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.

It's possible to determine when to plant tall phlox by referring to the USDA zone info for Silverton.

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 ok in a little bit of cold which means that you can plant them a little bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant tall phlox in Silverton 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 really do well. Starting your tall phlox indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Silverton. It might get as low as 10°F during the coldest months of winter.

It's important to remember that USDA zone info for Silverton is just an average and the actual date of last frost will vary from year to year. Half of the time in Silverton you get surprised by 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 Silverton

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 Silverton

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