One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

By checking out the USDA zone info for Westminster you will be able to determine when you can plant trifolium.

Planting Calendar for Trifolium

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

Trifolium do ok in moderate cold which means that you can start planting them slightly earlier than more sensitive plants.

The earliest that you can plant trifolium in Westminster 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 trifolium and expect a good harvest is probably August. You probably don't want to wait any later than that or else your trifolium may not have a chance to fully mature. If you are starting your trifolium indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Westminster. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Westminster is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Westminster it frosts late in the year after April 15 be ready to protect your trifolium in the event of one of those late frosts.

USDA Zone Info for Westminster

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 Westminster

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