Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Norristown you can determine when it's the best time to plant salpiglossis by reviewing the USDA zone info.

Planting Calendar for Salpiglossis

Frost tolerance for salpiglossis:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Salpiglossis require warm weather which tells us that it is important to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant salpiglossis in Norristown is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant salpiglossis and expect a good harvest is probably August. Any later than that and your salpiglossis may not have a chance to grow to maturity. If you are starting your salpiglossis indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Norristown the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Norristown is an average the actual date of last frost is different every year. Half of the time in Norristown you get a frost after April 15 so be sure to be ready to cover your salpiglossis if you have one of those late frosts.

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 Low	0°F
Highest Expected Low	5°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.