In The Garden: Wild hazel gets off to an early start
A few weeks ago, in the early days of January, the first catkins appeared on wild hazel. Normally, these are not seen until late January or early February.
For them to appear in the first week of the new year is remarkable, and even more so that they appeared while some hazel bushes still had a few of last year's leaves hanging on.
The reason for this early flowering was the exceptionally mild autumn and winter weather.
Although there have been some frosty nights and even snow in places, there have been many warm days, and plants respond quickly to rising temperatures and lengthening days.
Hazel is particularly quick out of the blocks because its catkins are formed the previous year and are ready to open as soon as conditions allow.
Hazel has evolved this strategy of early flowering because it is a plant of woodland and gets away to a good start before taller trees put out their leaves.
The catkins are like little tassels and are decorative in the way they hang down, pale marzipan yellow, some even lighter in colour.
These catkins are composed of male flowers that produce and release pollen on to the wind.
The female flowers are to be found along the same twigs and usually lower on the twig, presumably to allow the pollen to drift down on to them.
The female flowers are very tiny with red styles, just a few millimetres long, protruding and no petals.
There is no need for petals, because petals are a device to attract pollinating insects, but hazel is wind-pollinated and has no need of them.
Pollen is released like dust on warm days and the process can go on for weeks, the spread of time ensuring that enough pollen is shed for the flowers to set a crop of hazelnuts.
Hazel does not grow too large, making a large bush rather than a single-stemmed tree.
The native wild hazel is very easy to grow in any soil that is not waterlogged.
It thrives in poor dry soil, and rocky places, and makes a good shelter tree, much appreciated by wildlife.
Squirrels often eat the nuts before they are fully ripe.
There are also garden versions of hazel, such as the contorted hazel with twisting branches, although the catkins hang normally, straight down.
This form is usually grafted, and upright suckers often appear.
Filbert is a form of hazel with the nut enclosed in an elongated husk.
The purple filbert is quite popular in gardens as it gives a large bush with purple leaves.
The Turkish hazel is occasionally seen as a street tree, a role to which it is well suited because of its conical shape on a single straight stem, an elegant tree.