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.

One way of making a decision about when to plant snapdragons is to consult the USDA zone info for Boulder.

Planting Calendar for Snapdragons

Frost tolerance for snapdragons:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Snapdragons are moderately cold tolerant which means that you can start planting them earlier than more sensitive plants.

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

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

Last Frost Date

In Boulder the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

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 Boulder and it will vary from year to year. Half of the time in Boulder last frost occurs after April 15 so make sure that you are ready to cover your snapdragons 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.