Ask Mr. Smarty Plants

The Houston Chapter of the Native Plant Society of Texas (NPSOT) has an excellent Native Plant Guide with recommendations for all sorts of plants and plant suppliers.   Here are a few from their Guide that should work for you.   I have checked the ones I picked against several poisonous plant databases for their toxicity.  These databases are:

• Poisonous Plants of North Carolina
• Toxic Plants of Texas
• University of Pennsylvania Poisonous Plants Page
• Canadian Poisonous Plants Information System
• ASPCA Toxic and Non-Toxic Plant List - Dogs

The allergy information is a little harder to find since allergies are an individual reaction to the particular allergen rather than a general reaction to a toxic substance.   However, PollenLibrary.com has a searchable database of more than 1200 plants with information about the severity of allergies to their pollen.   The database can be searched by common or Latin name.   I suggest you use the Latin name for searching any plant database since common names of plants can be quite variable.

Now, here are some plants that I found in the Houston Native Plant Guide that meet most of your criteria:

Lonicera sempervirens (Coral honeysuckle) is a native evergreen vine with red blossoms that attract butterflies and hummingbirds.   It is not listed on any of the above poisonous plant databases.  PollenLibrary.com lists it as a mild allergen.

Bignonia capreolata (Crossvine) is a semi-evergreen vine also attractive to hummingbirds and butterflies.  It is not listed as toxic or as an allergen.

Polystichum acrostichoides (Christmas fern) is an evergreen fern that grows in the Houston area.  It is listed as non-toxic to dogs on the ASPCA list and not listed on any of the other above poisonous plant databases or in the PollenLibrary.com database.  It needs shade or partial shade to grow, as well as moist soil.

Morella cerifera (Wax myrtle) is an evergreen shrub that grow into a small tree.  It is not listed on any of the above poisonous plant databases, but is listed by PollenLibrary.com as a mild allergen.

Cyrilla racemiflora (Swamp titi) is semi-evergreen in the Houston area and is not found on any of the poisonous plant databases above or in the PollenLibrary.com database.  It will eventually grow into a small tree and, as its common name suggests, will grow in wet places.

Sabal minor (Dwarf palmetto) is a small evergreen palm that is not on any of the poisonous plant databases but is listed as a mild allergen in the PollenLibrary.com database.

Malvaviscus arboreus var. drummondii (Turk's cap or turkscap) is a perennial that, although not evergreen, will retain some of its green leaves in mild winters.  It's not on any of the poisonous databases or in the in the PollenLibrary.com database.

You can also check our Texas—South Recommended page for more options.