When to Plant Primula in Milliken, CO

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.

It's a good idea to estimate when to plant primula by referring to the USDA zone info for Milliken.


Planting Calendar for Primula

Frost tolerance for primula: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Primula are very cold tolerant which means that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant primula
Possibly ok, but a risky time to plant primula
Probably not a good time to plant primula

The earliest that you can plant primula in Milliken 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 primula and expect a good harvest is probably September. Any later than that and your primula may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your primula indoors.

Last Frost Date

The average date of last frost is April 15 in Milliken. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Milliken and it will vary from year to year. Half of the time in Milliken you get a frost after April 15 so always be ready to cover your primula in the event of a surprise late frost.

USDA Zone Info for Milliken

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 Milliken

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