One of the first steps you take when you are estimating your gardening schedule is find your 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.

A common way of getting a good idea when to plant sweet peas is to consult the USDA zone info for Waterloo.

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.

Since sweet peas are barely cold tolerant you can plant them slightly earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant sweet peas in Waterloo 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. Any later than that and your sweet peas may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your sweet peas indoors.

Last Frost Date

In Waterloo the average date of last frost happens on April 15. It might get as low as -20°F during the coldest months of winter.

Always keep in mind that USDA zone info for Waterloo is just an average and the actual date of last frost will vary from year to year. Since half of the time in Waterloo it frosts late in the year after April 15 be ready to protect your sweet peas in the event of a late frost.

USDA Zone Info for Waterloo

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Waterloo

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