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.

It's a good idea to determine when to plant cosmos by looking at the USDA zone info for Preston.

Planting Calendar for Cosmos

Frost tolerance for cosmos:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since cosmos are one of those plants that can tolerate a tiny bit of cold weather you can plant them just a tiny bit earlier in the year than more sensitive plants.

The earliest that you can plant cosmos in Preston is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant cosmos and expect a good harvest is probably August. Any later than that and your cosmos may not have a chance to fully mature. If you are starting your cosmos indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Preston the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Preston and it will vary from year to year. Since half of the time in Preston you get surprised by a frost after April 15 be ready to cover your cosmos in the event of a late frost.

USDA Zone Info for Preston

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 Preston

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