale, from North America, with white or pinkish flowers and good scent.
There are hundreds of named azalea cultivars, and many sold just as ‘Azalea mollis’. These can be raised from seeds, and the named varieties are reliable. ‘Golden Flare’ is a lovely yellow to deep ochre colour; ‘Balzac’ is a strong red; ‘Christopher Wren’ is orange-yellow; ‘Homebush’ is rose red; ‘Strawberry Ice’ is a pretty pale red; ‘Klondyke’ is golden-yellow; ‘and Gibraltar’ is orange-red. So there are many to choose from and they are best chosen in flower, which is now.
Garden value
The deciduous azaleas have a very different colour range to most rhododendrons. While many evergreen rhododendrons have red, purplish and pink flowers, the deciduous azaleas tend to be more yellow and are generally very bright and vivid. The colours are a delight — blazing hot red, candy pink, yellow, flame orange, marmalade and salmon. Even though the colours vary greatly, they seem to blend with each other easily, often heightening the effect of the others.
Being deciduous, they have new leaves that emerge at the same time as the flowers and just afterwards. The leaves have lovely fresh shades of bronze, copper and apple green, varying with the colour of the flowers, dark for red colours, bronze for orange and green for yellow.
They also have the bonus of autumn colour by contrast with the evergreen rhododendrons which do not change. Deciduous species are in general less prone to frost damage.
This group of azaleas also show good autumn colour in the same foliage that is so pretty in springtime. The varieties that show strong red and orange colours of flower and dark foliage in spring also show good rich colour in autumn. The lighter colours of yellow and pink tend to show similar colours in their autumn shading.
Growing deciduous azaleas
The deciduous azalea group has broadly the same needs as the rhododendrons. This means they like acidic soil, well drained but capable of holding moisture in summer and well supplied with humus. They also benefit from reasonably good shelter and plenty of sunshine, but not in dry soil.
Although they flower best in full sunshine, they are happy in some light shade, but not so in constant shade. Sunshine part of the day or light shade is satisfactory.
They do not like to have the competition of big tree roots underneath as it is too dry.
The red campion is a native flower which also has the name ‘catchfly’ because of the sticky flower stems that trap small insects. It is seen by roadsides in the east mainly. The wild plant has flowers spread along the stems.
The garden form, which is named Silene dioica ‘Rollie’s Favourite’ has dense rosettes of hairy broad leaves at ground level and in early summer, relatively short flower stems which rise to about knee-height above the leaves. It was a popular flower in old-fashioned cottage gardens and it is still widely seen in the gardens of rural houses as the plant is often split up and re-planted. The garden form is more common in the West.
There is a white wild campion that is found in the centre of the country. When the two wild species cross, the offspring appear with pale pink flowers. There is a double-flowered form of the garden red campion. While the red campion is easy to grow, it can also die out quite suddenly. This is usually caused by a very heavy infestation of greenflies in early summer on the backs of the older leaves down in the rosettes. These can build up and draw all the sap out of the plant. It is worth checking to make sure that greenflies are not proliferating. The plants are kept vigorous by dividing them every few years to re-invigorate them.
Flowers
It will soon be time to plant up containers, especially in the milder areas. Assess the stock of pots you have, buy more if necessary, and compost, and plan the planting scheme. As spring flowers fade on bulbs, resist the temptation to cut away the foliage; it is important that the leaves be allowed to die back.
Lawns
Most lawns have grown strongly in recent weeks, likely driven by the plentiful supply of water on all but the most sandy soils.
Another factor, not often taken into account, is the decay of organic material naturally present in the soil. This can deliver sizeable quantities of natural nitrate.
Fruit, vegetables and herbs
The sowing of vegetable seeds was much delayed by the very poor soil conditions that made it very difficult to make a good tilth. But vegetable seedlings can progress rapidly this late in the season. The first flush of weeds is always the worst but if it is controlled, it will be easy to stay ahead.
Trees, shrubs and roses
All young trees should be checked for water deficiency. Drought can occur even with plenty of rain. Watch for small leaves and slow growth. Check also for wind-rocking and staking. Control weeds and grass at the base — young trees need to be weed-free without competition.
Greenhouse
Ensure that all bedding plants and tender vegetables for planting out at the end of May are growing well. Keep up watering and feed occasionally. Space the pots adequately to ensure proper development.
If possible, plant out tomatoes now in the greenhouse. And don’t forget to check for pests.
SHARING OPTIONS: