Bupleurum rotundifolium 'Griffithii'

This wonderfully intriguing annual makes a great companion plant for showier flowers in the garden or the vase, the blooms of chartreuse green bring out the colours of other flowers, especially bright ones. In “The Bold & Brilliant Garden” Sarah Raven says Bupleurum is one of her "favorite plants for threading right through blocks of intense colour".

Bupleurum produces a single main stem that branches heavily toward the tips, with beautiful blue-green, eucalyptus-like foliage, the stems come through the leaves at alternating angles. The sprays of yellow-green flowers are compound umbels, which look like an airy euphorbia, though the plant is more closely related to dill, fennel, and other umbellifers.

Easily grown from seed, it is a particularly unique dried or cut flower. A perfect filler flower that adds colour and shape to flower arrangements and useful for adding an unusual touch to mixed bouquets.
Bupleurum is a very large genus of plants of the Apiaceae (umbellifer) family, represented by 185 to 195 species. While not a completely new plant to cultivation, this interesting but sadly underused flower is currently being heavily promoted by the florist trade in Europe. The handsome new variety ‘Griffithii’ has recently been made available as seed.

Sowing: Sow directly where they are to flower from March to June
The seed is best sown direct, but can also be sown a little earlier in a cold frame. Prick out into individual pots when they are large enough to handle and plant them out in early summer. Sowing to flowering 14 to 16 weeks. If sown directly in the open in April, it will be in bloom by July or August.

Sowing Direct Surface sow the seed 50cm (20in) apart in well-cultivated soil which has been raked to a fine tilth. Do not cover the seeds as they need light to germinate. Water well. Germination will usually take 7-14 days (occasionally erratic to 30 days). Thin out seedlings to 50cm (20in) apart. Keep the compost moist but not waterlogged.

Cultivation:
Divide in spring. Larger clumps can be planted direct into their permanent positions. It is best to pot up smaller clumps and grow them on in a cold frame until they are well rooted before planting them out in the summer. Do not over fertilise because this will lead to excessive leaf growth. Collect seed for next year or leave to self sow.

Plant Uses:
Fresh cut flower. Foliage / filler for flower arranging. Flower beds and Borders.

Cut Flowers:
Remove all foliage that will be below the water line. Cut under water with a sharp knife. Hydrate in a solution of warm water and floral preservative / floral food for two hours before storage or usage. This plant is ethylene sensitive so take care not to place it near fruit or where it will be affected by car exhaust. Lasts 7 to 10 days.

Medicinal Uses:
Bupleurum has been used in traditional Chinese Medicine for at least 2,000 years and is famously used in the traditional "chai hu" for treatment of coughs, fevers, and influenza. The roots are harvested in the autumn and can be used fresh or dried. A paste of the plant is applied to boils.
It is the primary herb in dozens of classical formulations and a key ingredient in the formula known as sho-saiko-to, making up 16% of the formula. It is also a Japanese kampo or traditional herbal medicine formula based on the traditional Chinese formula xiao-chai-hu-tang. In English, it has been called minor bupleurum formula.

Other Uses:
The old plant is used as a fuel.

Nomenclature:
The genus name Bupleurum is taken from from the Greek bous meaning "ox," and pleuron meaning "a rib"
The common name Thorowax is the Old English for "Through grow", referring to the perfoliate leaves that are characteristic of many species
The Chinese name for Bupleurum - Chai Hu means kindling of the barbarians. The origin of this name is unclear.