Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when you can plant tall phlox in London 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.

You can plant tall phlox a little earlier in the year because they do well in moderate cold.

The earliest that you can plant tall phlox in London 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 grow to maturity. If you are starting your tall phlox indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in London. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for London is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in London it frosts late in the year after April 15 be ready to cover your tall phlox if you have a surprise late frost.

USDA Zone Info for London

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in London

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