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

You should be able to determine when it's possible to plant tall phlox by reviewing the USDA zone info for Carlsbad.

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 well in moderate cold which tells us that you can start planting them earlier than other plants that might not handle the cold.

The earliest that you can plant tall phlox in Carlsbad 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. You probably don't want to wait any later than that or else 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 March 15 in Carlsbad. It might get as low as 10°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Carlsbad and it can change quite a bit from year to year. Half of the time in Carlsbad last frost occurs after March 15 so always be ready to protect your tall phlox in the event of a late frost.

USDA Zone Info for Carlsbad

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Carlsbad

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