Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant rudbeckia in Helena should be determined by using the USDA zone info.

Planting Calendar for Rudbeckia

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

You can plant rudbeckia just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant rudbeckia in Helena is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant rudbeckia and expect a good harvest is probably September. If you wait any later than that and your rudbeckia may not have a chance to grow to maturity. If you are starting your rudbeckia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Helena. It might get as low as 10°F during the coldest months of winter.

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Helena and it changes from year to year. Since half of the time in Helena there is a last frost after March 15 be ready to cover your rudbeckia if you have a surprise late frost.

USDA Zone Info for Helena

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Helena

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