One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. 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 Manassas should be read to estimate when it's a good idea 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 all chance of frost has passed.

It's not a good idea to plant four-o-clock flower until after all chance of frost has passed because they require warm weather.

The earliest that you can plant four-o-clock flower in Manassas 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. You probably don't want to wait any later than that or else your four-o-clock flower may not have a chance to really do well. You can get started a couple of weeks earlier by starting your four-o-clock flower indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Manassas. In the coldest months of winter you can expect an average low temperature of 0°F.

Keep in mind that USDA zone info for Manassas may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Manassas you get a frost after April 15 so make sure that you are ready to protect your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Manassas

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 Manassas

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