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

By using the USDA zone info for Boulder you will be able to determine when to plant nemesia.

Planting Calendar for Nemesia

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

Since nemesia require warm weather it's necessary to wait until after the last frost before you can plant them.

The earliest that you can plant nemesia 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 nemesia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your nemesia may not have a chance to grow to maturity. You can get started a little bit earlier by starting your nemesia indoors.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Boulder and it will vary from year to year. Since half of the time in Boulder there is a last frost after April 15 be ready to protect your nemesia 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.