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.

The USDA zone info for Oswego should be reviewed to estimate when it's a good idea to plant tall phlox.

Planting Calendar for Tall Phlox

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

Since tall phlox are moderately cold tolerant you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant tall phlox in Oswego 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 grow to maturity. You can get started a few weeks earlier by starting your tall phlox indoors.

Last Frost Date

In Oswego 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.

Since the USDA zone info for Oswego is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Oswego you get a frost after April 15 so make sure that you are prepared to cover your tall phlox in the event of a late frost.

USDA Zone Info for Oswego

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 Oswego

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