When to Plant Alstromeria in Swarthmore, PA

One of the first steps you take when you are determining 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.

The first chance to plant alstromeria in Swarthmore should be estimated by checking out the USDA zone info.


Planting Calendar for Alstromeria

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

You can plant alstromeria a little earlier in the year because they do well in moderate cold.

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

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

Last Frost Date

In Swarthmore 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 not always accurate because it is based on the USDA zone info for Swarthmore and it changes from year to year. Half of the time in Swarthmore you get a frost after April 15 so always be ready to cover your alstromeria in the event of 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.