Ask Mr. Smarty Plants

We are assuming that the "Bubba" is a name given to  Chilopsis linearis (desert willow) by a nursery retailer. This USDA Plant Profile shows that it is native in the area of Kendall County, and will probably do fine in Boerne. We don't know if horses will eat them; we do know that the horse is a herbivore and a grazing animal. Mostly they eat grass and hay, which is dried grass. Given their size, horses have small stomachs designed to process small amounts of food continuously. Horses will also eat stray foliage, like leaves and branches. So, this probably means they would eat the desert willow, if it was available, and it might not hurt the horse, but it would sure mess up those beautiful blooms on the plant. Given the choice, we would separate horses and desert willows, for the sake of the plants. 

We have checked all of the poison plant databases listed below, and none of them list Chilopsis linearis (desert willow).

Poisonous Plants of North Carolina

Cornell University Plants Poisonous to Livestock

Toxic Plants of Texas 

University of Pennsylvania Poisonous Plants

Canadian Poisonous Plants Information System

Horse Nutrition: Poisonous Plants from Ohio State University

10 Most Poisonous Plants for Horses from EquiSearch.com

Poisonous Plants from Trailblazer Magazine

Toxic Plants: Horses from the ASPCA

Because the desert willow does not appear on any of these lists does not guarantee it not to harm horses, but it reduces the possibility. 

Chilopsis linearis

Chilopsis linearis

Chilopsis linearis

Chilopsis linearis