Overview
- Experts say night frosts are still likely through mid-May in many parts of Germany and can kill warm‑season seedlings fast.
- The traditional Eisheiligen period from May 11 to 15 is the conservative marker many gardeners use for safer planting.
- Heat‑loving crops and balcony flowers face the highest risk, such as tomatoes, peppers, cucumbers, basil, petunias and geraniums.
- Because pots chill quicker than ground soil and can damage roots, keep citrus, oleander and hydrangeas protected, with citrus only outside once nights stay above about 5°C.
- If you plant early, use fleece or plastic covers at night, move small containers indoors during frost alerts, and harden off plants with short, wind‑sheltered daytime stints before full sun.