The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of estimating when to plant four-o-clock flower is to consult the USDA zone info for Caldwell.

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.

You should not plant four-o-clock flower until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant four-o-clock flower in Caldwell 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. If you are starting your four-o-clock flower indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Caldwell. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Caldwell may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Caldwell there is a last frost after April 15 so make sure that you are ready to protect your four-o-clock flower if you have a late frost.

USDA Zone Info for Caldwell

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Caldwell

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