One of the best tools that you have as gardeners to help us figure out 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.

A way of making a decision about when it's a good idea to plant phlox is to refer to the USDA zone info for Mount Vernon.

Planting Calendar for Phlox

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

Since phlox are one of those plants that can tolerate a little bit of cold weather you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant phlox in Mount Vernon 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. Any later than that and your phlox may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your phlox indoors.

Last Frost Date

The average date of last frost is April 15 in Mount Vernon. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Mount Vernon may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Mount Vernon last frost occurs after April 15 so be sure to be ready to protect your phlox in the event of a surprise late frost.

USDA Zone Info for Mount Vernon

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 Mount Vernon

You may be interested in your other planting guides for Mount Vernon.