Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to determine when it's the best time to plant onions by reviewing the USDA zone info for Toppenish.

Planting Calendar for Onions

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

Onions do well in cold which tells us that you can start planting them much earlier than more sensitive plants.

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

The last month that you can plant onions and expect a good harvest is probably September. 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 couple of weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Toppenish. It might get as low as 0°F during the coldest months of winter.

Keep in mind that USDA zone info for Toppenish is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Toppenish you get surprised by a frost after April 15 so make sure that you are prepared to cover your onions in the event of a late frost.

USDA Zone Info for Toppenish

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Toppenish

You may be interested in your other planting guides for Toppenish.