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 way of estimating when to plant tall phlox is to examine the USDA zone info for Humboldt.

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 one of those plants that can tolerate a little bit of cold weather which tells us that you can start planting them earlier than other frost tender plants.

The earliest that you can plant tall phlox in Humboldt 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 fully mature. If you are starting your tall phlox indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Humboldt the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Remember that USDA zone info for Humboldt may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Humboldt it frosts late in the year after April 15 be ready to protect your tall phlox if you have a surprise late frost.

USDA Zone Info for Humboldt

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Humboldt

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