One of the first steps you take when you are getting a good idea 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.

In Henderson you can determine when it's a good idea to plant periwinkles by referring to 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 the last frost because they are not cold tolerant.

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

Last Frost Date

The average date of last frost is April 15 in Henderson. In the coldest months of winter you should expect an average low temperature of -5°F.

Since the USDA zone info for Henderson is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Henderson it frosts late in the year after April 15 so make sure that you are ready to cover your periwinkles in the event of one of those late frosts.

USDA Zone Info for Henderson

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Henderson

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