Trees arrayed in all their autumnal beauty
Turning leaves are putting on a good show this year, writes Gerry Daly
There is quite a good show of colour in the garden this autumn, just as there has been for a few years. The weather influences the autumn colour show dramatically.
First, a good sunny summer is needed to build up the sugars in the trees. This allows a slow transition to autumn as the deciduous trees withdraw the valuable chlorophyll, which is the green pigment in plants that traps the sun's energy. It contains the plant nutrients, iron, sulphur and nitrogen, all relatively unavailable to plants and to be conserved. Sunny warm days and chilly, but not hard frost, is the best for colour.
As the green pigment is flushed back into buds, bark and roots, the hidden pigments are revealed. Anthocyanins are red and purple pigments, while xanthophylls and flavonoids are yellow. These are not as soluble as chlorophyll and remain behind, colouring the leaves, and the same pigments colour fruits and berries.
The longer the leaves last, the more colour is expressed. A notable feature of poor colour years is that leaves fall while still green. The absence of strong winds is also needed.
The soil has an influence. Acidic soil heightens the colour of the pigments, while dry soil tends to reduce vigour but concentrate growth. The famous New England Fall is due to a hot summer, warm autumn days with cool nights, and the soils are impoverished and acidic.
Many gardens have plants that show autumn colour - but in most cases these were not expressly planted with that in mind. For instance, many flowering cherry trees have good autumn colour, notably Prunus sargentii - one of the first to colour. Hornbeam, birch and beech also colour well, although rarely planted with that purpose in mind.
As few as one or two autumn colour specials can be enough to light up the garden for a few weeks at this time of year.
For instance, almost any kind of maple will brighten the garden, especially the Japanese maples and the snakebark maples. The larger red maple can be stunning in bright crimson colour. The sweet gum, Liquidambar styraciflua, is not always brilliant but when it gets a good sunny year, it is superb in shades of yellow, red and purple, and this is more likely to occur on well-drained soil. Dry soil also suits staghorn sumach which colours better on poor than on good fertile soil.
The Juneberry or Amelanchier is an excellent autumn colour shrub or small tree. It flowers in spring and changes to lovely shades of red and yellow, lasting a long time in good weather. The Chinese spindle, Euonymus alatus, is a small tree or large bush that colours to beautiful shades of red, pink and yellow.
On a large scale, the tulip tree, Liriodendron tulipifera, often provides bright yellow colour with a greenish-lemon tinge. Many dogwoods, both shrub-sized species and trees, are superb. Parrotia is a wonderful autumn tree, quite a broad tree as it ages, with stained-glass quality autumn colour.
Much of the success of planting specially for autumn colour depends on how well the trees and shrubs are located. Groups of plants with varied colours can be charming, but if they are grouped together in the one area, the rest of the garden can appear dull by comparison.
If the evening sun, or morning sun, catches a plant, the effect of its colour can be greatly enhanced - especially for plants such as magnolias, maples and cornus that are handsome year-round.
Autumn colour foliage reflected in water has its value doubled, and it is often the case that there are calm spells in autumn when the surface of ponds is mirror-like. On a nice sunny autumn day, assess the level of autumn colour and plant more if needed.
GO BACK IN TIME
If you're looking for an outing this weekend, take a trip to Duckett's Grove, the 18th, 19th and early 20th century home of the Duckett family. It was at the centre of an extensive estate for over 300 years and the principal seat of one of the most prominent families in Carlow. Now in ruins, it still remains a powerful reminder of an earlier period, the gardens have been restored and are a treat for visitors; carlowtourism.com
The Italianate Gardens of Westport House lie in what is now known as the West Lawns - and they are being painstakingly restored so that they can dazzle visitors once more. The gardens were originally created in 1915 as an important element of the Italianate Terraces, allowing the house's residents and visitors to 'take the air' in a refined fashion. Now you can too; westporthouse.ie
GO PLANT HUNTING
How did the staghorn sumac get its common name? You can probably see that, particularly in winter, the heavy upward branches resemble a deer's antlers. It makes large divided leaves that are coloured well these days, and it colours on dryish soil that is not too rich. It suckers a bit - but unwanted ones are easily chopped away.