One of the first steps you take when you are getting a good idea 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 best time to plant periwinkles in Helotes can be estimated by checking out 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.

Periwinkles do not do well in cold weather which means that it is necessary 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 Helotes 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. 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

On average all chance of frost has passed is on March 15 in Helotes. You can expect an average low temperature of 15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Helotes is an average and the actual date of last frost will vary from year to year. Since half of the time in Helotes you get a frost after March 15 be ready to protect your periwinkles if you have a surprise late frost.

USDA Zone Info for Helotes

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 Helotes

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