When to Plant Onions in Arroyo Grande, CA

The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to determine when it's a good idea to plant onions by checking out the USDA zone info for Arroyo Grande.


Planting Calendar for Onions

Frost tolerance for onions: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Since onions do well in cold you can plant them earlier in the year than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant onions
Possibly ok, but a risky time to plant onions
Probably not a good time to plant onions

The earliest that you can plant onions in Arroyo Grande is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably October. If you wait any later than that and your onions may not have a chance to grow to maturity. If you are starting your onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Arroyo Grande. It might get as low as 25°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Arroyo Grande and it can change quite a bit from year to year. Since half of the time in Arroyo Grande you get a frost after February 15 be ready to protect your onions in the event of a late frost.

USDA Zone Info for Arroyo Grande

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)February 15
Average Date of First Frost (fall)December 15
Lowest Expected Low25°F
Highest Expected Low30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Arroyo Grande

You may be interested in your other planting guides for Arroyo Grande.