The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant dahlia in Marshalltown should be estimated by checking out the USDA zone info.

Planting Calendar for Dahlia

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

It's a bad idea to plant dahlia until after the last frost has passed because they require warm weather.

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

Last Frost Date

In Marshalltown the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Remember that USDA zone info for Marshalltown may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Marshalltown there is a last frost after April 15 so make sure that you are ready to cover your dahlia if you have a late frost.

USDA Zone Info for Marshalltown

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 Marshalltown

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