One of the first steps you take when you are getting a good idea 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 USDA zone info for Ottawa can be used to figure out when it's the best time to plant hypericum.

Planting Calendar for Hypericum

Frost tolerance for hypericum:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Hypericum are barely cold tolerant which means that you can plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant hypericum in Ottawa is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant hypericum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your hypericum may not have a chance to grow to maturity. If you are starting your hypericum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Ottawa. You can expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for Ottawa is just an average and the actual date of last frost will vary from year to year. Since half of the time in Ottawa last frost occurs after April 15 be ready to cover your hypericum if you have a surprise late frost.

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.