Only with a balanced and sufficient diet do farmer's hydrangeas form abundant flowers and develop into healthy, strong plants. The emphasis is expressly on "balanced", because both too much and too little fertilization damages the shrubs in the long term.
Cattle manure is one of the best fertilizers for farm hydrangea
Organic fertilization
Organic fertilizers are made from plant or animal source materials. They work slowly and evenly, as they are only gradually decomposed by microorganisms living in the soil. The microorganisms work faster at higher temperatures and correspondingly slower at lower ones. In any case, it takes about three to four weeks for the plants to absorb the applied fertilizer. The group of organic fertilizers includes u. mature compost, horn shavings (32.93€) and cattle manure.(18.80€)
Fertilize farmer's hydrangeas with cattle manure
Well-seasoned cattle manure (but not horse manure!) is one of the best organic fertilizers for farm hydrangeas because it has the right composition of nutrients and doesn't contain too much nitrogen. Mixed compost is also ideal for hydrangea fertilization. However, organic fertilizers have a serious disadvantage: their nutrient composition varies greatly, since they e.g. depends on the diet of the animals or plants.
mineral fertilization
Mineral fertilizers, on the other hand, are water-soluble and immediately available to the plants. They are commercially available in various mixtures or as individual minerals. Phosphate, potash and nitrogen belong to this group. When applying, you should keep in mind that any excess cannot be absorbed by the plants, but instead ends up in the groundwater. Therefore, even with a high nutrient requirement, you should fertilize more often, but more sparingly. A special hydrangea fertilizer is very suitable for farm hydrangeas, but rhododendron or azalea fertilizer also contains the right nutrient composition. However, universal fertilizers (e.g. blue grain) are unsuitable due to the high phosphate content.
Fertilize hydrangeas with blue flowers
The flower color of the farmer's hydrangea is naturally white, pink or red. Blue flowers are only achieved through the targeted treatment of the soil. Responsible for the blue coloring is the dye delphinidin, which, in the presence of the aluminum compound alum, colors the blossoms blue. If intensively blue-flowering varieties are to stay that way, you have to make sure that the soil is acidic and contains alum. The necessary alum is introduced into the soil with the irrigation water. To do this, you can either buy a ready-made preparation in a garden store, the so-called hydrangea blue, or you can go to the pharmacy and get potash alum (potassium aluminum sulphate), which is usually cheaper.
tips and tricks
A particularly valuable compost component for farmer's hydrangeas is old coffee grounds. It is even worth creating your own compost area where you accumulate a higher proportion of filter bags and shredded material. This natural fertilizer is not only suitable for hydrangeas, but also for evergreen plants and conifers.