One of the first steps you take when you are figuring out your gardening schedule is find your 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 making a decision about when to plant periwinkles is to examine the USDA zone info for Hewitt.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Periwinkles require warm weather which tells us that it is important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant periwinkles in Hewitt 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 periwinkles and expect a good harvest is probably August. You probably don't want to wait any later than that or else your periwinkles may not have a chance to really do well. If you are starting your periwinkles indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Hewitt. In the coldest months of winter you can expect an average low temperature of 15°F.

Keep in mind 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 Hewitt and it will vary from year to year. Half of the time in Hewitt last frost occurs after March 15 so make sure that you are prepared to cover your periwinkles in the event of one of those late frosts.

USDA Zone Info for Hewitt

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

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

Plants to Grow in Hewitt

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