One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant salpiglossis in Phoenix can be estimated by looking at the USDA zone info.

Planting Calendar for Salpiglossis

Frost tolerance for salpiglossis:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant salpiglossis until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant salpiglossis in Phoenix 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 little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Phoenix. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Phoenix is just an average the actual date of last frost will vary from year to year. Since half of the time in Phoenix last frost occurs after March 15 be ready to protect your salpiglossis in the event of one of those late frosts.

USDA Zone Info for Phoenix

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Phoenix

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