One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant pearl onions in Johnston can be figured out by looking at the USDA zone info.

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.

Since pearl onions are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant pearl onions in Johnston 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 really do well. You can get started a few weeks earlier by starting your pearl onions indoors.

Last Frost Date

The average date of last frost is April 15 in Johnston. You should expect an average low temperature of -20°F in the coldest months of winter.

Always keep in mind that USDA zone info for Johnston is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Johnston last frost occurs after April 15 be ready to cover your pearl onions in the event of one of those late frosts.

USDA Zone Info for Johnston

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 Johnston

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