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

You should be able to determine when it's a good idea to plant iresene by reviewing the USDA zone info for Waterloo.

Planting Calendar for Iresene

Frost tolerance for iresene:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Iresene do not do well in cold weather which means that you need to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant iresene in Waterloo 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 iresene and expect a good harvest is probably August. You probably don't want to wait any later than that or else your iresene may not have a chance to grow to maturity. If you are starting your iresene 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 Waterloo. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Waterloo is not always accurate the actual date of last frost will vary from year to year. Half of the time in Waterloo there is a last frost after April 15 so make sure that you are prepared to cover your iresene in the event of one of those late frosts.

USDA Zone Info for Waterloo

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 Waterloo

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