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.

In Ottawa you can determine when it's the best time to plant sweet sultan by referring to the USDA zone info.

Planting Calendar for Sweet Sultan

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

You can plant sweet sultan just a tiny bit earlier in the year because they are barely cold tolerant.

The earliest that you can plant sweet sultan 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 sweet sultan and expect a good harvest is probably August. If you wait any later than that and your sweet sultan may not have a chance to fully mature. If you are starting your sweet sultan 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 should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Ottawa and it will vary from year to year. Since half of the time in Ottawa last frost occurs after April 15 be ready to cover your sweet sultan in the event of one of those late frosts.

USDA Zone Info for Ottawa

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Ottawa

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