When to Plant Skullcap in Altoona, IA

One of the best tools that you have as gardeners to help us estimate 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 first chance to plant skullcap in Altoona should be estimated by reviewing the USDA zone info.


Planting Calendar for Skullcap

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

Since skullcap require warm weather you must wait until after the last frost before you can plant them.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant skullcap
Possibly ok, but a risky time to plant skullcap
Probably not a good time to plant skullcap

The earliest that you can plant skullcap in Altoona 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 skullcap and expect a good harvest is probably August. If you wait any later than that and your skullcap may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your skullcap indoors.

Last Frost Date

The average date of last frost is April 15 in Altoona. It might get as low as -20°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Altoona and it will vary from year to year. Since half of the time in Altoona it frosts late in the year after April 15 be ready to cover your skullcap if you have a surprise late frost.

USDA Zone Info for Altoona

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 Altoona

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