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.

You should be able to determine when you can plant sweet peas by looking at the USDA zone info for New Castle.

Planting Calendar for Sweet Peas

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

Sweet Peas do ok in very little cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant sweet peas in New Castle 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 sweet peas and expect a good harvest is probably August. You probably don't want to wait any later than that or else your sweet peas may not have a chance to grow to maturity. If you are starting your sweet peas indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Keep in mind that USDA zone info for New Castle is just an average and the actual date of last frost can change quite a bit from year to year. Half of the time in New Castle last frost occurs after April 15 so always be ready to protect your sweet peas if you have a late frost.

USDA Zone Info for New Castle

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 New Castle

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