Detailed Explanation of Potted Planting Methods and Care Techniques for Finger Citron
The leaves of finger citron are emerald green and remain evergreen throughout the four seasons. The fruit of finger citron is golden yellow, richly fragrant, and oddly shaped like a hand, in a thousand and one forms, making it delightful and endlessly fascinating. Finger citron not only has high ornamental value but also possesses precious medicinal and economic value. At the same time, finger citron can also be grown as a potted plant. Below we will look at the potted planting techniques for finger citron.
I. Potted Finger Citron Care Techniques
1. Seed Selection and Preparation
(1) Select excellent varieties that are cold-resistant, drought-tolerant, and suitable for potting. For domestic sales, emphasis can be placed on developing the "Nanjing variety"; for export, the "Xiaozhong" variety can be selected.
(2) Pot at the right time
2. Proper Shaping and Pruning
The golden finger citron tree mainly adopts the natural open-center form for shaping. Pruning of fruiting trees mainly consists of two types: spring pruning and summer pruning. Spring pruning is generally carried out before sprouting in spring. Summer pruning refers to pruning during the growing season, mainly removing dead branches, crossing branches, water sprouts, and diseased and pest-infested branches, and pinching and bud removal should be done in a timely manner. For old tree pruning, according to different cultivation conditions, measures such as heading back, thinning, and branch bending are adopted to achieve renewal.
3. Strengthen Fertilizer and Water Management
(1) Scientific fertilizer application
During the young stage or vegetative growth stage, N fertilizer is mainly applied; during the flower bud and fruiting stage, P and K fertilizers are mainly applied. Generally divided into base fertilizer, pre-flowering fertilizer, fruit-swelling fertilizer, etc. Regardless of the type of fertilizer, concentrated fertilizer, undecomposed fertilizer, and heavy fertilizer should be avoided, and the principle of "light fertilizer applied frequently" should be followed. Organic fertilizer should be the main type, with an appropriate amount of microelement fertilizer added.
(2) Reasonable watering
Watering should follow the rule of not watering when not dry, and watering thoroughly when watering, with alternating dry and wet periods. In the high-temperature seasons of summer and autumn, watering should be done in the early morning and evening; in winter and spring, it can be done after 9 a.m. In rainy seasons, the pot should be tilted so that no water accumulates in the pot.
4. Do Well in Flower and Fruit Thinning
For flower thinning, retain the large flowers and leafy flowers at the tips of the fruiting mother branches, and remove unisexual flowers and weak flowers. The degree of flower thinning depends on the tree's vigor and the number of flowers. Generally, for medium-flowering trees and heavy-flowering trees, it is appropriate to thin out 50%-60% of the total flowers. Fruit thinning should be carried out in several rounds, with about 40 leaves retained per fruit. For mature trees, fruit thinning should ensure more fruits are retained on the middle and upper parts of the canopy and fewer on the lower part.
5. Pay Attention to Pest and Disease Control
Diseases found include finger citron anthracnose, canker, and scab, which can generally be controlled with 50% carbendazim 800-fold solution or 70% thiophanate-methyl 800-1000-fold solution. Bordeaux mixture can also be used for control: before sprouting, use 0.8% lime equivalent formula; during the growing season, use 0.3%-0.5% lime double formula. Pests mainly include leafminers and red spiders, which can be controlled with omethoate, methamidophos, and propargite pesticides accordingly. In addition, there are pests such as swallowtail butterflies, scale insects, and scarab beetles, which can be sprayed with 40% isocarbophos 1000-fold solution or 80% dichlorvos 1000-fold solution and other pesticides.
6. Pay Attention to Safe Overwintering
Whether it can safely overwinter will directly affect the growth and development of young trees and the flowering and fruiting of mature trees. At present, Jinhua and other places generally use plastic greenhouses for overwintering, and it is best to move the finger citron pots into the greenhouse before mid-to-late November.
II. For potted finger citron, I have the following observations:
1. The growing medium should be fertile, especially with good bottom fertilizer, and it also needs to be permeable to water and air. The growing medium consists of two parts: the lower half uses sun-dried pigeon manure mixed with coarse granular peat soil as bottom fertilizer, filled to 1/2 of the pot. The upper half is a mixture of rice husk ash, garden soil, yellow sand, and a small amount of granular compound fertilizer. One strong finger citron seedling per pot is sufficient.
2. The flower pot should be a large pot with a diameter of about 25 cm to meet the requirements of moisture and fertilizer retention.
3. Light should be sufficient, and the pot should be turned at the right time; pinching is not needed. The plant will then be compact, sturdy, and full.
4. Usually water with vegetable-washing water or rice-washing water to keep the potting soil moist. From the beginning of flowering, spray a 3% potassium dihydrogen phosphate solution once every 7 days to promote flowering and fruiting, and it also helps clean dust from the leaf surface. However, everyone should be reminded that for usual fertilization or watering, it is still best to water the roots, especially during flowering, do not spray onto the flowers. In stormy weather, move the flower pot to a place sheltered from wind and rain, so that the plant is not torn or deformed.
The above are the potting techniques for finger citron. When planting finger citron, one should select excellent varieties that are cold-resistant, drought-tolerant, and suitable for potting, and at the same time shape and fertilize on schedule. Only in this way can good finger citron be grown.
Care Techniques for Potted Small-Fruited Golden Finger Citron
Pruning:Timely bud removal and pinching, mainly by manual pruning, supplemented by chemical bud control, and fully understanding the relationship between the growth and development of potted finger citron and its flowering and fruiting. By cutting off crossing, overlapping, overly dense, weak, and diseased and pest-infested branches, the requirements of even distribution of fruiting branches, short and thick branches, open inner canopy, and good ventilation are achieved. This displays the refinement and small size of potted golden finger citron.
The spring shoots that emerge each March, except those kept to fill gaps and support neighboring fruiting branches, can be cut off in time if they are not used as fruiting mother branches.
When summer temperatures are high, humidity is great, and nutrition is sufficient, the plant will produce a large number of branches with slender internodes, insufficient tissue, and no flower buds. Summer shoots emerge after the plant is moved out during "Guyu" (Grain Rain). Because they easily compete with spring fruits for nutrients and also affect the growth and development of autumn shoots, except for a few branches kept for shaping, the rest should all be thinned out. Cut off branches with more than 5 leaves and no flowers, horizontal branches, clustered buds at the cut, diseased and pest-infested branches, etc., so that nutrients meet the needs of flower and fruit growth. For some branches or trees that have not fruited for many years, a severe pruning should be carried out, leaving 3 to 4 buds at the base of the branch to promote the sprouting of new branches and fruiting.
Autumn shoots are rich in nutrients, grow thick and strong, have short internodes, and are full of tissue; the leaves on the shoots are small but thick, with strong leaves and dark green color, and are the basis for flowering and fruit setting the following year. Apart from cutting off thin and weak branches and overly dense branches, they are generally not pruned and basically should all be retained as fruiting mother branches for the next year. Therefore, autumn shoots should be given enhanced care, and this is the key to finger citron flowering more and bearing more fruit.
Fertilization:
The key technique for growing finger citron well is rational fertilization.
After young finger citron is potted in spring, if the potting soil uses nutrient soil with relatively high fertility, generally no further fertilization is needed that year. If substrate cultivation is used for finger citron, then after the seedlings are planted and watered, immediately place about 25 granules of imported compound fertilizer, and thereafter apply compound fertilizer once about every 15 days. The fertilizer can simply be evenly scattered on the surface of the substrate and will seep into the substrate with drip irrigation water or watering.
In mid-to-late August, apply decomposed organic fertilizer once more. It begins to fruit from the third year, and fertilization can then follow conventional management. Generally, it is moved outdoors around Guyu (Grain Rain), and sufficient base fertilizer is applied along with repotting, mainly decomposed cake fertilizer residue, plus a small amount of bone meal. After the seedlings recover, place them outdoors in a wind-sheltered, sunny place, and apply dilute cake fertilizer water once every 10 to 15 days until flower buds appear, then stop.
During the flower bud stage, spray the leaf surface once or twice with 0.2% potassium dihydrogen phosphate solution. After fruit set, apply dilute chicken or duck manure water or cake fertilizer water once about every 10 days, for two or three consecutive applications. To prevent chlorosis, it is advisable to water with 0.2% ferrous sulfate solution once every 15 to 20 days to keep the soil slightly acidic.
In the second year in spring, apply decomposed human manure, cake fertilizer water, etc. once every 15 to 20 days, for two or three consecutive applications.
Watering:
After the double-potting and transplanting are completed, watering is a must, and it must be thorough, so that the seedling roots and substrate are tightly bonded together. Because the substrate is light and has strong buoyancy, care should be taken when watering: use a watering can to spray, and do not pour heavily, otherwise the substrate may be washed out of the pot or holes may be washed into the substrate surface. At the same time, during the growth period, the potting soil should be kept moderately moist, preferably in a mostly moist state. In summer, watering should be sufficient, and the branches and leaves should be sprayed and washed frequently, and water should be sprinkled on the ground around the flower pot to lower temperature and increase humidity.
In the rainy season, it is better to keep it on the dry side to prevent excessive vegetative growth. In the early stage of fruit set, watering should be appropriately controlled to avoid fruit drop from too much water.
After the Beginning of Autumn, watering should be gradually reduced. In the north, move it indoors before Frost's Descent, place it in a sunny place, keep the room temperature above 5°C, control watering, and watering once every 7 to 10 days is sufficient. Spray and wash the branches and leaves once a week with clean water close to room temperature to prevent dust from accumulating on the leaf surface and causing leaf drop.
If conditions permit, a drip irrigation system can be installed; the cost is not too high and it can greatly reduce labor intensity. Watering time can be based on experience: when the soilless substrate feels 80% dry and the potted finger citron has become light in weight, it can be watered. Soilless cultivation substrate has strong water retention and air permeability, so too much water will not cause much harm.
In summer, there is a lot of rain, and small snails and wild slugs cause relatively serious damage. In mild cases, they bite holes in new and old leaves; in severe cases, they damage the finger citron fruit, greatly affecting its marketability. For this reason, deep ditches can be opened around the greenhouse to prevent water accumulation and increase the dryness of the ground inside the greenhouse, building the first line of defense. Second, spread slaked lime around to build a second line of defense, disinfecting and killing them on contact. Third, hand-pick them, crush them to death, or throw them into slaked lime; or use vegetable leaves to trap them: in the evening, scatter cabbage leaves or kale leaves on the seedbed to trap them, and check and kill them in the early morning.
In the early stage of damage, from March to April, apply 6% metaldehyde granules (250 grams per mu), or sprinkle tea seed cake liquid on the soil ridges around the seedbed for contact killing (1 kg tea seed cake powder mixed with 10 kg water, boiled for half an hour, rubbed and sieved, take the clear liquid, then mix with 60 kg water and stir well); 70-fold to 100-fold ammonia water can also be used and sprinkled near the plants at night; or control by spraying 800-fold to 1000-fold molluscicide solution. For snail control, 8% metaldehyde granule or 10% metaldehyde granule can also be used, at 1.5 grams per sq m.
Potted Finger Citron Techniques
Finger citron is a variety of citron and belongs to the citrus ornamental fruit plants. It is quite common for finger citron not to bloom, or to bloom without setting fruit, or to fail to hold fruit after setting. Below, I will introduce the techniques for potting finger citron!
Potted Finger Citron Techniques
1. Promote the vegetative growth of seedlings so they become mature plants as early as possible. In the second and third years, when repotting in spring, apply cake fertilizer, hoof pieces, and bone meal as base fertilizer, and at the same time carry out one shaping and pruning, cutting the main trunk to 15 cm and leaving 3-5 axillary buds below to promote the sprouting of strong branches and expand the canopy. When new shoots grow to 5-8 cm, pinch them, remove the terminal bud and side buds, to develop a certain tree shape and promote earlier entry into the fruiting stage.
2. Finger citron prefers acidic soil, and the pH value should be kept at 5.3; the potting soil ratio is 60% humus soil, 30% river sand, and 10% peat soil or furnace ash residue. A dilute fertilizer solution can be applied once every ten days to half a month. Too much water easily causes root rot, so the method of watering by testing moisture should be adopted: do not water when the surface layer of the potting soil is not dry, and water thoroughly each time, all year round.
3. The most suitable humidity for finger citron is 70%-90%. For this reason, in dry seasons, spray water on the leaves 1-2 times a day, and also sprinkle water on the ground to increase air humidity. The suitable growth temperature for finger citron is 15-30°C. In high-temperature seasons, it should be moved to a cool, ventilated, and shaded place. When the temperature is below 5°C, protection against cold is necessary.
4. Finger citron does not easily set fruit, so various methods must be used to promote fruit setting. During the flower bud stage, before flowering, and after flowering, organic fertilizer must be applied, and a dilute organic liquid fertilizer should also be applied once a week. Then carry out bud thinning: deformed buds and diseased or weak buds should all be removed. Do not retain too many buds; only retain the two or three best-growing buds near the top of the branch, and do not require too many fruits to set.
5. Finger citron is prone to yellow leaf disease and leaf drop. If yellow leaf disease occurs, irrigate with 1% ferrous sulfate solution. If root rot occurs, repot immediately, take the plant out of the pot, rinse the roots, remove the rotten roots, disinfect them, and plant them in sterilized plain sandy soil for care, so that they gradually recover.
How to Diagnose Problems in Finger Citron by Observing the Leaves?
If potted flowers are poorly managed, the leaves will turn yellow, scorch, and curl. Changes in the leaves can serve as a basis for analyzing problems in care work, and corresponding measures can be taken accordingly.
1. Young leaves turning yellow, or lower leaves curling and withering with continuous leaf drop, is generally caused by too much watering. Potted flowers should be watered according to “see dry, see wet”. If there is standing water in the flower pot, it should not exceed half an hour, otherwise root health will be affected. Sometimes, young leaves of potted flowers turn yellow because of a lack of some nutrient. If the leaves turn yellow but the veins remain green, it is caused by iron deficiency. At this time, some ferrous sulfate can be applied; using 3 parts fine sandy soil plus 1 part commercially available decomposed nitrogen-phosphorus fertilizer can also be effective.
2. Old leaves turning yellow and new leaves growing very small: this is due to a lack of nitrogen or phosphorus and potassium nutrition in the potting soil. Some decomposed organic fertilizer or commercially available flower fertilizer tablets can be applied to supplement nutrients. If the tips of young leaves scorch, check whether the potting soil is too dry, or whether the light is too strong and the temperature too high, scorching the plant.
3. New shoot tips shrinking, young leaves pale yellow, and old leaves dark yellow: this is mostly caused by water accumulation in the potting soil, lack of oxygen, and root rot. Immediately loosen the soil, stop fertilizing, and control watering. If the color of the new leaves at the growing tip is normal, but the lower leaves gradually dry, yellow, and fall upward or scorch, then it is due to lack of water.
4. Scorched leaf edges are often caused by too much fertilizer or improper watering. The potting soil can be rinsed multiple times with clean water, so that the fertilizer dissolved in the water flows out through the drainage holes.
5. Leaf edges curling, wrinkling, and turning brown: this is mostly caused by indoor air being too dry. Water close to room temperature should often be used to mist the leaf surface; or use the double-pot method, placing the flower pot inside another larger pot, with wet grass ash or wet old cloth strips stuffed between the two pots, so that there is a relatively humid microclimate around the potted flower.