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.

A common way of determining when it's the best time to plant diascia is to look at the USDA zone info for Madison.

Planting Calendar for Diascia

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

Diascia can survive in moderate cold which means that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant diascia in Madison 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 diascia and expect a good harvest is probably August. If you wait any later than that and your diascia may not have a chance to grow to maturity. If you are starting your diascia indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Madison. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Madison and it will vary from year to year. Half of the time in Madison last frost occurs after May 15 so make sure that you are ready to protect your diascia if you have a late frost.

USDA Zone Info for Madison

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 Madison

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