The episodes of drought are becoming more frequent in Belgium as elsewhere. A resilient garden is not just a garden that "survives"; it is a garden that remains beautiful despite the heat and lack of water, while also being sustainable and easy to maintain.
Here is a clear guide, based on good horticultural practices and recommendations from the Royal Horticultural Society (RHS), the Mediterranean Conservatory, and studies on soil management in variable climates.
1. Understanding the principles of a DRY garden
A dry garden rests on three pillars:
- A suitable and draining soil, which prevents water stress in summer and asphyxiation in winter.
- Resilient plants, capable of managing heat, UV and drought.
- A strategic management of mulching and minerals, which limits evaporation and stabilises soil temperature.
These elements allow the garden to maintain its structure, colour, and health even during extreme episodes.
2. Prepare a resilient soil: drainage + structure
a) Create a very well-draining soil
It is the foundation of the dry garden.
Heavy (clay) soils retain water and "suffocate" the roots in winter, which causes the mortality of Mediterranean plants. Horticultural studies show that water resilience is highly dependent on drainage.
How to do it?
- Incorporate fine gravel, coarse sand (no river sand) or pumice 2/6.
- Work the soil to a depth of 25 to 40 cm.
- Avoid the classic compost that retains too much moisture.
b) Create light mounds (recommended technique for sensitive plants)
Many drought-resistant plants die not in summer... but in winter, due to excess water.
The proven solution: drainage mounds.
Advantages :
- Natural vertical drainage.
- Faster warming of the soil in spring.
- Reduction of root diseases.
Method:
Create a mound of 15 to 30 cm, made up of a mixture:
- 50% garden soil
- 30% gravel / coarse sand
- 20% mature compost
3. Choose truly drought-resistant plants
Horticultural research identifies several families particularly well-suited:
a) Mediterranean plants (resistance + aesthetics)
- Lavandula angustifolia
- Perovskia atriplicifolia
- Cistus
- Santolina
- Achillea
- Salvia nemorosa and Salvia officinalis
- Rosmarinus officinalis (romarin)
b) Highly resilient grasses (structure + movement)
The grasses stabilise the soil, withstand dry winds and require little water.
- Stipa tenuissima
- Stipa gigantea
- Pennisetum alopecuroides
- Miscanthus sinensis
- Sesleria nitida
c) Xerophytic perennials (summer maintenance + long duration)
- Echinops
- Gaura lindheimeri
- Verbena bonariensis
- Nepeta faassenii
- Eryngium planum
- Agastache
d) Resistant shrubs
- Eleagnus ebbingei
- Arbutus unedo
- Pittosporum tenuifolium
- Nerium oleander (to be protected in winter in the north of Belgium)
4. Mulch management: a scientifically validated technique
Why mulch?
The studies of the RHS Water Management Program show that a well-chosen mulch:
- reduces soil evaporation by up to 40%,
- stabilise the temperature,
- limits weeds,
- protects the soil microorganisms.
What mulch for a dry garden?
-
Mineral: gravel, crushed slate, pumice
→ Perfect for Mediterranean and xerophytic plants -
Vegetal: wood chips, branch chippings
→ Ideal around shrubs; decomposes slowly and enriches the soil
Thermal insulation tip:
Layer the materials: 3 cm of compost + 5 cm of mineral mulch.
5. Integrate the mineral to reduce maintenance
A dry garden is not only botanical: it is also a mineral design.
The mineral zones:
- reduce the area to be watered,
- limit the growth of weeds,
- create an interesting light/dark contrast.
Ideas to integrate:
- dolomite paths
- large slabs of natural stone
- decorative stonework
- contemporary rockeries
- gravel garden areas (type dry English garden)
6. Care for delicate plants in Belgian climate
Many drought-resistant plants do not tolerate:
- very wet winters,
- waterlogged soils,
- late frosts.
Sensitive plants to protect or raise:
- Agaves
- Yuccas
- Some sages (microphylla, greggii)
- Young olive trees
- Cistus in heavy soil
- Echiums (very sensitive to cold + humidity)
Practical solutions:
- Planting on draining mounds
- Use mineral mulch to prevent stagnant moisture
- Install a winter cover on very sensitive plants
- Avoid the low areas of the garden (risk of frost + water stagnation)
7. Water intelligently
Even in a dry garden, some plantings require installation watering.
The rules:
- Water deeply but infrequently.
- Always water at the base, never on the foliage.
- Encourage watering early in the morning.
- Install the drip system if necessary, but keep a minimalist line.
8. Example of a “resilient” planting plan
Low structure:
- Nepeta
- Verbena bonariensis
- Achillea
- Stipa tenuissima
Average structure:
- Lavandes
- Sauges
- Pennisetum
High structure:
- Miscanthus
- Arbutus
- Eleagnus
Vertical touches:
- Eryngium
- Echinops
- Agapanthes
Conclusion: a beautiful, sustainable garden fit for the future
Creating a resilient garden does not mean sacrificing aesthetics.
On the contrary, dry gardens are among the most elegant: grey tones, silver foliage, light grasses, chic minerals… It is a sustainable, contemporary style that is suited to climate change.