When to Plant Catharanthus in Shenandoah, IA

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

One way of determining when you can plant catharanthus is to examine the USDA zone info for Shenandoah.


Planting Calendar for Catharanthus

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

You should not plant catharanthus until after the last frost has passed because they require warm weather.

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 Shenandoah 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. You probably don't want to wait any later than that or else your catharanthus may not have a chance to fully mature. Starting your catharanthus indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Shenandoah and it will vary from year to year. Since half of the time in Shenandoah you get surprised by a frost after April 15 be ready to cover your catharanthus if you have a late frost.

USDA Zone Info for Shenandoah

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 Shenandoah

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