There are more than 7,000 trees in Alexandra Park and resident expert, Stephen Middleton from The Friends of Alexandra Park, is introducing us to them one by one!
“Goodly to look on but for little else.“ An unkind quote by English writer John Evelyn over four hundred years ago.
Make your way to the Grove in the westernmost part of the park and find the two 2012 London Olympic sculptures and next to them is our Tree of the Month, the Turkey Oak (Quercus cerris).
The Turkey oak is not native to England, but has been planted since the early 1700s. It was enthusiastically adopted as it produced hard wood like other oaks and it grows more quickly reaching a typical maximum height of 30 metres in this country. Unfortunately the wood is not as useful as was hoped with the timber liable to split or crack.
This tree is naturalised (reproduces freely in the wild) in southern England. In some areas it can outcompete our native oaks growing faster and not as susceptible to mildew as our own species.
Like our native oaks it is deciduous (loses its leaves in winter) and has clusters of buds at the ends of twigs. The leaves are quite variable with the lobes sometimes pointed and sometimes rounded. Our tree of the month can be identified by the roughness of its leaves and the long twisted whiskers by the buds. The acorns take about a year and a half to develop and are unusual with the outside being covered in scales giving it a mossy look.
This is a good tree to plant if you want a quite fast growing ornamental oak. It has the added advantage that it can tolerate growing on a chalky soil and in polluted air.
On the other hand the prevalence of this tree has led to the spread of knopper galls (distorted acorns) on our English and sessile oaks. The culprit is a small wasp which has a complicated life cycle with one part on the catkins of the Turkey oak and other part producing deformed acorns on our native oaks. So if you remove Turkey oaks, you will eradicate the knopper galls.
From here, for comparison, you can also admire a huge English oak just across the path in a fenced enclosure which was our tree of the month two years ago.
Want to know more about trees, there will be a Friends of Alexandra Park beginners tree walk on Sunday, 11th August.