Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant lemon balm in Grinnell can be estimated by looking at the USDA zone info.

Planting Calendar for Lemon balm

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

You can plant lemon balm slightly earlier in the year because they are barely cold tolerant.

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Grinnell. It might get as low as -20°F during the coldest months of winter.

Since the USDA zone info for Grinnell is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Grinnell you get a frost after April 15 so make sure that you are prepared to protect your lemon balm if you have one of those late frosts.

USDA Zone Info for Grinnell

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Grinnell

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