One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. 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 Ottawa you should be able to figure out when it's the best time to plant tropical hibiscus.

Planting Calendar for Tropical Hibiscus

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

Since tropical hibiscus are not cold tolerant you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant tropical hibiscus in Ottawa 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 tropical hibiscus and expect a good harvest is probably August. If you wait any later than that and your tropical hibiscus may not have a chance to grow to maturity. Starting your tropical hibiscus indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Ottawa the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Remember that USDA zone info for Ottawa is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Ottawa you get a frost after April 15 be ready to cover your tropical hibiscus in the event of one of those late frosts.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ottawa

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