One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when to plant onions is to check out the USDA zone info for Leavenworth.

Planting Calendar for Onions

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

You can plant onions much earlier in the year because they do well in cold.

The earliest that you can plant onions in Leavenworth 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. Any later than that and your onions may not have a chance to fully mature. You can get started a few weeks earlier by starting your onions indoors.

Last Frost Date

On average the last frost is on April 15 in Leavenworth. It might get as low as -10°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Leavenworth and it will vary from year to year. Half of the time in Leavenworth there is a last frost after April 15 so make sure that you are prepared to cover your onions in the event of a surprise late frost.

USDA Zone Info for Leavenworth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Leavenworth

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