Basic rules for fertilization
It is important to know not only how to fertilize rhododendron at a certain stage of vegetation, but also how to do it correctly. Basic rules of care:
young plantings should be fertilized only with liquid compounds;
do not use chlorine-containing, lime fertilizers for rhododendron;
use useful fertilizers with phosphorus in the recommended dosage, since an excess of this mineral provokes chlorosis.
For lush flowering, choose preparations designed for your local climate and soil composition.
Wood ash is not used for a garden plot with rhododendron, since the substance changes the acidity of the soil and provokes chlorosis. Excess phosphorus has a negative effect on the absorption of iron by the plant.
Fertilizer application scheme
You can enhance the effect of using fertilizer for rhododendron by following these recommendations:
mineral granules and any other fertilizers should be applied not under the trunk, but at a distance of about 25 cm (10 inches), distributing them in the trunk circle along the projection of the crown;
when feeding the plant, move the mulch slightly and then put it back in place;
you can scatter fertilizers on the snow in winter so that in the spring, when the snow melts, the nutrient composition penetrates into the soil.
First fertilization
The first fertilization of rhododendron is carried out in early spring. Plants 30–60 cm (12-24 inches) high are fertilized with prolonged-release preparations at a rate of 60 g (2 oz) per 1 m2. Additionally, horn shavings are added (30 g (1 oz) per 1 square meter) for greater effect.
Second fertilization
Around June, when the flowers are blooming, use azofoska. It will strengthen the branches and support the plant at the stage of opening the buds.
Third fertilization
Top dressing of rhododendrons after flowering occurs in mid-summer. In July, the plant needs phosphorus and potassium. Despite the fact that the flowers have already bloomed, the plant needs care to lay buds for the next year. A mixture of 20 g (0.7 oz) of superphosphate and the same amount of potassium preparation will do.
Fourth fertilization
The last time the bush is cared for is when all the flowers have long since faded, and the plant needs to be prepared for winter. Choose preparations with potassium and phosphorus. The soil is watered abundantly, covered with pine needles.
Popular fertilizers
A separately growing bush is fertilized with mineral salts diluted with water. For mass planting, a mixture of 20 g of potassium sulfate, 20 g (0.7 oz) of superphosphate and 40 g (1.4 oz) of ammonium sulfate is suitable. This mixture is prepared for bushes with a height of 1 m (39.4 inches).
Effective fertilizers, according to experienced gardeners:
Pokon. Suitable for young plantings. The product is mixed with the soil by digging. After that, the soil is watered abundantly. For each adult bush, take 30 g (1 oz) of fertilizer. One feeding per season is enough.
ASB-Greenworld. Used for azaleas planted on acidic soils. The preparation stimulates development (growth), accelerates budding, makes the color of the leaves saturated. Apply once a quarter.
Agrecol. It is applied during planting at the rate of 10–50 g (0.3-1.8 oz) per 1 bush. The dosage varies depending on the size of the seedling. When fertilizing an adult bush, the preparation is scattered around the trunk, dug into the soil, and then watered. Repeat twice a season, once every 3 months.
