Zone 5 Winter Dormancy: Unheated Stairwell With North Windows Works

Stairwell Strategy: Solid Plan

Unheated stairwell with north-facing windows (bright indirect light) in Zone 5 (Michigan) = excellent dormancy spot.

Key Details

• Temps in 30s°F = perfect.
• Keep damp, not soggy.
• Remove dead leaves.
• Spray sulfur fungicide preventatively.
• Light: minimal photosynthesis occurs, but window proximity helps.

Drosera binata Exception

Keep D. binata (typical) in your apartment window — it goes dormant by photoperiod, then resumes growth in February. No cold needed.

Follow-Up: binata Complex Variability

• Dichotoma 'Giant': Hardy to Zone 8 in large pots. Survives outdoors in W. Oregon.
• T-forms (NZ): Very hardy.
• Multifida: Light frost OK.
• 'Marston Dragon': Light frost OK.
• Multifida 'extrema': Tropical — no hard freeze, no true dormancy with light.