One of the first steps you take when you are making a decision about 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.

In Boulder you can figure out when it's the best time to plant salvia by reviewing the USDA zone info.

Planting Calendar for Salvia

Frost tolerance for salvia:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since salvia are barely cold tolerant you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant salvia in Boulder is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant salvia and expect a good harvest is probably August. If you wait any later than that and your salvia may not have a chance to grow to maturity. Starting your salvia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

Since the USDA zone info for Boulder may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Boulder there is a last frost after April 15 be ready to cover your salvia in the event of a surprise late frost.

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.