One of the first steps you take when you are estimating 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 USDA zone info for Royal Oak should be reviewed to figure out when to plant salpiglossis.

Planting Calendar for Salpiglossis

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

Salpiglossis are not cold tolerant which tells us that it's necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant salpiglossis in Royal Oak 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. If you wait any later than that and your salpiglossis may not have a chance to grow to maturity. Starting your salpiglossis indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Royal Oak. It might get as low as -10°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Royal Oak and it can change quite a bit from year to year. Since half of the time in Royal Oak you get a frost after April 15 be ready to cover your salpiglossis if you have a late frost.

USDA Zone Info for Royal Oak

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Royal Oak

You may be interested in your other planting guides for Royal Oak.