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.

A way of estimating when to plant four o' clock is to consult the USDA zone info for Holland.

Planting Calendar for Four O' Clock

Frost tolerance for four o' clock:	Not tolerant of frost.
When to plant:	After the last frost.

Since four o' clock are not cold tolerant you really should wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant four o' clock in Holland 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 and expect a good harvest is probably August. If you wait any later than that and your four o' clock may not have a chance to fully mature. Starting your four o' clock 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 Holland. In the coldest months of winter you can expect an average low temperature of -5°F.

Remember that USDA zone info for Holland is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Holland there is a last frost after April 15 be ready to protect your four o' clock in the event of one of those late frosts.

USDA Zone Info for Holland

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 Holland

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