Ask Mr. Smarty Plants

First, let me tell you which trees are not safe to plant around horses.  Avoid all Quercus species (oaks) and Prunus species (plums, peaches, cherries, apricots, etc.).  Also, do not plant Acer rubrum (scarlet maple) or any Acer species—see Toxic Plants of Texas.  Most pine species are not listed on any toxic plant database, but Pinus ponderosa (Ponderosa pine) does appear on several of the databases below and should not be planted near cattle or horses.

Now, here are some trees native to Shasta County that are safe and will provide shade for them:

Fraxinus dipetala (California ash) is a small deciduous tree (up to 20 feet) with fragrant white flowers.  Here are photos and more information.

Populus fremontii (Fremont cottonwood) is fast-growing and grows to 60 feet, but it does like moderate water.  Female plants produce cotton (the seeds), male plants do not.  The 'Nimbus' variety is male.  Here are more photos and information.

Platanus racemosa (California sycamore) grows fast and can reach 30 to 80 feet, but will need water until established.  Here are more photos and information.

Cercis orbiculata [syn. Cercis occidentalis var. orbiculata] (California redbud) is a small tree (up to 15 feet) with pink blossoms in the spring.  Here are more photos and information.

Umbellularia californica (California laurel) is evergreen and a slow-grower to 40 feet.  Here are more photos.

Abies concolor (Balsam fir) is evergreen and grows 50 to 150 feet high.

Cornus nuttallii (Pacific dogwood) grows 15 to 40 feet high and has showy flowers.

Here are databases that you can use to check on toxicity of plants to horses and other animals:

ASPCA's Toxic and Non-Toxic Plant List - Horses  [Note:  The first list is for plants toxic to horses and the second list is for plants non-toxic to horses.]

Horse Nutrition: Poisonous Plants from Ohio State University Extension Service

10 Most Poisonous Plants for Horses from Equisearch

California Poison Control System

Pennsylvania's Poisonous Plants from the Universtiy of Pennsylvania

Cornell University Plants Poisonous to Livestock

Toxic Plants of Texas

Poisonous Plants of North Carolina

Canadian Poisonous Plants Information System

Here are photos from our Image Gallery of some of the plants listed above:

Populus fremontii

Platanus racemosa

Cercis orbiculata

Umbellularia californica

Abies concolor

Cornus nuttallii