One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Hillsdale should be reffered to in order to figure out when it's the best time to plant tall phlox.

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 moderately cold tolerant which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant tall phlox in Hillsdale 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 grow to maturity. If you are starting your tall phlox indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Hillsdale. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Hillsdale may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Hillsdale there is a last frost after April 15 so make sure that you are prepared to cover your tall phlox in the event of one of those late frosts.

USDA Zone Info for Hillsdale

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°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 -10°F.

Plants to Grow in Hillsdale

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