The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

One way of getting a good idea when it's the best time to plant skullcap is to look at the USDA zone info for Merrillville.

Planting Calendar for Skullcap

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

You really shouldn't plant skullcap until after the last frost has passed because they do not do well in cold weather.

The earliest that you can plant skullcap in Merrillville 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. Any later than that and your skullcap may not have a chance to grow to maturity. You can get started a little bit earlier by starting your skullcap indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Merrillville. In the coldest months of winter you can expect an average low temperature of -15°F.

Since the USDA zone info for Merrillville is just an average the actual date of last frost will vary from year to year. Half of the time in Merrillville last frost occurs after April 15 so make sure that you are prepared to protect your skullcap if you have a surprise late frost.

USDA Zone Info for Merrillville

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Merrillville

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