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.

By looking at the USDA zone info for Humble you should be able to figure out when it's the best time to plant zinnia.

Planting Calendar for Zinnia

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

Zinnia are not cold tolerant which tells us that it's necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant zinnia in Humble 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 zinnia and expect a good harvest is probably September. You probably don't want to wait any later than that or else your zinnia may not have a chance to really do well. Starting your zinnia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Humble the average date of last frost happens on February 15. You should expect an average low temperature of 20°F in the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Humble and it can change quite a bit from year to year. Half of the time in Humble you get a frost after February 15 so make sure that you are ready to cover your zinnia if you have one of those late frosts.

USDA Zone Info for Humble

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Humble

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