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.

The best time to plant phlox in Prosser should be figured out by using the USDA zone info.

Planting Calendar for Phlox

Frost tolerance for phlox:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Phlox are moderately cold tolerant which tells us that you can plant them a little bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant phlox in Prosser 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 phlox and expect a good harvest is probably September. You probably don't want to wait any later than that or else your phlox may not have a chance to really do well. If you are starting your phlox indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Since the USDA zone info for Prosser may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Prosser you get a frost after April 15 so make sure that you are prepared to protect your phlox if you have a late frost.

USDA Zone Info for Prosser

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 Prosser

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