Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In New Castle you can determine when to plant primula by referring to 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 are one of those plants that can tolerate quite a bit of cold weather you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant primula in New Castle 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 fully mature. Starting your primula indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In New Castle the average date of last frost happens on April 15. You should expect an average low temperature of 0°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for New Castle and it is different every year. Since half of the time in New Castle you get surprised by a frost after April 15 be ready to cover your primula if you have one of those late frosts.

USDA Zone Info for New Castle

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 New Castle

You may be interested in your other planting guides for New Castle.