Why do roses need to be fertilized in winter?
Here are some small experiences in green plant maintenance on why roses need to be fertilized in winter. Let's proceed with a comprehensive introduction.
Do roses, which have been regularly fertilized with water-soluble fertilizers, still need to be fertilized in winter? Today, let's talk about this issue, hoping it will be helpful to you.
Why do roses need to be fertilized in winter?
In areas with frost, roses enter a dormant period in winter, during which growth stops, making it a good time for us to apply winter fertilizer. Appropriate winter fertilization can supplement nutrients for roses, improve the soil environment, and because the temperature is low in winter, applying raw fertilizer that has not been fermented is less likely to cause fertilizer damage.
Applying sufficient winter fertilizer to roses in winter allows the fertilizer to decompose slowly in the soil, providing ample nutrients for the rapid growth of roses in the spring. Therefore, roses that have been given sufficient winter fertilizer often bloom more in the spring.
Especially for roses planted in the ground, which are often managed loosely with little fertilization throughout the year, winter fertilizer becomes particularly important as it is the basic nutrient for the entire year's growth.
The best time to apply winter fertilizer
The best time to apply winter fertilizer to roses is from the end of December to the beginning of February, which is the period from when roses enter dormancy to before new buds sprout. In cold northern areas, winter fertilizer should be applied before freezing.
Suitable fertilizers for winter fertilization
The fertilizers used for winter fertilization should be long-lasting, balanced, and rich in beneficial bacteria, making organic fertilizers a good choice. For example, sheep manure, chicken manure, rapeseed cakes, bone meal, fish scales, and fish intestines can be used. For roses planted in the ground, both raw fertilizers and well-fermented organic fertilizers can be used. For potted roses, it is recommended to use well-fermented organic fertilizers.
In addition to organic fertilizers, long-acting slow-release or controlled-release fertilizers can also be used, but it is recommended to use them in combination with organic fertilizers or microbial agents because slow-release and controlled-release fertilizers usually lack trace elements and have incomplete nutritional components.
Precautions for applying winter fertilizer
Roses bloom a lot in the spring, so when applying winter fertilizer, it is important to supplement phosphorus and potassium fertilizers and trace element fertilizers.
For example, when using rapeseed cakes as winter fertilizer, it is recommended to mix more bone meal and calcium magnesium phosphate fertilizers because rapeseed cakes have a higher nitrogen content, and mixing bone meal can supplement phosphorus and potassium fertilizers, resulting in better spring blooming. Sheep manure and chicken manure have relatively balanced nitrogen, phosphorus, and potassium contents, and adding bone meal is better, but it can also be used without it.
When using raw fertilizers that have not been fermented, it is recommended to dig holes and bury the fertilizer, making sure not to touch the roots of the roses. The fertilizer should be buried 10-20 cm away from the main roots. If raw fertilizer directly contacts the main roots, it can easily lead to black stems in roses. When burying raw fertilizers, insecticides and fermentation bacteria can be added to speed up the fermentation process of the raw fertilizers (if not available, insecticides can be added in the summer).
Whether it is well-fermented organic fertilizer or raw fertilizer, it should be solid when used, in the form of powder, chunks, or granules, but not semi-solid. If there is too much water, it can easily cause black stems in roses after application.
For roses planted in the ground, winter fertilizer can be buried or spread on the soil surface, while for potted roses, winter fertilizer should be applied when repotting. When repotting, add a sufficient amount of local fertilizer, with well-fermented organic fertilizer as the main component, supplemented by slow-release and microbial fertilizers.
In the dormant area of roses, applying winter fertilizer has clear timing and methods, while in southern regions, where there is no dormancy period, winter fertilization is often overlooked.
In southern regions, roses grow all year round and are often fertilized with water-soluble fertilizers, but to ensure sufficient fertilizer and water for roses, it is recommended to apply fermented organic fertilizer every 3 months or so. If this fertilization frequency can be maintained, there is no need to deliberately apply winter fertilizer.
The detailed explanation of why roses need to be fertilized in winter, the best time for winter fertilization, and the suitable fertilizers for winter fertilization provided above are for reference and suggestion only!