When to Plant Catharanthus in Osceola, IA

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Osceola should be reviewed to figure out when to plant catharanthus.


Planting Calendar for Catharanthus

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

Since catharanthus require warm weather it's necessary to wait until after the last frost has passed before you can plant them.

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

The earliest that you can plant catharanthus in Osceola 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 catharanthus and expect a good harvest is probably August. Any later than that and your catharanthus may not have a chance to grow to maturity. Starting your catharanthus indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Osceola is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Osceola it frosts late in the year after April 15 be ready to cover your catharanthus in the event of a surprise late frost.

USDA Zone Info for Osceola

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 Osceola

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