---
title: Hardiness Zones Guide
created: 2026-05-24
updated: 2026-05-24
type: concept
tags: [zones, hardiness, frost, growing-season]
sources: [entities/*.md]
---
# Hardiness Zones Guide
## Overview
USDA Plant Hardiness Zone reference for SeedVault crops. Determines your frost dates and growing season length.
## Zone Reference
### Last Frost Dates (Approximate)
| Zone | Avg Last Spring Frost | Avg First Fall Frost | Growing Days |
|------|----------------------|---------------------|-------------|
| 3 | May 15 | Sept 15 | ~120 |
| 4 | May 1 | Sept 15 | ~135 |
| 5 | April 15 | Oct 1 | ~170 |
| 6 | April 1 | Oct 15 | ~195 |
| 7 | March 15 | Nov 1 | ~230 |
| 8 | March 1 | Nov 15 | ~260 |
| 9 | Feb 15 | Dec 1 | ~290 |
| 10 | Dec 15 | Feb 1 | 365+ |
## Crop Viability by Zone
### Zone 3-4 (Short Season, ~120-135 days)
**Will grow:** Focus on fast-maturing cool-season crops
- [[snowball-turnips]] (35-50 days) ✓
- [[butter-crunch-butterhead-lettuce]] (45-60 days) ✓
- [[provider-green-bush-beans]] (50-55 days) ✓
- [[red-russian-kale]] (50-60 days) ✓
- [[bulls-blood-beets]] (50-60 days) ✓
- [[scarlett-nantes-carrot]] (65-75 days) ✓
- [[pickling-cucumber]] (50-60 days) — start indoors
- [[sugar-lace-snap-peas]] (50-60 days) ✓
**Challenging:** Warm-season crops need greenhouse or very early indoor start
- [[roma-tomatoes]] — possible with indoor start (70-80 days + 6-8 weeks indoors)
- [[california-wonder-sweet-pepper]] — very tight (60-80 days + 8-10 weeks indoors)
**Likely won't mature:** Long-season crops
- [[utah-celery]] (100-130 days) ✗
- [[crimson-sweet-watermelon]] (85-90 days) ✗
- [[jack-o-lantern-pumpkin]] (90-110 days) ✗
- [[sugar-beets]] (90-120 days) ✗
### Zone 5-6 (Medium Season, ~170-195 days)
**Full catalog viable** except the longest-season crops:
- All warm-season crops mature with indoor start
- [[jack-o-lantern-pumpkin]] and [[crimson-sweet-watermelon]] are tight but possible
- [[utah-celery]] needs early indoor start
### Zone 7-8 (Long Season, ~230-260 days)
**Everything grows well.** Two fall planting cycles possible for cool-season crops.
- Fall planting of kale, turnips, lettuce, beets, carrots
- Extended warm season allows late summer planting of beans, cucumbers
### Zone 9-10 (Year-Round, ~290-365 days)
**Continuous planting year-round.**
- Cool-season crops planted in fall/winter
- Warm-season crops planted in spring/summer
- Multiple succession plantings of everything
- [[red-russian-kale]] thrives in cool winter months
- [[coriander-cilantro]] won't bolt as quickly in cooler months
## Tree Seeds — Zone Requirements
| Tree | Zones | Notes |
|------|-------|-------|
| [[red-cedar]] | 3-9 | Native to Eastern NA, very hardy |
| [[chinese-elm]] | 5-9 | Semi-deciduous in warmer zones |
| [[southern-yew]] | 7-10 | Needs milder winters |
| [[japanese-maple]] | 5-9 | Protect from harsh winter winds |
## Growing Season Calculator
For any zone: **Your Growing Days ≈ (First Fall Frost - Last Spring Frost)**
To check if a crop will mature:
- **Direct sow:** Growing Days > Crop Days-to-Harvest
- **Indoor start:** Growing Days + Indoor Weeks > Crop Days-to-Harvest
- **Fall planting:** 60-75 days before first frost for fast crops, 90-120 for slower
## Microclimate Tips
- South-facing walls add 1-2 zones
- Raised beds warm 5-10°F faster
- Cold frames extend season by 2-4 weeks each side
- Mulch protects roots from freeze
- Black plastic warms soil for early transplanting
## Related
- [[planting-schedules]]
- [[seed-catalog]]
- [[grow-guides]]