When to Plant Tall Phlox in Manchester, NH

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of getting a good idea when to plant tall phlox is to refer to the USDA zone info for Manchester.


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 moderately cold tolerant which means that you can get them planted earlier than other frost tender plants.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant tall phlox
Possibly ok, but a risky time to plant tall phlox
Probably not a good time to plant tall phlox

The earliest that you can plant tall phlox in Manchester 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. You can get started a couple of weeks earlier by starting your tall phlox indoors.

Last Frost Date

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

Since the USDA zone info for Manchester is not always accurate the actual date of last frost changes from year to year. Since half of the time in Manchester last frost occurs after April 15 be ready to cover your tall phlox in the event of one of those late frosts.

USDA Zone Info for Manchester

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 Manchester

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