Maintaining a sandarium: Keeping pioneer habitats active in July

Key points at a glance

• Sandaria are valuable habitats for ground-nesting wild bees, which quickly lose their function due to succession – the natural recolonisation by plants.
• July is the right time to mechanically remove emerging woody plants and nutrient-loving perennials to maintain the barren state of the area.
• Preserving open soil patches is essential for species such as the mining bee (Colletes cunicularius) or the yellow-masked bee (Hylaeus communis).

Understanding the dynamics of pioneer habitats

In a nature-friendly garden, a sandarium is designed as an artificial steep bank or an open sandy area. These sites imitate nutrient-poor pioneer habitats. In an ecological context, every bare substrate strives to develop a layer of vegetation. Without targeted maintenance, these open areas will turn into dense grassland or scrub within a few years as seeds blow in. For specialised species that rely on undisturbed, sandy soil, this process means the loss of their nesting grounds.

The following overview illustrates the target species and their requirements for maintenance in July:

Practical tips for July

1. Selective removal: Check the sandarium for germinating tree saplings such as field maple (Acer campestre) or young silver birch (Betula pendula). These must be removed along with their roots, as their shade lowers the soil temperature.
2. Mowing adjacent areas: If the surroundings of the sandarium are becoming heavily overgrown, mow them. Ensure that the grass cuttings are completely removed so that no nutrients are introduced into the poor soil of the sandarium.
3. Mechanical loosening: If the sand layer has become compacted due to rainfall, a superficial loosening with a small hand claw can help. This should be done carefully, however, so as not to destroy existing wild bee nesting burrows.
4. No fertiliser: To suppress the competitive strength of nutrient-loving plant species like common couch (Elymus repens), synthetic fertiliser must never be used in the immediate vicinity of the sandarium.

Conclusion

Maintaining a sandarium in midsummer is an active contribution to species conservation. By slowing down succession, you preserve the habitat for thermophilic (heat-loving) insects. A targeted intervention of a few minutes per month ensures the ecological quality of these valuable niches in your garden.

Frequently asked questions

How often do I need to maintain the sandarium?

Check for unwanted growth monthly during the growing season. In July, a quick 15-minute session for selective maintenance is usually sufficient.

Can I loosen the sand surface during hot weather?

Yes, but only superficially. Take care that no wild bee nesting burrows are destroyed by deep digging.

Why is shade on the sandarium harmful?

Many insects need direct sunlight to warm up their flight muscles. Shade cools the soil and makes it uninhabitable for larvae.

Main article: Nature-friendly garden in July: How to manage succession and pond ecology