Before planting it is a good idea to find your USDA Zone info to estimate 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.

You should be able to figure out when to plant four-o-clock flower by reviewing the USDA zone info for Hampshire.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant four-o-clock flower until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant four-o-clock flower in Hampshire is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant four-o-clock flower and expect a good harvest is probably August. Any later than that and your four-o-clock flower may not have a chance to grow to maturity. Starting your four-o-clock flower indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Hampshire. In the coldest months of winter you should expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Hampshire is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Hampshire there is a last frost after April 15 be ready to cover your four-o-clock flower if you have a late frost.

USDA Zone Info for Hampshire

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 Hampshire

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