Hydrangeas are among the very robust flowering plants that do well in a wide variety of locations. In order for the hydrangea to produce many flowers and retain their original flower color, the substrate must be tailored to the special needs of this garden beauty.
Hydrangeas like acidic, nutrient-rich, humus-rich soil.
Demands on the soil conditions
The hydrangea prefers a nutrient-rich, deep, humus-rich and acidic soil. A low lime content is tolerated by most varieties. In order for the plants to thrive right from the start, it is important to prepare the substrate accordingly.
Hydrangea soil, a very special soil
The easiest way to create the optimal conditions is to plant in special hydrangea soil. This substrate has a pH of 4 to 4.5 and is enriched with all the trace elements that the hydrangea needs to grow. Alternatively, you can switch to rhododendron soil, which has roughly the same composition.
mix the soil yourself
If you want to create a whole border with the attractive flowering plants, you need a relatively large amount of the expensive substrate. Instead, mix hydrangea soil yourself. This also has the advantage that you can optimally match the substrate to the color of the flowers.
acidify soils
If the pH of the soil is well above 5, you should mix in acidifying agents for blue and pink flowering hydrangeas. Sand or peat quickly lower the pH value, although for ecological reasons you should only use peat in exceptional cases. Mix in rotted leaves, chopped wood, or grape pomace instead. Dampen the substrate and wait a week before measuring the pH again. If this is still too high, mix in a little more of the acidifying agents.
Blue hydrangeas, which thrive in this acidic soil, require an additional two-yearly hydrangea blue application.
Shift acidic soils to the alkaline range
Red and pink hydrangeas only retain their bright flower color in alkaline soil with a pH of at least 7. Below this value, the flowers gradually turn pink.
If the soil is loose, deep and able to store enough water, it is sufficient to lime the too acidic substrate at regular intervals. Since hydrangeas often show a lack of iron in alkaline soils, you should use a fertilizer that contains this trace element.
tips and tricks
In order to be able to estimate whether you need special soil, it is advisable to first carry out a soil analysis. Test sticks are available from specialist retailers. Alternatively, you can have a well-founded soil analysis, which also provides information about the trace elements present in the soil, carried out by a laboratory.