The best time to plant tulip bulbs is in the fall, when the soil starts to cool down but before it freezes. Generally, this means:
- In colder climates (US zones 3 to 5), plant in September.
- In transitional climates (zones 6 to 7), plant in October.
- In warmer climates (zones 8 to 9), plant in November or December.
The key is to plant the bulbs about 6-8 weeks before the first hard frost or before the ground freezes, allowing the bulbs to establish roots in cool soil. For cooler northern areas, that can be around September-October, while in milder or warmer regions it may be later, up to December. If the soil temperature does not drop enough to provide natural chilling, pre-cooled bulbs should be planted immediately after chilling (e.g., from a fridge) in early winter. Plant bulbs pointed-end up, about 5-7 inches (12-15 cm) deep, spaced 8-15 cm apart depending on display preference, in well-drained, enriched soil. This timing and method help ensure strong root growth and beautiful spring blooms. So, the general recommendation is to plant tulip bulbs in autumn—September through November depending on climate—with some flexibility into December or possibly January in milder regions, but not later than February to avoid poor blooms.