When to Plant Bidens in Harlan, IA

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of getting a good idea when it's possible to plant bidens is to check out the USDA zone info for Harlan.


Planting Calendar for Bidens

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

It's a bad idea to plant bidens until after the last frost has passed because they are not cold tolerant.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant bidens
Possibly ok, but a risky time to plant bidens
Probably not a good time to plant bidens

The earliest that you can plant bidens in Harlan 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 bidens and expect a good harvest is probably August. If you wait any later than that and your bidens may not have a chance to really do well. If you are starting your bidens indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Harlan. You can expect an average low temperature of -20°F in the coldest months of winter.

Since the USDA zone info for Harlan is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Harlan there is a last frost after April 15 so always be ready to cover your bidens in the event of a surprise late frost.

USDA Zone Info for Harlan

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Harlan

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