The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to determine when it's the best time to plant tall phlox by reviewing the USDA zone info for Crookston.

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 do well in moderate cold which tells us that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant tall phlox in Crookston is March. However, you really should wait until April 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 August. Any later than that and your tall phlox may not have a chance to really do well. Starting your tall phlox indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Crookston. In the coldest months of winter you should expect an average low temperature of -30°F.

Since the USDA zone info for Crookston is just an average the actual date of last frost is different every year. Half of the time in Crookston last frost occurs after May 15 so make sure that you are prepared to cover your tall phlox in the event of a surprise late frost.

USDA Zone Info for Crookston

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Crookston

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