Flower growers must learn the knowledge about top dressing. If you don’t learn it, you will regret it!

The two sides of topdressing

Top dressing, like repotting, also requires certain conditions. It depends not only on the season, but also on the performance of plant growth. Both must be taken into account and used when needed to promote growth, flowering and fruiting. On the contrary, blindly applying top dressing without considering the conditions can easily have a counterproductive effect, which can affect growth and cause fertilizer damage at the very least, or even kill the plant directly.

Topdressing conditions: temperature

Generally speaking, the temperature between 15 and 30 degrees is suitable for top dressing; but when the temperature continues to be below 15 degrees or continues to exceed 30 degrees, top dressing should be done with caution. If the temperature is too low or too high, the risk after top dressing will increase, which may easily lead to fertilizer damage.

Topdressing conditions depend on plant growth status

1. Under normal circumstances, the situations suitable for topdressing are the growth period (mainly nitrogen fertilizer); the bud period, fruiting period, and the post-flowering growth period of bulbous or perennial plants (mainly phosphorus and potassium fertilizers).

2. If the plant has just been transplanted and is in the stage of recovery, do not apply top dressing too early. At this time, top dressing will do more harm than good and affect its recovery.

In short, the simple description is "don't apply fertilizer if new leaves (buds) are not seen."

Methods of topdressing

1. General method: For most potted plants, when applying fertilizer, dig up the topsoil at the edge of the pot, put the fertilizer directly in, then cover it with soil and water it thoroughly. This method is suitable for both water-soluble and water-insoluble substances.

2. For water-soluble fertilizers, you can also mix it with part of the water and then spray it directly on the leaves of the plants (foliar fertilizer) or dissolve it directly in water and then water it directly.

Principles of topdressing

Apply thin fertilizer frequently

Thin fertilizer: When you don’t know the appropriate dosage, try to use less concentration (try to follow the instructions on the package, and reduce it as appropriate if the seedlings are too small).

Frequent application of fertilizer means applying fertilizer frequently. Applying small amounts frequently is most beneficial to plant growth. But there must be a limit to diligence. There should be at least a week between continuous topdressing. You cannot use this fertilizer today and that fertilizer tomorrow. Applying fertilizer too frequently will exceed the plant's tolerance limit over a long period of time and will also cause fertilizer damage. Also, do not give it too much fertilizer at one time and then not give it for a long time. This will cause the plant to overfeed and then starve for a long time, which is also not advisable.

special case

1. For plants in full bloom, they are very sensitive to water, fertilizer and environmental changes during this period. Generally speaking, for most plants that bloom and bear fruit regularly, basically no topdressing is needed during the full bloom period; however, for perennial herbaceous flowers, such as dwarf cattleya, geranium, carnation, sunflower, etc., topdressing can still be given to them during the full bloom period.

2. The above-mentioned method of top dressing is suitable for potted plants, especially observing the temperature conditions. Once the temperature is not suitable (too cold or too hot), it is best not to apply top dressing. However, for ground-planted plants, the temperature requirements are not so strict and can be relaxed appropriately. You can completely depend on the growth of the plants before determining whether top dressing is appropriate.

Replenish

Time for topdressing

It is best not to apply fertilizer at noon in summer and autumn. For foliar fertilizer application, it is best to do it in the afternoon when there is no direct sunlight or in the evening. Otherwise, the fertilizer sprayed on the leaves will evaporate too quickly, the leaves will not absorb it fully, and it is easy to cause sunburn on the leaves.