One of the best tools that you have as gardeners to help us figure out 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 Marathon you can estimate when it's a good idea to plant penstemon by referring to the USDA zone info.

Planting Calendar for Penstemon

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

Penstemon do well in moderate cold which tells us that you can plant them a little bit earlier than other plants that might not handle the cold.

The earliest that you can plant penstemon in Marathon is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant penstemon and expect a good harvest is probably November. You probably don't want to wait any later than that or else your penstemon may not have a chance to really do well. You can get started a few weeks earlier by starting your penstemon indoors.

Last Frost Date

In Marathon it never frosts. You can expect an average low temperature of 45°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 Marathon and it changes from year to year. Since it never frosts in Marathon you do not have to be ready to protect your penstemon in the event of one of those late frosts.

USDA Zone Info for Marathon

Here is the info for USDA Zone 11b.

Average Date of Last Frost (spring)	Never
Average Date of First Frost (fall)	Never
Lowest Expected Low	45°F
Highest Expected Low	50°F

This means that on a really cold year, the coldest it will get is 45°F. On most years you should be prepared to experience lows near 50°F.

Plants to Grow in Marathon

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