When to Plant Lithospermum in Happy Valley, OR

One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant lithospermum in Happy Valley can be estimated by using the USDA zone info.


Planting Calendar for Lithospermum

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

You really shouldn't plant lithospermum until after all chance of frost has passed because they are not cold tolerant.

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 Happy Valley 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. Any later than that and your lithospermum may not have a chance to fully mature. Starting your lithospermum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Happy Valley the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Happy Valley is just an average the actual date of last frost changes from year to year. Half of the time in Happy Valley it frosts late in the year after March 15 so make sure that you are ready to protect your lithospermum in the event of a surprise late frost.

USDA Zone Info for Happy Valley

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)March 15
Average Date of First Frost (fall)November 15
Lowest Expected Low15°F
Highest Expected Low20°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 20°F.

Plants to Grow in Happy Valley

You may be interested in your other planting guides for Happy Valley.