One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant four-o-clock flower in Cambridge should be figured out by referring to the USDA zone info.

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.

Four-o-clock flower require warm weather which means that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

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

Last Frost Date

The average date of last frost is April 15 in Cambridge. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Cambridge is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Cambridge last frost occurs after April 15 be ready to cover your four-o-clock flower in the event of a surprise late frost.

USDA Zone Info for Cambridge

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 Cambridge

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