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

You can determine when you can plant tall phlox in South Portland by referring to 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 do ok in mild cold which tells us that 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 South Portland 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. Any later than that and your tall phlox may not have a chance to really do well. You can get started a few weeks earlier by starting your tall phlox indoors.

Last Frost Date

On average the last frost has passed is on April 15 in South Portland. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for South Portland is an average and the actual date of last frost will vary from year to year. Since half of the time in South Portland it frosts late in the year after April 15 be ready to cover your tall phlox in the event of a surprise late frost.

USDA Zone Info for South Portland

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in South Portland

You may be interested in your other planting guides for South Portland.