When to Plant Cosmos in Lansdowne, PA

One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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.

You should be able to determine when you can plant cosmos by reviewing the USDA zone info for Lansdowne.


Planting Calendar for Cosmos

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

Since cosmos are barely cold tolerant 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 cosmos
Possibly ok, but a risky time to plant cosmos
Probably not a good time to plant cosmos

The earliest that you can plant cosmos in Lansdowne 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 cosmos and expect a good harvest is probably August. If you wait any later than that and your cosmos may not have a chance to really do well. If you are starting your cosmos indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Lansdowne. In the coldest months of winter you should expect an average low temperature of 0°F.

Just be sure to remember that USDA zone info for Lansdowne is not always accurate and the actual date of last frost is different every year. Since half of the time in Lansdowne last frost occurs after April 15 be ready to protect your cosmos if you have a late frost.

USDA Zone Info for Lansdowne

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 Lansdowne

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