California Hazelnut – by Vivian Mazur

CA Hazelnut photo courtesy Keir Morse

CA Hazelnut photo courtesy Keir Morse

If you have a shade garden, the California hazelnut (Corylus cornuta ssp. Californica) is a natural resident. It is widespread in woodland, particularly in moist or shaded canyons. It can be found along the Coastal Ranges in Northern California, the Siskiyous, and Sierras. If you hike this time of year, you may be rewarded with a crop of nuts unless the squirrels have beaten you to them. The name, Corylus, comes from the Greek ‘coys’, meaning helmet, which refers to the sheath around the nut. The hazelnut is in the birch family (betulaceae), related the alder. It is interesting to notice the similarities between them – from the shape of the leaf to the late winter catkins.

The hazelnut is an attractive addition to the woodland garden. It is a large (12’ – 15’), spreading, deciduous shrub with graceful, arching branches. In late winter the catkins appear. Each plant has separate male and female flowers but it is the males that are most conspicuous as they develop into long, golden tassels, followed by the unfurling of soft, velvety leaves. In late summer or early fall, the nuts ripen, much appreciated by squirrels and birds.

The California hazelnut is an adaptable garden plant. It is drought resistant once established but unlike many native plants, it will accept year-round water. It is a plant that will fend for itself, needing only pruning to keep it looking attractive. Some natural companions are sword ferns, bush monkey flower, and Douglas iris.

2 thoughts on “California Hazelnut – by Vivian Mazur

  1. one of my all-time favorites for semi-shady nooks around houses. i love the seasonal drama from new leaves, autumn color, and the catkins! i love the way the leaves are held w/ equal spacing throughout and at peculiar angles to maximize photosynthesis in low-light conditions. i often find them growing near coffeeberries and red elderberries. it makes a very nice shrub for entryways.

  2. Hazelnut supports the caterpillars of a great many moth species. Listed below are moth species known from California recorded as employing it as a hostplant:

    Saturniidae: Polyphemus Moth (Antheraea polyphemus).

    Drepanidae: Tufted Thyatirid Moth (Pseudothyatira cymatophoroides).

    Geometridae: Pale Beauty (Campaea perlata), Orange-marked Hazelnut Moth (Dysstroma ochrofuscaria), Linden Looper (Erannis tiliaria). Mottled Euchlaena (Euchlaena tigrinaria). Northwest Phoenix (Eulithis xylina).
    Hesperumia latipennis. Sulphur Wave (Hesperumia sulphuraria). July Highflier (Hydriomena furcata). Western White Ribboned Carpet (Mesoleuca gratula) – an early spring day-flying species. Brown-lined Looper (Neoalcis californiaria). Rindge’s Pero (Pero mizon). American Barred Umber Moth (Plagodis pulveraria occiduaria).

    Lasiocampidae: Western Tent Caterpillar (Malacosoma californica).

    Lymantriidae: Variable Tussock Moth (Dasychira vagans).

    Noctuidae: Charred Dagger (Acronicta brumosa). Corylus Dagger (Acronicta falcula). Copper Underwing (Amphipyra pyramidoides). Rusty Shoulder Knot (Aseptis binotata). American Dun-bar (Cosmia calami). Diarsia esurialis. Egira hiemalis. Lacinipolia pensilis. Nameless Pinion (Lithophane innominata). Speckled Green Cutworm (Orthosia hibisci). Brown Angle Shades (Phlogophora periculosa). Pseudorthodes irrorata. Otter Spiramater (Spiramater lutra). Colorful Zale (Zale minerea).

    Notodontidae: Angle-lined Prominent (Clostera inclusa).

    Tortricidae: Acleris cervinana (likely; moth found in California, eats “Corylus sp.” in Canada). Ugly-nest Caterpillar (Archips cerasivorana) also said to eat “Corylus sp.” in Canada. Large Aspen Tortrix (Choristoneura conflictana). Oblique-banded Leafroller (Choristoneura rosaceana). Filbertworm (Cydia latiferreana). Birch Leafroller (Epinotia solandriana). Three-lined Leafroller (Pandemis limitata). Poplar Leafroller (Pseudosciaphila duplex, Canada).

    Likely specimens getting more sun are most attractive to insects.

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