What Fertilizer Is Best for Roses? A Detailed Guide to Key Fertilization Points

SummaryRoses should be fertilized with fertilizers containing nitrogen, phosphorus, potassium and trace elements. Such fertilizers can make the leaves of roses lush and the foliage green with red flowers, promote the formation of flower buds, make the rose root system more developed, and also promote new shoots and tender leaves of roses, increase the number of flowers and resistance, and enable healthy growth and development.

I. What Fertilizer Is Best for Roses

1. Nitrogen fertilizer

(1) Nitrogen fertilizer application is the most important nutrient for rose cultivation and affects growth and yield.

(2) An appropriate amount of nitrogen fertilizer can make the leaves of roses lush and the foliage green with red flowers.

(3) When nitrogen fertilizer is insufficient, roses become relatively weak, causing a slow growth cycle and yellowing leaves.

(4) When nitrogen fertilizer is excessive, roses tend to grow excessive branches, with few and loose flowers, and in severe cases even deformed flowers.

2. Phosphorus fertilizer

During the autumn flowering period, pay attention to supplementing phosphorus fertilizer as a base fertilizer. Phosphorus fertilizer can promote flower buds, lush leaves, bright flowers and a developed root system. When phosphorus fertilizer is insufficient, rose branches become weak and flowers droop.

3. Potassium fertilizer

Applying potassium fertilizer can not only promote new shoots and tender leaves, increase the number of flowers, make the flower buds plump and high in rose oil content, but also prevent diseases and pests.

4. Trace elements

In addition to nitrogen, phosphorus and potassium, an appropriate amount of trace elements such as iron, boron, manganese and zinc also needs to be added as a supplement. When trace elements are insufficient, diseases are likely to occur, causing leaf chlorosis and organ deformity, and the growth and development of roses will be affected.

II. Fertilization Requirements for Roses

1. Urea

Urea is generally applied in furrows or holes as a topdressing, with an application rate of 10-15kg/mu, 3-4 times/year, taking effect in 5-7 days. When applied to sandy soil, use small amounts multiple times, and water promptly after application.

2. Ammonium bicarbonate

(1) Ammonium bicarbonate, namely ammonium carbonate, is a quick-acting nitrogen fertilizer. Long-term application will not cause soil compaction, and it is widely used in production.

(2) It is generally applied in furrows or holes as a topdressing, with an application rate of 10-20kg/mu, 3-4 times/year, taking effect in about 2 days.

(3) However, because of its characteristics of rapid volatilization and easy dissolution, it is best to apply it in small amounts multiple times, cover the soil and water promptly after application, and avoid broadcasting on the ground to prevent leaves from being contaminated and burned.

3. Superphosphate

(1) Superphosphate is usually mixed with soil and miscellaneous fertilizers in autumn before application, which can speed up fertilizer efficiency. It is generally applied in furrows as a base fertilizer, with an application rate of 30-50kg/mu.

(2) When using, crush or pound it to avoid soil compaction and damage to the root system. In the late autumn growth period, spraying the leaves with a 1% superphosphate extract has a remarkable effect.

4. Calcium magnesium phosphate

Calcium magnesium phosphate fertilizer is basically similar to superphosphate in properties, usage and dosage, and its effect is even better. Calcium magnesium phosphate fertilizer is non-corrosive, does not absorb moisture or cake, and is convenient to use, so it is widely used.

5. Potassium sulfate

(1) Potassium sulfate has low mobility in soil, and can generally be applied in furrows as a base fertilizer or topdressing.

(2) However, long-term application easily causes compaction. Mixing it with organic fertilizer as a base fertilizer will have a better effect, with an application rate of 10-15kg/mu, 1 time/year.

(3) Before roses bud, foliar topdressing with 0.5% potassium sulfate is best, significantly increasing yield. It has a certain corrosiveness, so avoid leaf contamination and burning, and do not mix it with nitrogen fertilizer and superphosphate, as this reduces fertilizer efficiency.

6. Potassium chloride

Potassium chloride is basically similar to potassium sulfate in properties, usage and dosage, and should not be used in saline-alkali land.

7. Diammonium phosphate

Diammonium phosphate is a nitrogen-phosphorus compound fertilizer with lasting fertilizer efficiency. It is generally applied in furrows as a base fertilizer, with an application rate of 30-50kg/mu. When used as a base fertilizer, avoid mixing it with diammonium phosphate.

8. Potassium dihydrogen phosphate

Potassium dihydrogen phosphate is a phosphorus-potassium composite material with high solubility. The conventional concentration used is about 0.2%-0.3%. It is generally used as a foliar fertilizer, once every 2 weeks or in combination with pesticide spraying.