One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Tulsa you can determine when it's the best time to plant primula by using the USDA zone info.

Planting Calendar for Primula

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

Since primula do well in cold you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant primula in Tulsa 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. You probably don't want to wait any later than that or else your primula may not have a chance to really do well. Starting your primula indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Tulsa the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Tulsa is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Tulsa you get surprised by a frost after April 15 so just be sure to be ready to protect your primula if you have a surprise late frost.

USDA Zone Info for Tulsa

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Tulsa

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