One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant rhubarb in Havre can be figured out by referring to the USDA zone info.

Planting Calendar for Rhubarb

Frost tolerance for rhubarb:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant rhubarb a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant rhubarb in Havre 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 rhubarb and expect a good harvest is probably August. If you wait any later than that and your rhubarb may not have a chance to fully mature. Starting your rhubarb indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Havre. You can expect an average low temperature of -30°F in the coldest months of winter.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Havre and it changes from year to year. Half of the time in Havre there is a last frost after May 15 so be sure to be ready to cover your rhubarb if you have a surprise late frost.

USDA Zone Info for Havre

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Havre

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