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When to Plant Four-o-clock flower in Harvard, IL

One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

You can figure out when it's a good idea to plant four-o-clock flower in Harvard by reviewing 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 all chance of frost has passed.

Four-o-clock flower require warm weather which means that it is important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant four-o-clock flower
Possibly ok, but a risky time to plant four-o-clock flower
Probably not a good time to plant four-o-clock flower

The earliest that you can plant four-o-clock flower in Harvard 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. Any later than that and 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 little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Harvard. In the coldest months of winter you can expect an average low temperature of -15°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Harvard and it can change quite a bit from year to year. Half of the time in Harvard it frosts late in the year after April 15 so just be sure to be ready to cover your four-o-clock flower in the event of a late frost.

USDA Zone Info for Harvard

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Harvard

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