One of the best tools that you have as gardeners to help us determine 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.

The best time to plant celosia in Harvard can be estimated by reviewing the USDA zone info.

Planting Calendar for Celosia

Frost tolerance for celosia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since celosia require warm weather it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant celosia 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 celosia and expect a good harvest is probably August. If you wait any later than that and your celosia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your celosia indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Harvard. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that USDA zone info for Harvard is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Harvard last frost occurs after April 15 so just be sure to be ready to protect your celosia in the event of a surprise 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.