Gardenia jasminoides Double Mint

Gardenia jasminoides Double Mint, recently obtained in the USA, is an outdoor hardy gardenia, suitable for zone 7, which stands out for its long flowering period and compact habit. This attractive shrub can be grown in the open ground in many regions, but exclusively in slightly acidic, fertile and moist soil. This variety is more resistant to certain root diseases and has glossy foliage that retains its beautiful dark green color even in winter. Its double white flowers with a sweet fragrance bloom from spring to summer. It is an exceptional plant that deserves a prominent place in a pot on the terrace or near the house.

Gardenia jasminoides is a shrub of the Rubiaceae family, native to Asia. It is frequently found in the wild in Vietnam, southern China, Taiwan, Japan, and India, in mild and humid, subtropical to tropical climates. Its cultivation in China dates back to at least a thousand years, and in recent years numerous American cultivars have been produced, some hardier than others.

'Double Mint', obtained in 2012 in the state of Georgia in the USA, is the result of crossing Gardenia 'Chuck Hayes' with an unknown variety, as part of a breeding program targeting perpetual flowering varieties. It stands out from other hardy cultivars due to its long flowering period, compact and bushy habit, resistance to root rot, and smaller leaves. It slowly forms an adorable shrub with a rounded, bushy habit, reaching about 70 cm (27.6 in) in all directions in pots under good conditions, slightly more in the open ground. Its 5 cm (2 in) diameter double white flowers, with a waxy texture, abundant from May to June, and sporadically until November, fade to a creamy yellow colour. Their fragrance is powerful, sweet, delightfully intoxicating, addictive. They appear solitary in the axils of the leaves, at the top of the branches, retaining their cream-white colour for two days before fading to a pale yellow. Each flower is composed of 6 to 8 true petals and 16 to 18 petal-like sepals. They contrast well with its shiny dark green leaves, about 4.2 cm (1.7 in) long and 1.7 cm (0.7 in) wide. The leaves are entire, thick, leathery, with very prominent veins. Its bark is grayish. Gardenias have a very long lifespan and are generally more floriferous in their youth.

Despite their somewhat demanding nature, Gardenias are among the most coveted shrubs by plant enthusiasts. It is undeniable that when the right conditions are met, the gardenia proves to be one of the most beautiful plants in the garden. However, the hardiness of certain varieties like Double Mint, which is proven in the open ground down to at least -12 °C (10.4 °F), represents an achievement in horticultural research. This hardiness should be moderated depending on the duration of freezing temperatures, exposure to dry and cold winds, and soil moisture content. It is possible to successfully cultivate Gardenia Double Mint in the open ground, in a sheltered location and in non-calcareous soil. It also grows very well in pots, where it can withstand mild winters without damage. It is often preferable, outside of privileged regions, to move it to a cold greenhouse during winter as a precaution. In the garden, camellias, rhododendrons, pieris, and kalmias will make excellent companions for this wonderful shrub.