The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant pincushion flower in Zone 4a should be figured out by using the USDA zone info.

Planting Calendar for Pincushion Flower

Frost tolerance for pincushion flower:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Pincushion Flower do well in moderate cold which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant pincushion flower in Zone 4a 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 pincushion flower and expect a good harvest is probably August. You probably don't want to wait any later than that or else your pincushion flower may not have a chance to really do well. If you are starting your pincushion flower indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Zone 4a the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Zone 4a and it will vary from year to year. Since half of the time in Zone 4a you get a frost after May 15 be ready to cover your pincushion flower if you have one of those late frosts.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in your other planting guides for Zone 4a.