One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Helena you can figure out when it's possible to plant dill by reviewing the USDA zone info.

Planting Calendar for Dill

Frost tolerance for dill:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Dill are barely cold tolerant which tells us that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant dill in Helena 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 dill and expect a good harvest is probably August. If you wait any later than that and your dill may not have a chance to fully mature. You can get started a few weeks earlier by starting your dill indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Helena. In the coldest months of winter you can expect an average low temperature of -25°F.

Always keep in mind 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 Helena and it will vary from year to year. Since half of the time in Helena you get a frost after May 15 be ready to protect your dill if you have a surprise late frost.

USDA Zone Info for Helena

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 Helena

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