The creamy-white flowers that coffee trees bloom in early spring are not only elegant in form and rich in fragrance, but also hold many fascinating botanical characteristics. This article guides you through the structure of coffee flowers, their flowering habits, and the differences in flowering periods among various varieties, and explains why drought or low temperatures can cause star-shaped flowers to appear, as well as how irrigation can increase the proportion of normal flowers. Whether you are a coffee enthusiast or a cultivation observer, you will gain practical knowledge about appreciating and cultivating coffee flowers.
Coffee flowers:
Every early spring, pure white coffee flowers cover the branches, looking especially fresh and lovely against the backdrop of downward-drooping green leaves. These flowers have a rich fragrance and a distinctive charm, though unfortunately their bloom does not last long.
Coffee flowers often cluster in the leaf axils in groups of several to dozens, with typically the 2nd to 5th flower borne on a single flowering axis. The flower color is white and fragrant. Varieties with small to medium-sized beans mostly have 5 petals, while large-bean varieties can have 7 to 8. The corolla is tubular and cylindrical in shape. The number of stamens often matches the number of petals, the stigma is divided into two forks, and the ovary is inferior, usually with 2 locules, occasionally with 1 or 3. Coffee flowers are entomophilous; large-bean and small-bean varieties are capable of self-pollination, while medium-bean varieties require cross-pollination.
Flowering habits:
Coffee flowers grow in the leaf axils. Flower buds can form in the leaf axils of both branches and the main trunk, but they are mainly concentrated on the branches. The formation of flower buds is closely related to the nutrient status within the branch and the external environment. Flower buds of medium-bean varieties begin to develop around late July, while those of small-bean varieties start between October and November. Branches of the current year can also form flower buds.
The flowering period of coffee varies depending on the variety and growing environment. Taking Hainan Island as an example, medium-bean varieties can bloom successively from November to June of the following year, with February to April being the peak blooming period. The peak blooming period for small-bean varieties is concentrated in March to May.
When flower buds reach the later stages of development, they require certain humidity and temperature conditions to open successfully. If drought or low temperatures occur, the flower buds may fail to open, or they may produce star-shaped flowers. The type intermediate between normal flowers and star-shaped flowers is called near-normal flowers. Star-shaped flowers have small, pointed, hard petals, no fragrance, and a yellowish or pale red color, with extremely low or even zero fruit set. Near-normal flowers can set fruit, but their fruit set rate is lower than that of normal flowers.
If drought occurs during the flowering period, irrigation can increase the proportion of normal flowers and reduce the appearance of star-shaped flowers.
The flowers of small- and medium-bean coffee typically begin to open between 3 and 5 in the morning, and reach full bloom between 5 and 7. Flower buds can only open when the temperature is below 10°C, while at temperatures above 13°C the buds cannot open normally.
Appreciation:
A few months later, they will turn into coffee cherries
The above content is compiled by CoffeeHunters, a coffee news website.
