One of the best tools that you have as gardeners to help us determine 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 Hamilton should be read to determine when you can plant four o' clock.

Planting Calendar for Four O' Clock

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

Four O' Clock require warm weather which tells us that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant four o' clock in Hamilton 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 grow to maturity. You can get started a couple of weeks earlier by starting your four o' clock indoors.

Last Frost Date

On average the last frost is on April 15 in Hamilton. It might get as low as -10°F during the coldest months of winter.

Remember that USDA zone info for Hamilton is an average and the actual date of last frost is different every year. Half of the time in Hamilton it frosts late in the year after April 15 so make sure that you are prepared to cover your four o' clock if you have a surprise late frost.

USDA Zone Info for Hamilton

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Hamilton

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