Earth Chestnut (Bunium bulbocastanum)
In summer produces lacy white flowers that resemble Queen Anne's Lace, and pretty foliage which would look attractive in the perennial border. The plant produces large clusters of small tubers that look like a small chestnut and have a nutty flavour some say akin to sweet potatoes when cooked.
Height: 60cm.
Grown organically at KoruKai Herb Farm, Banks Peninsula. Free from synthetic fertiliser, pesticides and herbicides.
You will receive a plant with roots and growing shoots similar to one of them in the image below.
The majority of the leaves have been pruned away to make transplanting easier on the plant.
Earth chestnut (Bunium bulbocastanum) is a herbaceous perennial plant belonging to the Apiaceae family, like carrot, parsley and fennel. Native to Europe and Western Asia, it grows naturally in meadows, fields and forest edges with well-drained soil.
Morphologically, Bunium bulbocastanum forms erect flower stems reaching 30 to 60 cm in height, with a spread of about 40 cm. When not in flower it is a low ground cover. It bears finely divided leaves, cut into narrow, linear segments, resembling those of fennel or wild carrot. This light, delicately aromatic foliage is inserted on thin, glabrous stems, very branched and upright. It is evergreen to semi-evergreen depending on the region, and can be consumed like parsley.
Flowering occurs in summer, usually between December and February, producing umbel-shaped inflorescences with a slightly downy appearance, composed of small white flowers typical of the Apiaceae family. Highly melliferous, these flowers attract numerous pollinators, including bees and butterflies, which contribute to the plant’s reproduction.
Growing Conditions
Hardy perennial that thrives in full sun to part shade. Very easy to grow and requires little care. In very sunny, dry areas it's better to choose a space with partial shade. It can be grown anywhere in New Zealand and tolerates frosts. In milder areas it will have leaves year round. In cold area it will go dormant in winter.
Planting and Management
Prepare soil by adding some compost before planting. Space plants 30 cm apart and mulch to retain moisture. Too much moisture can cause the tubercles to rot, while overly dry soil slows their development. The ideal approach is to water when the soil begins to dry on the surface, taking care not to saturate the earth.
Harvest
The most prized part of Bunium bulbocastanum is its tubercle, a swollen root rounded to slightly elongated in shape, brownish on the outside and white inside. This 1 to 2cm diameter tubercle is rich in starch and aromatic oils, giving it a sweet flavour reminiscent of chestnut, potato and hazelnut. To harvest your first earth chestnut tubers, patience is key. You’ll need to wait at least two years, or even three, before digging them up for your first harvest. Harvesting too early would result in smaller, less developed tubers. Dig the tubers in winter.
The leaves can be harvested year-round and make a great parsley substitute.
Finally, the earth chestnut produces elongated brown seeds, which ensure the reproduction of the species. These seeds, in addition to their role in dispersal, have long been used as a spice, their aroma resembling that of black cumin (Nigella sativa).
