One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of making a decision about when you can plant nasturtium is to use the USDA zone info for Madison.

Planting Calendar for Nasturtium

Frost tolerance for nasturtium:	Not tolerant of frost.
When to plant:	After the last frost.

Nasturtium do not do well in cold weather which tells us that it's necessary to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant nasturtium in Madison is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant nasturtium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your nasturtium may not have a chance to grow to maturity. If you are starting your nasturtium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Madison the average date of last frost happens on April 15. It might get as low as -10°F during the coldest months of winter.

Always keep in mind that USDA zone info for Madison is just an average and the actual date of last frost is different every year. Half of the time in Madison last frost occurs after April 15 so always be ready to cover your nasturtium if you have a surprise late frost.

USDA Zone Info for Madison

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Madison

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