Tree spotlight no. 4 – The Crab Apple

 

Malus-sylvestris-Native-Crab-Apple-Ireland

Crann fia-úll (Malus sylvestris)

Like the wild cherry, crab apple has been deliberately grown around old farmsteads (and the fruit used for crab apple jelly) but is also a truly native species found in old woodland. Crab apple is found in hedgerows throughout the Irish countryside. Unlike modern hybrid apples, crab apples grow true from the apple pips.


It is a small tree, very suitable for gardens. It bears attractive pink/white apple blossom in the spring, while the apples provide an autumn feature in the garden, as well as a useful crop.

crab apple tree in the middle of a large green field

What does crab apple look like?

Overview: one of the ancestors of the cultivated apple (of which there are more than 6,000 varieties), it can live to up to 100 years. Mature trees grow to around 10m in height. They have an irregular, rounded shape and a wide, spreading canopy. With greyish brown, flecked bark, trees can become quite gnarled and twisted, especially when exposed, and the twigs often develop spines. This ‘crabbed’ appearance may have influenced its common name, ‘crab apple’.

The crab apple is one of the few host trees to the parasitic mistletoe, Viscum album, and trees are often covered in lichens.

Leaves: the brown and pointed leaf buds form on short stalks, and have downy hair on their tips, followed by glossy, oval leaves, which grow to a length of 6cm and have rounded triangular teeth.

Flowers: in spring, the sweetly scented blossom is pollinated by bees and other insects, which develops into small, yellow-green apple-like fruits, around 2-3cm across.

Fruits: sometimes the fruits are flushed with red or white spots when ripe. Birds and mammals eat the fruit and disperse the seeds.

Look out for: it has a ‘crabbed’ or spiny appearance because of gnarled and twisted twigs.

Where to find crab apple

Crab apple thrives best in heavy, moist, well-drained soil and areas of scrub. They grow throughout Europe.

Value to wildlife

The leaves are food for the caterpillars of many moths, including the eyed hawk-moth, green pug, Chinese character and pale tussock. The flowers provide an important source of early pollen and nectar for insects, particularly bees, and the fruit is eaten by birds, including blackbirds, thrushes and crows. Mammals, including mice, voles, foxes and badgers also eat crab apple fruit.

CrabApples_large

How we use apple

The trees are often planted in commercial orchards as their long flowering period makes them excellent pollination partners for cultivated apples. The fruit can be roasted and served with meat or added to ales or punches. More commonly it is used to make crab apple jelly, and also as a natural source of pectin, for setting jams.

The pinkish wood has an even texture and makes good quality timber, and lends itself particularly well to carving and turning. It also makes a sweetly scented firewood. In Ireland a yellow dye was extracted from the bark to colour wool.

crab-apple-bark-2-lo-res

Threats

The crab apple is susceptible to a variety of fungal infections, including apple scab, honey fungus and apple canker.  As you can see above the Crab Apple tree in the Rose Garden in Trinity College Dublin suffers from apple canker, the white furry residue on the bark.