One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Stillwater it's possible to figure out when you can plant four-o-clock flower.

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 when the weather gets warmer.

You should not plant four-o-clock flower until after the last frost because they are not cold tolerant.

The earliest that you can plant four-o-clock flower in Stillwater is May. However, you really should wait until June 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. You probably don't want to wait any later than that or else 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 few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Stillwater. It might get as low as -25°F during the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Stillwater and it can change quite a bit from year to year. Half of the time in Stillwater it frosts late in the year after May 15 so always be ready to protect your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Stillwater

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Stillwater

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