How to Grow Croton? A Detailed Guide to the Latest Cultivation Methods
Croton is also known as golden-spotted fig, variegated laurel, etc. It is a shrub or small tree of the genus Codiaeum in the Euphorbiaceae family, native to Malaysia and the Pacific region, and now widely cultivated in tropical regions. It is commonly cultivated in the southern provinces and regions of our country. This species is a common foliage plant for courtyards or parks in tropical and subtropical regions, with many horticultural varieties. Now let us take a look at the cultivation methods for croton!
Croton Seed Propagation
1. Seed selection: Before sowing, the seeds must first be selected. Whether the seeds are selected well or not directly affects whether sowing can succeed. It is best to use seeds harvested in the current year. The longer the seeds are stored, the lower their germination rate. Choose seeds that are plump and free of defects or deformities, and also choose seeds free of pests and diseases.
2. Disinfection: Disinfection includes two concepts: one refers to disinfecting the seeds, and the other refers to disinfecting the sowing substrate. For household seed disinfection, it is common to soak the seeds in hot water at about 60°C for a quarter of an hour, then use warm water to promote germination for 12-24 hours. The best way to disinfect the sowing substrate is to put it in a pot and heat it while stirring; any pests and diseases will be killed by the heat.
3. Germination promotion: Soak the seeds in warm water (at a temperature similar to face-washing water) for 12-24 hours until the seeds absorb water and swell. For very common seeds that germinate easily, this step can be skipped.
4. Sowing: For tiny seeds that are difficult to pick up by hand or with other tools, you can moisten one end of a toothpick with water and stick the seeds one by one onto the surface of the substrate, then cover with substrate 1 cm thick. After that, place the sowing pot into water, with the water depth at 1/2-2/3 of the pot's height, and let the water slowly soak upward.
5. Management: After sowing in late autumn, early spring, or winter, if a cold wave with low temperatures occurs, you can wrap the flower pot in plastic film to help keep it warm and moist. After the seedlings emerge, uncover the film promptly, and let the seedlings receive sunlight before 9:30 every morning or after 3:30 in the afternoon; otherwise, the seedlings will grow very weak. After most of the seeds have sprouted, appropriate thinning is needed.
Croton Cutting Propagation
1. Substrate: For home cuttings, it is difficult to obtain an ideal cutting substrate due to limited conditions. It is recommended to use the already prepared and sterilized cutting substrate provided by this site. Medium-coarse river sand can also be used, but it must be rinsed several times with clean water before use. Do not use sea sand or river sand from saline-alkali areas; they are not suitable for the growth of flowering plants.
2. Cuttings: When doing softwood cuttings, during the vigorous growth period from late spring to early autumn, select sturdy current-year branches as cuttings. After cutting the branches off, choose the robust parts and cut them into sections 5-15 cm long, each section bearing more than 3 leaf nodes. When cutting the cuttings, note that the upper cut should be made flat about 1 cm above the topmost leaf node, and the lower cut should be made at an angle about 0.5 cm below the bottommost leaf node. Both the upper and lower cuts should be smooth (the knife must be sharp).
3. Temperature: The optimal temperature for rooting of cuttings is 20-30°C. Below 20°C, rooting of cuttings is difficult and slow; above 30°C, the upper and lower cuts of the cuttings are easily infected by pathogens and rot, and the higher the temperature, the greater the proportion of rot. If low temperatures occur after cutting, the main measure for keeping warm is to wrap the flower pot or container used for cuttings in plastic film.
4. Humidity: After cutting, the relative humidity of the air must be maintained at 75-85%. The basic requirement for rooting of cuttings is that before the cuttings root, they must be kept fresh and tender so they can carry out photosynthesis to produce rooting substances. However, cuttings that have not rooted cannot absorb enough water to maintain their internal water balance, so spraying must be used to reduce water evaporation from the cuttings.
5. Light: Cutting propagation cannot do without sunlight, because the cuttings still need to continue photosynthesis to produce nutrients and rooting substances to supply their rooting needs. However, the stronger the light, the higher the temperature inside the cuttings, the more vigorous the transpiration of the cuttings, and the more water they consume, which is not conducive to the survival of the cuttings. Therefore, after cutting, 50-80% of the sunlight must be shaded, and after the root system grows out, gradually remove the shading net.
Croton Cultivation Methods
1. Soil: Croton likes fertile, moist, well-drained soil. For potting, use 3 parts garden soil, 1 part compost, and 1 part river sand, or mix 3 parts coarse peat, 3 parts leaf mold, and 2 parts sand as the substrate.
2. Sunlight: Croton has a relatively wide range of adaptability to light, but sufficient sunlight helps promote its good growth and obtain higher ornamental value. Therefore, apart from needing appropriate shading under strong summer light, in spring, summer, and autumn, the leaf color becomes more beautiful under outdoor light conditions. Croton is not very shade-tolerant and is generally suitable for placement indoors in a spot with strong diffused light, and the time should not exceed 2-3 weeks. If there is a long-term lack of light or insufficient light, the leaves will lack luster and are also prone to falling off.
3. Watering: During the growth period from May to October, croton should be given relatively sufficient water, spraying water on the leaves and ground every day to maintain relatively high air humidity and clean leaf surfaces. In late autumn and winter, gradually reduce the amount of watering, but be sure to spray water on the leaves, keep the indoor air humid, and provide appropriate ventilation.
4. Temperature: Croton likes heat and fears cold. The safe indoor wintering temperature in winter is 10-15°C. Below 10°C, leaf drop easily occurs, and water-soaked spots or discoloration may also appear on the branches. In summer, it can adapt to high temperatures above 30°C.
5. Fertilization: Croton is generally given 1 application of decomposed liquid fertilizer every 2 weeks. Nitrogen fertilizer must not be too much, otherwise the leaves will turn green and dull, and lose their vivid color. From late autumn to winter, fertilize less or not at all, so as to avoid producing new shoots.
6. Pests and diseases: If the cultivation environment is hot and dry, croton is prone to damage by scale insects, red spider mites, and aphids. For red spider mites and aphids, spray 1000 times diluted dimethoate solution for control. For scale insects, spray 100-150 times diluted petroleum emulsion for control. If sooty mold occurs, wipe with clean water or spray 500-1000 times diluted carbendazim solution.