A Detailed Guide to Fertilizing and Managing Roses
How should roses be fertilized and managed? Please give guidance. Rose fertilization varies by season; 25% in summer and 12.5% in winter is suitable. Various nitrate-nitrogen and ammonium-nitrogen fertilizers can all be used, but urea is not suitable, especially on clay soil, because urea raises the soil pH. Rose fertilization...
How should roses be fertilized and managed? Please give guidance.
Rose fertilization varies by season; 25% in summer and 12.5% in winter is suitable. Various nitrate-nitrogen and ammonium-nitrogen fertilizers can all be used, but urea is not suitable, especially on clay soil, because urea raises the soil pH.
Rose fertilization is divided into root fertilization and foliar feeding. Apply sufficient base fertilizer when preparing the beds; in the early stage, apply little or no fertilizer. The required nitrogen:phosphorus:potassium ratio for roses is 1:1:2 or 1:1:3. Fertilization should follow the principle of applying thin fertilizer frequently. The concentration for foliar feeding should not exceed 0.3%. When fertilizing, pay attention to the following situations: fertilize after flowering to ensure the nutrients needed for the next bloom; after the beginning of autumn, apply more phosphorus and potassium fertilizer and less nitrogen fertilizer; fertilize before and after pruning; when foliar feeding, spray evenly and thoroughly, do not spray on rainy or cloudy days, and it is best to do it on a sunny, windless morning.
Common chemical fertilizer formulas include: 1 kg urea, 2 kg superphosphate, and 2 kg potassium sulfate mixed and applied promptly, 40 g per plant. Or 1.1 kg urea, 3.17 kg ordinary superphosphate, 3.17 kg potassium sulfate, and 0.45 kg magnesium sulfate mixed evenly and used immediately, not suitable for long storage, 28 g per plant.
Fertilization timing and method: Fertilization is usually carried out a few days after irrigation, when the soil is neither too dry nor too wet, by evenly scattering the fertilizer around the plant at a distance of 20-25 cm from the stem. If the plant density is high, band application can also be used, that is, scattering it between the rows of plants, then shallow cultivation and loosening of the soil, and watering to help the fertilizer dissolve and penetrate.
Supplementary chemical fertilizer is often applied after the previous crop has flowered, to encourage the plant to sprout new buds. Or it is applied in early spring when the soil temperature is low, microbial activity is poor, and organic fertilizer releases slowly, to encourage early flower bud emergence in spring. It is also applied after pruning or when the plant is deficient in nutrients.
Chemical fertilizer can also be dissolved in water to become a liquid fertilizer for application, but the application concentration must be carefully controlled. The ratio of total fertilizer to water is preferably 1 part per thousand or 2 parts per thousand; too high a concentration easily damages the root system and causes adverse consequences.
Foliar fertilization: Foliar fertilization is an auxiliary fertilization measure and cannot completely replace soil fertilization. Because foliar fertilization uses little fertilizer and takes effect quickly, with the fertilizer entering the sap flow within a few hours of application, it is especially suitable for targeted application when roses lack a certain element, so it has already been accepted by most growers.
Fertilizer combinations: They can be mixed and used according to the needs of roses, or used alone. The most commonly used combinations include: 1.25 g urea, 1.25 g monopotassium phosphate, and water, forming a complete nitrogen-phosphorus-potassium fertilizer at a concentration of 2.5 parts per thousand. Another formula is: 112.7 g urea, 112.7 g potassium sulfate, 56.3 g magnesium sulfate, 28.2 g ferrous sulfate, and 284.3 L water, at a concentration of 1.25 parts per thousand. A formula for correcting trace element deficiencies: 15 g manganese sulfate, 20 g magnesium sulfate, 10 g chelated iron, 5 g boric acid, and 25 L water, at a concentration of 2 parts per thousand.
Foliar fertilization timing and method: The solution concentration should be controlled at about 2 parts per thousand; too high a concentration easily damages the leaves. Do not apply when the leaves are too tender, because they do not yet have the ability to absorb nutrients. Both sides of the leaves should be thoroughly soaked. Do not spray before or after rain. Spray on a morning without strong wind. Do not spray on hot sunny days. Use a nozzle that sprays a fine mist. Urea can be mixed with certain pesticide and fungicide agents, and other fertilizers can also be mixed with pesticide and fungicide agents. To improve the effectiveness of foliar fertilization, a spreader can be added to the sprayed fertilizer solution; if there is none, neutral soap or laundry detergent can be added in an appropriate amount to the fertilizer solution and stirred until foam forms before spraying.
Spray when deficiency symptoms appear on the leaves, once every 7-10 days, and continue spraying until the deficiency symptoms disappear.
The general principles of the rose fertilization cycle: before cultivating roses, apply a large amount of organic fertilizer and an appropriate amount of phosphorus fertilizer; at the initial stage of planting roses, apply an appropriate amount of urea to promote early growth; after pruning and during the period of active rose growth, top-dress frequently.
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