One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 best time to plant tropical water plants in Sonora can be determined by using the USDA zone info.

Planting Calendar for Tropical Water Plants

Frost tolerance for tropical water plants:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Tropical Water Plants are not cold tolerant which means that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant tropical water plants in Sonora 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 tropical water plants and expect a good harvest is probably September. Any later than that and your tropical water plants may not have a chance to fully mature. Starting your tropical water plants indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Sonora is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Sonora last frost occurs after February 15 be ready to cover your tropical water plants if you have a late frost.

USDA Zone Info for Sonora

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 Sonora

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