7 edible shrubs for improving urban biodiversity

4. Common hazel (Corylus avellana)

Which shrub was cultivated by the Romans, its nuts the star ingredient of Nutella? The hazel. Planting a native common hazel (Corylus avellana) will boost the presence of all sorts of wildlife in an urban landscape – the squirrels, particularly, will have plundered your shrub for their winter stash in the blink of an eye.

Give a hazel space and time – it starts producing nuts after about 8 years. Your patience will be rewarded with harvests of delicious homegrown hazelnuts and sculptural long flowers called catkins that add visual interest to the sleepy winter garden. With its sculptural multi-stemmed structure that widens at the top and grows up to 8 metres high, a hazel needs room to thrive. However, it’s also excellent for compact hedges, which are vital for sheltering wildlife. The hazel’s bendy branches are well suited for weaving; corkscrew branches are popular as Easter decorations. 

From winter into early spring, the deciduous hazel looks like it’s hibernating but in fact it’s in the midst of flowering season. It’s the first wild plant to flower so early, marking also the start of hay fever season. On its bare branches hang clusters of yellow male catkins, swaying gently. Nature perfected their lightweight, elongated forms to catch the wind and spread pollen to the female flowers, which resemble buds, located on the same tree. Beekeepers plant hazels to feed their honeybees that are active early in the year.

Appearing after the flowers, the toothed-edged leaves are a delicacy for caterpillars. The hazel is an important food plant for many butterflies and moths. These include the renowned Giant peacock moth and Comma butterfly, and moths with charming Dutch names such as the Hazelaaruil and Bonte beer, meaning Hazel owl and Multicoloured bear. 

Keep a close eye on the clusters of hazelnuts, which form on the female flowers after pollination, as they ripen in autumn from pale green to deep brown. The trick is to pick them not too early as they will be tasteless but not too late as chances are there’ll be none left as the squirrels, mice and birds will have beaten you to it. Forgotten hazelnuts from an animal’s stash get the chance to germinate and grow, which is another way the hazel spreads.