One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant thunbergia in Waterloo should be estimated by referring to the USDA zone info.

Planting Calendar for Thunbergia

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

You can not plant thunbergia until after all chance of frost has passed because they require warm weather.

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

Last Frost Date

In Waterloo the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Waterloo and it is different every year. Since half of the time in Waterloo you get a frost after April 15 be ready to protect your thunbergia in the event of a surprise late frost.

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.