When to Plant Lithospermum in Harlan, IA

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

The first opportunity to plant lithospermum in Harlan can be figured out by referring to the USDA zone info.


Planting Calendar for Lithospermum

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

It's probably not a good idea to plant lithospermum until after all chance of frost has passed because they do not do well in cold weather.

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

The earliest that you can plant lithospermum in Harlan 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 lithospermum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your lithospermum may not have a chance to grow to maturity. If you are starting your lithospermum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Harlan. In the coldest months of winter you should expect an average low temperature of -20°F.

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 Harlan and it is different every year. Half of the time in Harlan you get a frost after April 15 so just be sure to be ready to cover your lithospermum in the event of one of those late frosts.

USDA Zone Info for Harlan

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 Harlan

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