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.

A way of determining when it's a good idea to plant tree onions is to look at the USDA zone info for Buffalo.

Planting Calendar for Tree onions

Frost tolerance for tree onions:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since tree onions are barely cold tolerant you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant tree onions in Buffalo is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant tree onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tree onions may not have a chance to grow to maturity. Starting your tree onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Buffalo. In the coldest months of winter you can expect an average low temperature of -25°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Buffalo and it is different every year. Half of the time in Buffalo you get surprised by a frost after May 15 so always be ready to protect your tree onions in the event of a late frost.

USDA Zone Info for Buffalo

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Buffalo

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