Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Oshkosh can be looked at to estimate when it's the best time to 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 has passed.

It's probably a bad idea to plant four-o-clock flower until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant four-o-clock flower in Oshkosh 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. If you wait any later than that and your four-o-clock flower may not have a chance to grow to maturity. You can get started a little bit earlier by starting your four-o-clock flower indoors.

Last Frost Date

The average date of last frost is April 15 in Oshkosh. It might get as low as -20°F during the coldest months of winter.

Remember that USDA zone info for Oshkosh is not always accurate and the actual date of last frost is different every year. Half of the time in Oshkosh it frosts late in the year after April 15 so be sure to be ready to cover your four-o-clock flower in the event of a late frost.

USDA Zone Info for Oshkosh

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oshkosh

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