Last frost
/ˌlæst ˈfrɔst/
Definition
Last frost refers to the final spring date on which freezing temperatures, usually 32°F or lower, are expected in a given area. In gardening, it is a climate and timing concept used to mark when frost-sensitive plants are less likely to be damaged outdoors. Unlike the first frost, which ends the growing season in fall, last frost marks the usual transition into safer planting conditions.
Practical Relevance
- Planting schedules: Gardeners use last frost to time sowing and transplanting of tender crops such as tomatoes, peppers, and basil, which can be injured or killed by freezing temperatures.
- Risk to new growth: Even hardy plants can suffer damage if warm weather triggers fresh shoots or flower buds before last frost, because young tissues often tolerate cold less well than dormant parts.
- Local variation: The date is an average, not a promise. Elevation, nearby water, urban heat, and low-lying frost pockets can shift conditions within the same region.
- Season extension decisions: Knowing last frost helps when using row covers, cold frames, or cloches, and it guides when to harden off seedlings so outdoor exposure is safer.
Related Terms
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