When to Plant Alyssum in Norristown, 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 earliest that you can plant alyssum in Norristown should be estimated by using the USDA zone info.


Planting Calendar for Alyssum

Frost tolerance for alyssum: Very tolerant of frost.
When to plant: Up to 7 weeks before last frost.

Alyssum do well in quite a bit of cold which means that you can plant them much earlier in the year than more sensitive plants.

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

The earliest that you can plant alyssum in Norristown 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 alyssum and expect a good harvest is probably September. Any later than that and your alyssum may not have a chance to grow to maturity. Starting your alyssum indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Norristown. In the coldest months of winter you should expect an average low temperature of 0°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Norristown and it will vary from year to year. Half of the time in Norristown you get a frost after April 15 so make sure that you are ready to protect your alyssum in the event of a surprise late frost.

USDA Zone Info for Norristown

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 Norristown

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