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.

By checking out the USDA zone info for Iowa City you will be able to figure out when it's a good idea to plant bougainvillea.

Planting Calendar for Bougainvillea

Frost tolerance for bougainvillea:	Not tolerant of frost.
When to plant:	After the last frost.

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

The earliest that you can plant bougainvillea in Iowa City 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 bougainvillea and expect a good harvest is probably August. Any later than that and your bougainvillea may not have a chance to grow to maturity. If you are starting your bougainvillea indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Iowa City the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Iowa City and it will vary from year to year. Half of the time in Iowa City you get surprised by a frost after April 15 so make sure that you are prepared to cover your bougainvillea if you have a surprise late frost.

USDA Zone Info for Iowa City

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 Iowa City

You may be interested in your other planting guides for Iowa City.