One of the best tools that you have as gardeners to help us determine 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.

You can figure out when it's the best time to plant scaevola in Boulder by checking out the USDA zone info.

Planting Calendar for Scaevola

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

You really shouldn't plant scaevola until after the last frost because they require warm weather.

The earliest that you can plant scaevola in Boulder 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 scaevola and expect a good harvest is probably August. If you wait any later than that and your scaevola may not have a chance to really do well. Starting your scaevola indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Boulder. You should expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that USDA zone info for Boulder is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Boulder you get a frost after April 15 so make sure that you are ready to protect your scaevola in the event of one of those late frosts.

USDA Zone Info for Boulder

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 Boulder

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