Alpine Scree & Crevice Frequently Asked Questions
Direct answers to technical queries encountered by rock gardeners transitioning from lowland perennials to challenging high-altitude montane flora.
Why do alpine plants rot in standard potting soil?
High alpine plants have evolved in coarse mineral detritus with negligible organic humus. High-peat potting composts stay waterlogged, suffocating root hair cells and allowing fungal pathogens like Rhizoctonia and Botrytis to invade the plant crown within days.
What is the exact distinction between a rockery and a crevice garden?
A traditional Victorian rockery piles rounded stones horizontally with generous pockets of soil between them. A crevice garden sets stratified sedimentary slabs on edge with narrow 15-25mm vertical fissures packed with lean grit, actively cooling roots and preventing standing moisture.
What aggregate size is best for the collar mulch?
We recommend angular crushed grit between 3mm and 6mm. Never use fine building sand or pea gravel; rounded pea gravel shifts continually and traps moisture against delicate stems.
Can I grow high-altitude Saxifraga on an apartment balcony?
Yes. Hand-carved hypertufa troughs or weathered porous tufa stones placed on an open, breezy balcony provide the ideal drainage and airflow conditions needed by cushion saxifrages.
Should I fertilize alpine scree beds?
Never use high-nitrogen fertilizer. Excess nitrogen causes cushion plants to grow loose, floppy rosettes that immediately succumb to winter mold. An annual spring dusting of calcified seaweed or dilute potassium phosphate is sufficient.
How do I water an alpine crevice during severe heatwaves?
Never water overhead during the blazing afternoon heat. Water late in the evening around the perimeter base of the stone slabs. The water will soak into the deep subterranean strata without wetting the hot foliage.