One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can determine when to plant scallions in Altoona by using the USDA zone info.

Planting Calendar for Scallions

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

You can plant scallions slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant scallions in Altoona 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 scallions and expect a good harvest is probably August. Any later than that and your scallions may not have a chance to grow to maturity. Starting your scallions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Altoona. You should expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Altoona and it is different every year. Since half of the time in Altoona you get surprised by a frost after May 15 be ready to protect your scallions in the event of a surprise late frost.

USDA Zone Info for Altoona

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 Altoona

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