When Do Finger Citrons Ripen? A Detailed Guide to Their Ripening Time

Finger citrons generally ripen in September-October each year. When the fruit ripens, the core separates from the peel, forming slender, curved segments that look like fingers. So, what are the cultivation techniques for finger citron?

1. Planting

Finger citron is not cold-tolerant and is relatively shade-tolerant. Overly strong light can cause sunscald or damage its shallow root system. Its optimum growing temperature is 10-31°C; below 0°C it must be moved into a greenhouse to overwinter, and it can still grow normally at 43°C. In Guangdong and Guangxi it can be planted in the open field, at about 110 plants per mu. Finger citron is not strict about soil quality; loose, fertile, well-aerated, well-draining sandy loam is best, followed by yellow-red sandy soil. Seedlings can be planted in all four seasons once the new shoots turn green, with the best planting periods being January-May and August-September.

2. Fertilizing

Fertilization of finger citron should be determined by the age of the tree and how well it is growing. Generally, in the first 3 years, a quick-acting organic fertilizer should be applied once a month from March to August; after entering the full fruiting stage, fertilizer can be applied 3 times a year, respectively before flowering, during the young fruit stage, and after harvesting, promptly applying bran cakes, compost, human and livestock manure and urine along with phosphorus and potassium fertilizer or compound fertilizer. Particular attention should be paid to applying winter fertilizer well.

3. Field Planting

After cutting-propagated or grafted seedlings have been grown for one year, when the young plants reach 50 cm in height, they can be planted in either spring or autumn, with February, when temperatures begin to warm and new buds are about to sprout, being better. Generally, on previously cultivated land, first dig drainage ditches around the perimeter, then dig holes at a spacing of about 3 m between plants and rows; if planting along field edges and corners, they can be slightly closer. The holes should be about 50 cm in diameter and 30 cm deep, with the soil inside the holes broken up fine, and it is best to arrange them in a triangular pattern. Plant one seedling per hole, making sure it is upright, with the fibrous roots spreading in all directions; bank fine soil around the roots, lift gently upward several times so the roots and soil are in close contact, then cover with fine soil and firm it down, finally covering with soil slightly higher than ground level.

4. Management

During the flowering period of finger citron, excess flowers and male flowers can be removed, leaving only 1-2 flowers per short branch. Alternatively, waiting until young fruits have formed and then thinning them is even safer. In winter, clear away fallen leaves and residual branches. During the growing season, remove severely diseased leaves as they appear and bury them deeply or burn them to prevent reinfection by pathogens. In field-planted finger citron orchards, dig deep ditches around the perimeter to lower the groundwater table, maintain suitable soil moisture, and enhance soil permeability. Spray nitrogen, phosphorus, and potassium fertilizers as well as trace-element fertilizers and Greenfenwei on the leaves; spray borax at the early flowering and full flowering stages to increase leaf lifespan and photosynthetic capacity, promote branch maturity and nutrient accumulation, enhance plant resistance, and increase yield.

5. Pruning

Cut the main trunk back to 15 cm, leaving 3-5 axillary buds below to encourage vigorous shoots to sprout and expand the canopy. When new shoots grow to 5-8 cm, pinch off the growing tips, removing the terminal buds and lateral buds, to develop a certain tree shape and promote earlier entry into the fruiting stage.

6. Weeding

Flowering begins around Jingzhe (March 6). For each flower cluster, select and keep 2-3 healthy female flowers and remove the rest. In terms of fruit-setting techniques, it is generally best to keep 1-2 fruits per branch, and any extra ones should be removed. Once the plant enters the fruiting stage, pull out weeds around the plant by hand; do not use a hoe, to avoid damaging the roots. After planting finger citron, soil should be banked up once a year for 5 years, carried out after pruning and clearing the orchard, and after banking up, cover the tree basin with a thin layer of grass.

7. Harvesting

Harvesting the fruit: the fruits begin to ripen successively from the end of August. When the peel starts to change from green to light yellow-green, harvest on a sunny day, continuing until harvesting is finished in winter. Cut the fruit lengthwise with a knife into thin slices 4-7 mm thick, and sun-dry or oven-dry them promptly. For mature, strong trees under good management, each tree yields 20-25 kg of fresh fruit per year.

Ripe finger citrons are golden yellow in color and constantly give off fragrance, eliminating odors, purifying indoor air, and inhibiting bacteria. Friends who are interested can try growing them.