When to Plant Hollyhocks in Swarthmore, PA

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

It's possible to figure out when to plant hollyhocks by looking at the USDA zone info for Swarthmore.


Planting Calendar for Hollyhocks

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

Hollyhocks do ok in some cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant hollyhocks
Possibly ok, but a risky time to plant hollyhocks
Probably not a good time to plant hollyhocks

The earliest that you can plant hollyhocks in Swarthmore 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 hollyhocks and expect a good harvest is probably September. Any later than that and your hollyhocks may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your hollyhocks indoors.

Last Frost Date

On average the last frost is on April 15 in Swarthmore. 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 may not be accurate from year to year because it is based on the USDA zone info for Swarthmore and it is different every year. Since half of the time in Swarthmore there is a last frost after April 15 be ready to protect your hollyhocks if you have one of those late frosts.

USDA Zone Info for Swarthmore

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 Low0°F
Highest Expected Low5°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 Swarthmore

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