One of the first steps you take when you are determining 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 USDA zone info for Johnston can be looked at to estimate when you can plant creeping phlox.

Planting Calendar for Creeping Phlox

Frost tolerance for creeping phlox:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Creeping Phlox do well in quite a bit of cold which means that you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant creeping phlox in Johnston is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant creeping phlox and expect a good harvest is probably September. Any later than that and your creeping phlox may not have a chance to fully mature. You can get started a few weeks earlier by starting your creeping phlox indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Johnston. It might get as low as -20°F during the coldest months of winter.

Remember that USDA zone info for Johnston is an average and the actual date of last frost is different every year. Since half of the time in Johnston there is a last frost after April 15 be ready to cover your creeping phlox if you have a surprise late frost.

USDA Zone Info for Johnston

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

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

Plants to Grow in Johnston

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