One of the first steps you take when you are figuring out 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.

In Sullivan you can estimate when it's the best time to plant tall phlox by checking out the USDA zone info.

Planting Calendar for Tall Phlox

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

Tall Phlox are one of those plants that can tolerate a little bit of cold weather which means that you can plant them a little bit earlier than more sensitive plants.

The earliest that you can plant tall 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 tall phlox and expect a good harvest is probably September. If you wait any later than that and your tall phlox may not have a chance to really do well. If you are starting your tall phlox indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Remember that USDA zone info for Sullivan is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Sullivan you get surprised by a frost after April 15 be ready to cover your tall 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.