When to Plant Tall Phlox in Gladstone, OR

The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when it's the best time to plant tall phlox is to consult the USDA zone info for Gladstone.


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 just a bit earlier in the year because they are moderately cold tolerant.

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 Gladstone 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 fully mature. You can get started a few weeks earlier by starting your tall phlox indoors.

Last Frost Date

The average date of last frost is March 15 in Gladstone. You should expect an average low temperature of 15°F in the coldest months of winter.

It's important to remember that USDA zone info for Gladstone is just an average and the actual date of last frost is different every year. Half of the time in Gladstone you get a frost after March 15 so always be ready to protect your tall phlox in the event of a surprise late frost.

USDA Zone Info for Gladstone

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°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 20°F.

Plants to Grow in Gladstone

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