Prevent deer from eating plants in San Antonio neighborhoods


As anyone who has deer in their neighborhood has witnessed, the animals are unpredictable about what plants they eat. Deer in some neighborhoods eat plants that deer in other neighborhoods don’t. Deer are also curious and prone to tasting newly placed plants. But tasting is the result of more than curiosity.

Plants that have come straight from the nursery to your landscape are not as strong chemically as plants that have been in the garden longer. The new plants have recently received heavy fertilization and watering, so they have more nitrogen and water in their foliage and stems, and fewer chemicals that deter deer from eating them.

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Eventually, chemical structures and balances give plants tastes that deer don’t like, but at planting time their chemistry is less potent. There’s a tactic that helps bridge the gap between lush but bland new transplants and their eventual strong taste to discourage deer from eating them: apply a deer repellent, like Liquid Fence, at planting and at least once a week after planting. Some horticulturists recommend increasing application to twice a week for at least six weeks.

Liquid Fence spray works especially well on newly planted salvia, lantana and iris, all of which are plants that are not generally deer food except when first planted. Liquid Fence can also temporarily discourage deer from consuming plants they typically like to eat, but the protection doesn’t last long.

• Rain will stimulate the growth of new foliage on seedlings of blueberry, hackberry and other undesirable species in your landscape. Prune them from your garden beds and fences. If you immediately apply Cut Vine and Stump Killer to the root side of the stem, it will prevent regrowth.

• If you have decided not to apply a pre-emergence herbicide to your lawn to prevent the germination of winter weeds, you can achieve reasonable control if you mow them weekly. Rescue grass and annual bluegrass weeds are attractive when mowed to seed in the spring.

• It’s time to prepare your garden and start planting fall and winter vegetables. Select your favorite vegetables from the nursery’s seed trays and transplant trays, but before you plant anything, apply 2 inches of compost and 10 cups of “winterizer” or slow-release lawn fertilizer each 100 square feet of bed. It is also important to irrigate the bed before planting.

• Blooming zinnias, mistflowers, porterweeds, lantanas, salvias, Mexican marigolds, firebushes, Durantas, esperanzas, thyrallis, and poincianas will provide nectar for fall-migrating monarchs and others butterflies. Flowering plants can go straight from the nursery to your landscape in a container or in the garden.

Plants that deer do not usually eat include vinca, angelonia, milkweed, marigold, and mint, as well as lantana, salvia, and iris.

Although milkweed is generally deer-proof, it is unclear whether Liquid Fence would interfere with milkweed’s use as a source of butterfly nectar if sprayed during spring migration visits and Fall Monarch Festival in San Antonio. I didn’t use Liquid Fence on it, although the deer will taste and tear off the newly planted milkweed.

Texas mountain laurel, viburnum, thyrallis, and yaupon holly, both dwarf and standard, do not appear to be eaten by deer. The dwarf Chinese holly has also been discontinued, but the rest of the hollies, including Burford, are eaten in my neighborhood. Esperanza, poinciana and pomegranate are not eaten in my neighborhood, but we have received reports that they have been eaten in other neighborhoods. Nandina is another shrub that seems to survive in neighborhoods with deer, but is partially eaten during droughts.

Of the smaller trees, the Mexican plum is on many deer-proof lists. However, most trees should be protected from males rubbing their antlers on them, even if deer do not eat them. Friction will permanently injure the vascular system on shade trees or even break the plant down to the ground on crepe myrtle and similar small or newly planted trees.

Plan to protect a newly planted tree for several years by wrapping the trunk with wire mounted on metal fence posts. The fence should be 6 feet in diameter or 6 feet high to prevent the bucks from rubbing against the trunk and to prevent any deer from feeding on the leaves and branches. Deer eat most species of young trees.

Calvin Finch is a retired Texas A&M horticulturist.


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