Asters land in the “moderately resistant” category for deer and the “occasionally browsed” category for rabbits, which in practical terms means they are far from a guaranteed meal for wildlife but not completely safe either. Gardeners in high-pressure deer zones should treat asters as a better bet than hostas or tulips, but not as bulletproof as lavender or daffodils. The picture gets more complicated when you account for the enormous variety of plants sold under the “aster” label, since some species hold up considerably better than others.
What Field Research Shows About Deer and Asters
Direct experimental data on deer browsing of asters in controlled settings is surprisingly thin, but one multi-year forest study offers a useful window. Researchers planted seedlings of five native species with varying functional traits into plots where white-tailed deer either had free access or were excluded by fencing. Aster seedlings (specifically calico aster, now classified as Symphyotrichum lateriflorum) showed intermediate survival at about 76%, falling between the hardiest species like sedge at 98% and the most vulnerable, bellwort, at 42%.
1Forest Ecology and Management. Do white-tailed deer and the exotic plant garlic mustard interact to affect the growth and persistence of native forest plants?What stands out is that the deer-access treatment did not significantly depress survival or growth in the aster seedlings the way it did in other species. Deer browsing reduced survival and branching in bellwort, slowed growth in wild geranium and red oak, and altered tillering in sedge, but asters were not listed among the species where deer access produced measurable damage. The researchers noted that the deer and garlic mustard treatments only significantly affected survival in bellwort, which may reflect the limited variation in survival across the other species but also suggests asters were not a preferred target when other foliage was available.1Forest Ecology and Management. Do white-tailed deer and the exotic plant garlic mustard interact to affect the growth and persistence of native forest plants?
This is consistent with what most extension services and deer-browse lists report: asters are “seldom severely damaged” or “rarely a first choice.” But the 76% survival figure is a reminder that some asters will get eaten, especially where deer pressure is heavy and preferred food is scarce.
Chemical Compounds That May Deter Browsers
Plants in the aster family produce a range of volatile compounds in their foliage, and some of these likely play a role in making the plants less appealing to herbivores. An analysis of the essential oils in a related species, Symphyotrichum squamatum, found that sesquiterpenes dominated the chemical profile, making up roughly 70% to nearly 89% of the oil depending on the habitat where the plant was growing. The major individual compounds included humulene epoxide, spathulenol, caryophyllene oxide, germacrene D, and alpha-humulene.2Arabian Journal of Chemistry. Chemical composition variations, allelopathic, and antioxidant activities of Symphyotrichum squamatum (Spreng.) Nesom essential oils growing in heterogeneous habitats
Sesquiterpenes are known in plant biology as defensive chemicals. They contribute bitter or astringent flavors and pungent aromas that many mammals find unappealing. Plants with high sesquiterpene loads in their leaves tend to be nibbled less than those without them. This does not make asters toxic to deer or rabbits; it just means the foliage tastes worse than a lot of alternatives. When a deer walks through a garden with roses, hostas, and asters, the asters are often the last thing on the menu.
The chemical profile also varied between plants growing in coastal versus inland habitats, which hints at why aster resistance can seem inconsistent. Plants under different growing conditions produce different concentrations and mixtures of these defensive oils. An aster growing in rich, moist garden soil might have a different chemical profile from one growing in dry, lean conditions, and that difference could affect how attractive it is to browsers.
Why “Resistant” Does Not Mean “Proof”
The single biggest misconception about deer-resistant plants is that the label means animals will never touch them. In reality, “deer resistant” is a spectrum, and almost every plant on every resistance list comes with fine print. Deer behavior changes with season, population density, and food availability. During a mild autumn when acorns and wild browse are plentiful, your asters might go untouched for years. During a harsh late winter when natural food is stripped bare, those same deer will eat plants they normally ignore.
Several factors push asters from “rarely browsed” toward “sometimes damaged”:
- New growth: Young aster shoots in spring are softer, more succulent, and less loaded with defensive compounds than mature foliage. If deer or rabbits are going to eat asters, this is when it usually happens.
- High local deer density: In suburban areas where deer populations have exploded and natural habitat is fragmented, the “seldom damaged” label breaks down. Deer under pressure will eat almost anything.
- Lush, fertilized gardens: Research on herbivore communities has shown that nitrogen fertilization significantly improves browse quality and that herbivores actively select fertilized vegetation over unfertilized controls. In one study, both moose and hares left more feeding signs in fertilized plots.3Journal of Applied Ecology. Response of a herbivore community to increased food quality and quantity: an experiment with nitrogen fertilizer in a boreal forest A heavily fertilized garden bed of asters, lush with nitrogen-rich foliage, can become more attractive to browsers than a leaner planting would be.
- Isolated plantings: A single aster clump in a sea of lawn gives deer and rabbits fewer choices. The resistance advantage only works when better food options are available nearby.
The flip side is that you can increase the effective resistance of your asters by managing some of these variables. Leaner soil, companion planting with strongly aromatic herbs, and situating asters away from known deer trails all shift the odds in your favor.
How Rabbits Differ from Deer
Rabbits present a different challenge than deer for aster growers, and the distinction matters for how you protect your plants. Deer browse from the top down, stripping leaves and nipping flower buds and stems. Rabbits work from the ground up, chewing through stems at or near ground level, which can kill young plants outright even if the damage looks minor.
Eastern cottontails and other common garden rabbits do eat asters, but they tend to be more selective than deer about which parts they target and more deterred by fuzzy or rough-textured foliage. Aster species with hairy stems and leaves, like New England aster (Symphyotrichum novae-angliae), get less rabbit attention than smooth-leaved types. The dense, wiry stems of mature aster clumps also seem to discourage rabbits compared to soft, floppy growth.
Rabbit damage to asters is most common in early spring when new shoots are tender and there is little else growing, and again in late fall when rabbits are stocking up on whatever remains green. Established aster clumps with thick root systems can usually recover from moderate rabbit browsing, but newly planted divisions or seedlings are vulnerable. If you are dealing with rabbits specifically, a short wire cage around new transplants for their first growing season is often enough protection.
Which Aster Species Hold Up Best
The word “aster” covers a wide range of plants, and their resistance to browsing varies enough to matter when you are choosing what to plant. In North America, most plants sold as asters in garden centers belong to the genus Symphyotrichum, though older references and many plant tags still use the name Aster. True Aster species (like Aster amellus) are mostly European and Asian plants that behave somewhat differently in the garden.
Among the commonly grown North American species, some general patterns emerge:
- New England aster (S. novae-angliae): One of the most deer-resistant options. The stems and leaves are notably hairy and somewhat sticky, and the plants develop stiff, dense growth that deer tend to bypass. Rabbits also seem to find the texture unappealing.
- Aromatic aster (S. oblongifolium): The foliage has a strong, resinous scent when crushed, which correlates well with deer avoidance. This species is frequently listed as one of the most resistant asters and has the added benefit of being drought-tolerant.
- Smooth aster (S. laeve): Despite its name, the waxy, bluish foliage seems to be unappealing to deer. This species frequently shows up on “deer resistant native plants” lists from extension services.
- New York aster (S. novi-belgii): More frequently browsed than the species above. The softer foliage and more succulent stems make it a comparatively easier target. Many popular garden hybrids derive from this species, which is worth knowing when selecting cultivars.
- Calico aster (S. lateriflorum): The species used in the forest study mentioned earlier. Shows intermediate resistance. A fine garden plant, but not the one to lean on if deer pressure is your primary concern.
If you are shopping specifically for deer and rabbit resistance, prioritize species with hairy, rough-textured, or aromatic foliage. Smooth-leaved cultivars bred for large, showy flowers tend to be the ones that get eaten first.
Practical Protection Strategies
Even with a moderately resistant plant, gardeners in areas with heavy wildlife pressure often combine resistance with physical or scent-based deterrents. Here are the approaches that work best with asters specifically:
Scent repellents containing putrescent egg solids or capsaicin are the most widely recommended spray-on options. They need reapplication after rain and every few weeks during the growing season, which can be tedious for large plantings but works well for a few prominent aster clumps you want to protect through bloom. The key is to start applications early in the season before deer and rabbits develop a habit of visiting your garden.
Companion planting is less labor-intensive and can be quite effective. Surrounding asters with plants that deer strongly avoid, like catmint, Russian sage, lavender, or ornamental alliums, creates an aromatic barrier that makes the whole bed less inviting. Deer tend to avoid walking through a stand of strong-smelling plants to reach something only moderately appealing. This approach has limits in small gardens where deer can simply reach over companion plants, but it works well in larger borders.
Physical fencing is the only method that approaches certainty. Deer require fencing at least seven to eight feet tall, or shorter double-fence arrangements that exploit their reluctance to jump into a narrow space. For rabbits, a two-foot-tall fence of hardware cloth with the bottom buried a few inches into the soil is usually sufficient. Some gardeners install short rabbit fencing around the base of garden beds and rely on the asters’ natural resistance for the deer portion of the equation.
One underappreciated tactic is timing your cleanup. Leaving aster stalks standing through winter provides habitat for beneficial insects, but it also gives rabbits something to chew on during the lean months. If rabbit damage to aster crowns is a recurring problem, cutting stalks down in late fall and clearing debris from around the base of plants removes cover and food that attracts rabbits to the area.
The Aster Name Confusion
If you have ever looked up deer resistance for asters and found contradictory information, part of the problem is taxonomic. In the early 2000s, botanists reclassified most North American asters out of the genus Aster and into Symphyotrichum, Eurybia, Doellingeria, and several other genera. The European and Asian species kept the Aster name. This means that a deer-resistance list compiled before 2005 that says “Aster” might be referring to plants now called Symphyotrichum, and a newer list that says “Aster” might be referring only to the European species.
The forest ecology study cited earlier captures this nicely, listing its test species as “Aster lateriflorus/Symphyotrichum lateriflorum” with both old and new names.1Forest Ecology and Management. Do white-tailed deer and the exotic plant garlic mustard interact to affect the growth and persistence of native forest plants? When checking any browse-resistance list, pay attention to whether it uses the old or new naming convention, and try to match the actual species rather than just the common name. “Aster” at your local nursery almost certainly means a Symphyotrichum species if you are in North America.
When Growing Conditions Change the Equation
The finding that herbivores actively seek out nitrogen-rich vegetation has direct implications for how you grow asters if deer and rabbits are a concern.3Journal of Applied Ecology. Response of a herbivore community to increased food quality and quantity: an experiment with nitrogen fertilizer in a boreal forest Asters, as a group, do not need or particularly want heavy fertilization. Most species are native to meadows, prairies, and woodland edges with lean to moderate soil. Gardeners who push asters with regular fertilizer often end up with tall, floppy plants that require staking and that happen to be more attractive to browsers.
Backing off on nitrogen and letting asters grow in conditions closer to their natural habitat produces sturdier, more compact plants with tougher foliage and, likely, a higher concentration of defensive compounds in the leaves. This is one of the rare situations in gardening where doing less work produces better results on multiple fronts: less fertilizer means less flopping, less staking, and less browsing.
Water availability matters too, though less directly. Drought-stressed asters can become more vulnerable because damaged or wilted foliage triggers a cascade of chemical changes that sometimes reduce the bitter compounds deer dislike. Consistent moderate watering, enough to keep plants healthy but not lush, hits the sweet spot. Aromatic aster and smooth aster are good choices for drier sites because they tolerate lean, dry conditions without the stress response that makes other species more palatable.
Soil pH and mineral content also influence the chemical makeup of aster foliage, though the practical implications for deer resistance are hard to pin down with precision. The variation in essential oil composition observed in Symphyotrichum squamatum between coastal and inland habitats, where sesquiterpene profiles shifted substantially depending on growing conditions, suggests that the same cultivar could be more or less resistant depending on where and how it is grown.2Arabian Journal of Chemistry. Chemical composition variations, allelopathic, and antioxidant activities of Symphyotrichum squamatum (Spreng.) Nesom essential oils growing in heterogeneous habitats This is one reason anecdotal reports about deer and asters can be so contradictory: two gardeners growing the same variety in different soil and light conditions might have genuinely different experiences with wildlife damage.
Other Wildlife That Targets Asters
Deer and rabbits get the most attention, but they are not the only animals that eat asters. Groundhogs (woodchucks) are enthusiastic consumers of aster foliage and will mow down entire plants during their growing season. Unlike deer, which tend to nip selectively, groundhogs eat systematically and can destroy a planting quickly. If your aster damage includes stems chewed cleanly at a consistent height of a few inches and the damage is concentrated at the garden’s edge near a burrow, groundhogs are the more likely culprit.
Voles can damage asters from below, gnawing on roots and crowns during winter, particularly under mulch or snow cover. This type of damage shows up as plants that fail to emerge in spring or emerge weak and sparse. Reducing mulch depth to an inch or two around aster crowns and pulling mulch back from the base of stems discourages vole activity.
On the positive side, asters are highly attractive to pollinators, which is one of their strongest selling points for wildlife-friendly gardens. Late-blooming asters provide critical nectar for migrating butterflies and native bees preparing for winter. Balancing the desire to protect asters from browsers while keeping them accessible to pollinators is a practical design consideration. Scent-based deer repellents do not seem to deter pollinators significantly, which makes them a more compatible option than physical barriers that can impede insect access to flowers.