One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

The earliest that you can plant periwinkles in Irving can be determined by looking at the USDA zone info.

Planting Calendar for Periwinkles

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

You really shouldn't plant periwinkles until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant periwinkles in Irving 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. If you wait any later than that and your periwinkles may not have a chance to grow to maturity. You can get started a little bit earlier by starting your periwinkles indoors.

Last Frost Date

The average date of last frost is March 15 in Irving. You should expect an average low temperature of 10°F in the coldest months of winter.

Remember 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 Irving and it can change quite a bit from year to year. Half of the time in Irving there is a last frost after March 15 so just be sure to be ready to protect your periwinkles if you have one of those late frosts.

USDA Zone Info for Irving

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Irving

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