Frost dates for Potter Valley Powerhouse, CA
When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.
Last spring frost
April 8
typical year
Safe to plant
April 29
frost is over in 9 of 10 years
First fall frost
November 6
typical year
Growing season
211 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Mar 11 – 25 | – |
| Spinach | – | Feb 25 – Mar 18 | Sep 11 – 25 |
| Lettuce | – | Mar 11 – Apr 1 | Sep 11 – 25 |
| Radishes | – | Mar 11 – Apr 22 | Sep 25 – Oct 9 |
| Onions | – | Mar 11 – 25 | – |
| Potatoes | – | Mar 18 – Apr 1 | – |
| Carrots | – | Mar 18 – Apr 8 | Aug 14 – 28 |
| Beets | – | Mar 11 – 25 | Aug 28 – Sep 11 |
| Kale | Jan 28 – Feb 11 | Mar 11 – 25 | Aug 28 – Sep 11 |
| Broccoli | Jan 28 – Feb 11 | Mar 25 – Apr 8 | Aug 28 – Sep 11 |
| Cabbage | Jan 14 – 28 | Mar 11 – 25 | Aug 28 – Sep 11 |
| Garlic | – | – | Sep 25 – Oct 16 |
| Warm-season crops | |||
| Tomatoes | Mar 4 – 18 | Apr 29 – May 13 | – |
| Peppers | Feb 25 – Mar 11 | May 6 – 20 | – |
| Cucumbers | – | Apr 29 – May 20 | – |
| Zucchini | – | Apr 29 – May 27 | – |
| Pumpkins | – | Apr 29 – May 20 | – |
| Green beans | – | Apr 29 – Aug 28 | – |
| Sweet corn | – | Apr 29 – May 27 | – |
| Basil | Mar 25 – Apr 8 | May 6 – 13 | – |
Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.
The year at a glance
Start indoors Plant outside Fall planting
The chance of frost, by date
| 1 year in 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | April 29 | April 8 | March 11 |
| Fall frost before | October 20 | November 6 | November 24 |
Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.
Hard freeze (28°F)
A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around February 28 (April 2 in a late year), and the first one in fall around November 22.
Where these dates come from
NOAA weather station POTTER VALLEY POWERHOUSE, CA US (USC00047109), 1991–2020 climate normals. It's the nearest station for 4 zip codes, all within 15 miles:
95469, 95470, 95485, 95493
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.