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.

You should be able to estimate when it's the best time to plant portulaca by using the USDA zone info for Louisville.

Planting Calendar for Portulaca

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

Portulaca do not do well in cold weather which means that it's important to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant portulaca in Louisville 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 portulaca and expect a good harvest is probably August. Any later than that and your portulaca may not have a chance to grow to maturity. If you are starting your portulaca indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Louisville. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Louisville may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Louisville it frosts late in the year after April 15 be ready to cover your portulaca if you have a surprise late frost.

USDA Zone Info for Louisville

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Louisville

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