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.

A common way of getting a good idea when it's the best time to plant lobelia is to consult the USDA zone info for Cottage Grove.

Planting Calendar for Lobelia

Frost tolerance for lobelia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since lobelia are very cold tolerant you can plant them much earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

On average the last frost has passed is on May 15 in Cottage Grove. You can expect an average low temperature of -25°F in the coldest months of winter.

Keep in mind that USDA zone info for Cottage Grove is an average and the actual date of last frost changes from year to year. Since half of the time in Cottage Grove you get surprised by a frost after May 15 be ready to protect your lobelia in the event of a surprise late frost.

USDA Zone Info for Cottage Grove

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Cottage Grove

You may be interested in your other planting guides for Cottage Grove.