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.

In Grinnell you can estimate when to plant oleander by checking out the USDA zone info.

Planting Calendar for Oleander

Frost tolerance for oleander:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Oleander are not cold tolerant which means that it is important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant oleander in Grinnell 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 oleander and expect a good harvest is probably August. You probably don't want to wait any later than that or else your oleander may not have a chance to really do well. If you are starting your oleander indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Grinnell is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Grinnell it frosts late in the year after April 15 be ready to protect your oleander if you have a surprise late frost.

USDA Zone Info for Grinnell

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 Grinnell

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