The asparagus fern (Asparagus spp.) Is not a fern at all, but a member of the large lily (Liliaceae) plant family which includes daytime lilies and creamy asparagus which creates foliage similar to that of their asparagus fern. All varieties are classified as deer-resistant.
The asparagus fern is famous for its own stems and light airy needle-like foliage. Grown as a perennial in U.S. Department of Agriculture plant hardiness zones 9 to 11, it’s an evergreen with bright leaves which remain on the plant year-round. According to the University of California Marin Master Gardeners, all asparagus ferns have sharp thorns, which can be one reason that the plants are unattractive to deer. The thorns, which are actually the plant’s true leaves, which are much smaller and hardly noticeable on the Myers variety (Asparagus densiflorus ‘Myers”) also known as the Foxtail fern. Asparagus fern tolerates a broad range of soils, but grows best in a compost-rich medium ranked as pH neutral. The origins are composed of several tubers used from the plant to store food and moisture and also utilized to start new plants.
In USDA zones 9 to 11, asparagus ferns are grown outside year-round as background plantings to get different types of plants, as ground covers, in perennial gardens and in hanging pots. While they typically grow in hot sunny locations, they’re also suited to areas that get partial to full shade and suffer less drought harm in these locations. In colder climates, the ferns are grown mainly in pots which can be moved inside once the weather cools, even since they do not tolerate frost. Growing asparagus ferns in containers is one way to ensure they aren’t damaged by deer, as they can be held in safe locations and moved if needed.
Deer Resistance Ratings
Deer resistance evaluations are designed to help homeowners and gardeners determine what types of annuals, perennials and shrubs to plant which are likely to suffer harm from deer searching for food. Factors include texture and flavor, and while some plants are less attractive to deer, it is important to keep in mind that, if they’re hungry or thirsty enough, they’ll consume plants they normally wouldn’t eat at any other moment. So while no plant is completely deer resistant, you’re more likely to discourage them if you use just those plants they like least.
Other Asparagus Fern Varieties
Deer seek out plants with succulent leaves and stems which give them protein and moisture. They have a tendency to avoid plants such as asparagus ferns, with woody stems and small leaves. Asparagus densiflorus “Sprengeri” is actually the most common fern in this group as well as the hardiest. It tolerates cold temperatures and when left outside during winter, may produce poisonous bright red berries. Its long showy branches hang over the borders of planters and hanging baskets and it works well as the green foliage part in planters which also include vibrant flowering plants. The Plumosa fern (Asparagus setaceus) is far more delicate, but can rapidly become root-bound when container grown. The plants send out shoots that wrap themselves around anything they come into contact, and produce an airy appearance as they grow. Asparagus ferns may be left in the garden over the winter season in USDA zones 8 and 7 when their origins are well mulched.