Planting Methods and Key Technical Points for California Poppy
California poppy (scientific name: Eschscholtzia californica Cham.), a perennial herb in the family Papaveraceae, is often grown as an annual or biennial. It has fairly strong cold resistance, prefers a cool and dry climate, and does not tolerate heat or humidity; in hot summers it enters a semi-dormant state, often withering and then sprouting again in autumn. It is native to California, USA.
The stems and leaves of California poppy are tender green with a grayish tint, and its flowers are bright and eye-catching. It is a good material for flower borders, flower paths and potted plants, and can also be planted in clusters on lawns.
Propagation Methods
Propagation by Sowing
Propagate by sowing. In areas where the soil does not freeze in winter, sow in autumn. In northern regions, raise seedlings indoors in early spring; at 15-20°C, seedlings emerge in about 7 days. Lift the seedlings and pot them up promptly before the true leaves unfold; after the frost-free period, remove them from the pots and plant them out with the soil ball (be careful not to damage the roots, otherwise they will not easily resume growth, or may even die); direct sowing in the open field before the ground freezes is also possible. Add windbreaks for protection, and the seedlings will emerge the following year. During the seedling stage, provide sufficient water and nutrients to promote robust growth.
Management After Sowing
After sowing in autumn, when a cold wave brings low temperatures, you can wrap the flower pots in plastic film to help keep them 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 and spindly; after most of the seeds have germinated, thin the seedlings appropriately: pull out the diseased and unhealthy seedlings so that the remaining seedlings have some space between them; when most of the seedlings have grown 3 or more leaves, they can be transplanted into pots.
Propagation by Cuttings
Cutting medium for California poppy: this refers to the nutrient soil, river sand, peat soil and other materials used for cuttings. For home cuttings, ideal cutting medium is hard to obtain due to limited conditions, so it is recommended to use the ready-mixed and sterilized cutting medium provided by this site; medium-coarse river sand can also be used, but it should be rinsed several times with clean water before use. Do not use sea sand or river sand from saline-alkaline areas; they are not suitable for the growth of flowering plants.
Selection of cutting stems: the stems used for cuttings are called cuttings. Usually, in combination with pinching, the thick, pest- and disease-free tips that are pinched off are used as cuttings, and the tips are used directly for rooting.
Management After Cutting
Temperature: the optimum temperature for rooting of cuttings is 18°C-25°C; below 18°C, rooting is difficult and slow; above 25°C, the cut end of the cutting is easily infected by pathogens and rots, and the higher the temperature, the greater the proportion of rot. When 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; when the temperature is too high after cutting, the main measure for cooling is to shade the cuttings, blocking out 50-80% of sunlight, and at the same time mist the cuttings 3-5 times a day; on sunny days with higher temperatures, mist more often, while on cloudy and rainy days with lower temperatures and higher humidity, mist less often or not at all.
Humidity: after cutting, the relative humidity of the air must be kept at 75-85%. Humidity can be increased by misting the cuttings, 1-3 times a day; the higher the temperature on sunny days, the more often you mist, while the lower the temperature on cloudy and rainy days, the less often you mist or you do not mist at all. However, excessive misting makes the cuttings prone to infection by pathogens and rot, because many kinds of pathogens exist in water.
Light: propagation by cuttings cannot do without sunlight, but 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 sunlight must be blocked, and after the root system has grown, gradually remove the shade net: on sunny days, remove the shade net at 4:00 every afternoon and put it back before 9:00 the next morning.
Key Points for Growing
When growing California poppy, pay attention to:
① California poppy has fleshy roots, prefers dryness, and is afraid of waterlogging. In the rainy season, pay attention to timely drainage for ground planting, and water potted plants in moderation; it is better to keep them dry than wet, to avoid the root crown turning black and rotting.
② Because California poppy is a taproot plant with a long main root, it does not tolerate transplanting, so it is best to sow the seeds directly in pots.
③ Plants sown in spring bloom in summer, but their growth and flowering are usually not as good as those sown in autumn. Therefore, sowing should preferably be done in August-September, with an optimum germination temperature of 15-20°C. If germination is uneven and seedlings come up too densely, proper thinning is needed. The planting spacing is 20-30 cm, and the planting site should be high and dry with good drainage. During the growing period, pay attention to loosening the soil and weeding, and cold-protection measures should be taken for overwintering in the open field.
④ After the fruit skin turns yellow, harvest promptly in the early morning, otherwise the capsules will split open on their own and cause the seeds to scatter.
② Because California poppy is a taproot plant with a long main root, it does not tolerate transplanting, so it is best to sow the seeds directly in pots.
③ Plants sown in spring bloom in summer, but their growth and flowering are usually not as good as those sown in autumn. Therefore, sowing should preferably be done in August-September, with an optimum germination temperature of 15-20°C. If germination is uneven and seedlings come up too densely, proper thinning is needed. The planting spacing is 20-30 cm, and the planting site should be high and dry with good drainage. During the growing period, pay attention to loosening the soil and weeding, and cold-protection measures should be taken for overwintering in the open field.
④ After the fruit skin turns yellow, harvest promptly in the early morning, otherwise the capsules will split open on their own and cause the seeds to scatter.
Daily Management
Autumn
After the sown seedlings have been potted up and have recovered for a period, fertilizer and water management should be stepped up quickly. Fertilizer and water management follows the cycle of "Huabao" - "Huabao" - clear water - "Huabao" - "Huabao" - clear water, with an interval of about 1-3 days; in winter and spring, the interval is shorter on sunny days or during high temperatures, and longer or no watering on cloudy and rainy days or during low temperatures.
Winter
Although it is still growing, the relatively low temperature slows its growth rate, and its demand for fertilizer and water is not great, so fertilizer and water may even need to be restricted. Fertilizer and water management follows the cycle of "Huabao" - clear water - clear water - "Huabao" - clear water - clear water, with an interval of about 4-7 days; watering should be arranged as much as possible at noon on sunny days when the temperature is relatively high.
Spring
After the temperature rises, growth resumes rapidly, and the plant gradually enters the flower bud differentiation stage and the flowering stage, with a great demand for fertilizer and water. Fertilizer and water management follows the cycle of "Huabao" - clear water - "Huabao" - clear water, with an interval of about 2-4 days; the interval is shorter on sunny days or during high temperatures, and longer or no watering on cloudy and rainy days or during low temperatures. After entering the seed-setting stage, stop fertilizer application.
Pruning
During the flowering process, cutting off the spent flowers together with three leaves can extend the flowering period.
Fertilizer and Water Management
Like other herbaceous flowers, it has a relatively high demand for fertilizer and water, but it is most afraid of careless fertilizing, concentrated fertilizer, and one-sided application of nitrogen, phosphorus, or potassium fertilizer. It is required to follow the two fertilizing (watering) principles of "apply dilute fertilizer frequently, use small amounts but more often, and provide complete nutrition" and "alternate dry and wet; when dry, dry thoroughly; do not water if not dry; when watering, water thoroughly", and after fertilizing, keep the leaves and flowers dry at night.
Pest and Disease Control
California poppy also dislikes continuous cropping. Under conditions of high temperature and high humidity, or with excessive fertilization, pests and diseases can occur. When diseased plants are found, in addition to timely chemical control, the diseased plants should also be pulled up and burned or deeply buried. At the same time, pay attention to field sanitation.