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.

The earliest that you can plant melampodium in Johnston can be figured out by looking at the USDA zone info.

Planting Calendar for Melampodium

Frost tolerance for melampodium:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

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

The earliest that you can plant melampodium in Johnston 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 melampodium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your melampodium may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your melampodium indoors.

Last Frost Date

The average date of last frost is April 15 in Johnston. You can expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Johnston and it will vary from year to year. Half of the time in Johnston there is a last frost after April 15 so just be sure to be ready to cover your melampodium in the event of a late frost.

USDA Zone Info for Johnston

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 Johnston

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