Mexican petunias

by Deborah Pack
(Stephenville, Texas, USA)

Ruellia simplex, The Mexican Petunia

We live in central Texas. Should the Mexican Petunias be in a green house during the freezing temps and snow or will they be fine left out in the yard?

Comments for Mexican petunias

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Nov 06, 2018

Anything that says Mexican in the name
by: Jacki Cammidge, Certified Horticulturist

You can safely assume that the plant in question is not that cold hardy. Ruellia simplex, or Mexican petunia is a perennial plant originating in Mexico and is hardy to zone 8 to 11. Look up your plant hardiness zone if you're not sure what it is.

Common names include Mexican bluebell, hardy petunia, wild petunia, Britton’s wild petunia and perennial petunia.

Mexican petunias are able to tolerate a wide range of growing conditions but prefer wet or marshy soils, such as moist woodlands or the edges of ponds and lakes. They can withstand drought and even full sun in drier soils.

These plants are classed as an invasive species in some areas, and can self-seed mercilessly.

Invasive Mexican petunias form large, horizontal roots that grow above and below ground, making them difficult to remove, and even small pieces that are overlooked can regrow. There is also a gel that forms on these rhizomes that helps them stick to the soil, making it impossible to remove them.

Seed capsules on the plants burst open when ripe, scattering seeds everywhere. The seeds can remain in the soil and germinate years after the plants have been eradicated.

I would maybe see if you can get some seeds or start some cuttings to take indoors, and see if the adult plants are tough enough to survive outside where you are if you're still keen on keeping this type of invasive plant going.

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