When recreational gardeners plant their balcony boxes, the importance of the filling is often underestimated. However, the right substrate alone is not enough for perennials and flowers to develop furious blooms. Read here how to optimally fill a flower box in 3 steps.
How do you fill a flower box correctly?
In order to optimally fill a flower box, you should first create a 3-5cm high drainage made of inorganic material. Then spread out a breathable fleece and finally fill in high-quality, peat-free substrate, enriching plant soil with perlite or quartz sand.
Step 1: Drainage - effective challenge to waterlogging
If rain and irrigation water cannot drain freely into the flower box, your valuable plants have little chance of survival. Root rot is inevitable in waterlogged conditions. You can effectively prevent this problem if you first fill a balcony box with a 3 to 5 cm high drainage made of inorganic material. Potsherds, expanded clay, pebbles or chippings are well suited.
Re-drill floor holes if necessary
In plastic flower boxes, the important bottom holes are usually pre-punched. Please use a screwdriver to punch out these openings before filling in the drainage. Only then can it be ensured that no waterlogging can form in the planted balcony box.
Step 2: Spread out the breathable fleece
So that the soil crumbs in the substrate do not clog the drainage, place a thin fleece over it in the second step. For this purpose, use a material that is permeable to water and air and not foil.
Step 3: Optimize and fill substrate
Please do not give your valuable plants cheap potting soil from discount stores. Such substrates usually contain a high proportion of peat, which is questionable from an ecological and horticultural perspective. So grab a high-quality, peat-rich plant soil in the store, which you can optimize and fill in as follows:
- Enrich the potting soil by a third with Perlite breathing flakes (€5.00 on Amazon) or quartz sand
- Distribute the substrate successively with your hands onto the drainage and fleece
- Fill the balcony box no more than halfway with soil
Set the remaining substrate aside. Now plant the potted perennials and flowers. Finally, fill the balcony box with soil up to 2 finger widths below the edge so that no water spills over when watering.
Tip
If you build a wooden balcony box yourself, please line it with foil first. Only then do you fill the container with the substrate recommended here. A cut-open garbage bag can serve as a foil. A thin pond liner is of course more durable. Cut the film in a cross shape above the bottom holes so that rain and irrigation water can drain away.
