Before planting it is a good idea to find your USDA Zone info to estimate 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.

You will be able to determine when it's possible to plant pearl onions by reviewing the USDA zone info for Altoona.

Planting Calendar for Pearl onions

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

Pearl onions can survive in very little cold which tells us that you can plant them a bit earlier in the year than more sensitive plants.

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

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

Last Frost Date

In Altoona the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Altoona may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Altoona there is a last frost after April 15 so always be ready to cover your pearl onions in the event of one of those late frosts.

USDA Zone Info for Altoona

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Altoona

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