One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant phlox in Sullivan should be determined by checking out the USDA zone info.

Planting Calendar for Phlox

Frost tolerance for phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant phlox a little earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant phlox in Sullivan 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 phlox and expect a good harvest is probably September. If you wait any later than that and your phlox may not have a chance to grow to maturity. If you are starting your phlox indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Sullivan the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Sullivan may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Sullivan you get surprised by a frost after April 15 so always be ready to cover your phlox in the event of a surprise late frost.

USDA Zone Info for Sullivan

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Sullivan

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