Regular fertilizing of your hydrangea ensures magnificent blooms and healthy growth. There are a few things to consider when administering blue grain.
Hydrangeas love acidic soil and mainly need nitrogen for healthy growth, but only a little phosphorus. If you fertilize it regularly, your plant will be strengthened and form powerful flowers.
Blaukorn – A fertilizer for all cases?
Blaukorn is an artificially produced commercial fertilizer that should be used with caution. If it seeps into the groundwater via nutrients, which also serves as drinking water, or if it is ingested directly, it can lead to nausea, diarrhea, vomiting or even cancer. The wildlife in your garden also suffers if you use blue grain regularly.
Blue grain not very suitable for hydrangeas
However, the dosed addition of blue grain as fertilizer for your vegetable and garden plants enables you to achieve high yields during the harvest. However, blue grain is not well suited for hydrangeas.
- Blue grain contains as much nitrogen as phosphorus. However, the hydrangea needs more nitrogen than phosphorus.
- Blaukorn dissolves in irrigation water and rainwater and is therefore dependent on the weather.
- If you intend to turn your hydrangea blue by adding aluminum, blue grain will prevent this. Instead, blue grain brings the original color back up.
- Overdosing is very harmful to the plant.
- During cold periods, blue corn is not degraded, which leads to freezing of buds in winter.
alternative fertilizers
With natural fertilizers you can also achieve the desired effect without harming yourself, the plant or the environment. These alternatives are worthwhile:
- Hornmehl
- Hornspäne
- coffee grounds
- leaf compost
- bark mulch
Blue hydrangeas need a special hydrangea fertilizer with aluminum compounds to keep their intense colour.
How often to fertilize your hydrangeas
The following applies to the right time of application:
- Fertilize your hydrangeas in spring, before the growing season, and in early summer, by July at the latest.
- Give hydrangeas in tubs regular liquid fertilizer from March to the beginning of August.
- Once your hydrangea is in full bloom, stop fertilizing.
- No fertilizing is required before wintering.
Tip: The pH of the soil affects the color of the flowers. If the pH is around four, blue flowers form. If it is over five, it favors pink flowers. You can get a pH tester at a hardware store.
