Bobbex vs Liquid Fence: which deer repellent works better

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Side by side

Bobbex vs Liquid Fence at a glance

These are the two deer sprays people most often stand in an aisle choosing between, and they are more alike than the marketing suggests. Both are built around putrescent (rotting) egg, both add garlic, and both are sprayed directly on the plant so deer smell it and taste it. The real differences are the extra ingredients in Bobbex, the reapplication schedule, how easy each is to buy, and price.

The best independent head-to-head data we found is the three-year trial summarized in University of Maryland Extension fact sheet FS810-A, which tested both products alongside Plantskydd at sites with heavy deer pressure. Averaged over the trial, plants treated with Bobbex lost 17% of their browse-height foliage, Liquid Fence 20%, and Plantskydd 26%, against 49% on untreated plants. That is a real but modest gap between Bobbex and Liquid Fence, and Liquid Fence's numbers moved a lot from year to year.

What is actually in each spray

Liquid Fence lists putrescent whole egg solids and garlic as its active ingredients on its product page and label. That is the whole formula in practical terms: a sulfurous egg smell, backed by a garlic taste.

Bobbex is a longer recipe. Per UMD Extension, it contains fish and/or beef by-products and repels by both odor and taste; the Bobbex label also lists egg and garlic along with other botanical oils. In effect it stacks a second protein smell (fish) on top of the same egg-and-garlic base Liquid Fence uses.

Plantskydd, the third option on this page, is different chemistry: dried blood with a vegetable-oil sticker, per the Plantskydd label. It works on smell alone.

Because Bobbex and Liquid Fence share egg and garlic, rotating between just those two gives deer less novelty than rotating either of them with a blood product. More on that below.

How each one keeps deer off: odor, taste or fear

Deer repellents work in three broad ways. Some smell bad or alarming, some taste bad, and some do both. Per Penn State Extension, contact repellents work by taste and must be applied directly to the plant, while area repellents rely on odor.

Research from the USDA's National Wildlife Research Center, summarized in the Forest Service Forest Nursery Notes, found that products giving off sulfurous odors, the kind putrescent egg and blood produce, generally did better than products that only taste bad. That fits the UMD results: every product in this comparison is sulfur- or blood-based, and all three cut damage well below untreated plants.

• Bobbex: odor plus taste, with egg, fish and garlic.
• Liquid Fence: odor plus taste, with egg and garlic.
• Plantskydd: odor only; the blood smell triggers avoidance.

None of these work like a fence. A hungry deer that has already learned your hostas are food will take a bite, taste it, and sometimes keep eating anyway.

What university trials say about deer repellents

Before you pick a brand, it helps to know what independent testing says about the whole category.

• Maryland: the UMD Extension trial ran three years at sites with very high deer density. Across all products, treated plants averaged 18% browse loss versus 49% untreated, and only 27 of 140 treated plants (19%) lost more than 35% of their foliage, compared with 21 of 28 untreated plants (75%). Repellents clearly work; they do not make plants deer-proof.
• Connecticut: Ward and Williams of the Connecticut Agricultural Experiment Station compared commercial repellents on Japanese yews, a deer favorite; the study is summarized by Conservation Evidence. Bobbex cites Connecticut testing on its label, so read the original summary rather than the marketing version.
• USDA: National Wildlife Research Center comparisons, summarized in the Forest Service Forest Nursery Notes, found sulfurous-odor products such as egg and blood repellents generally outperformed taste-only products.
• Penn State: Penn State Extension stresses application on dry, above-freezing days and direct contact with the plant for taste repellents.

The common thread: the product matters less than starting early, covering new growth and rotating.

How long each lasts, and what rain does

This is the question most people searching "Bobbex vs Liquid Fence" actually want answered, and the honest answer is that label claims and real-world intervals differ.

Liquid Fence: the label directs weekly applications for the first month, then monthly, and calls the product rain-resistant once it has dried. That is the schedule to follow.

Bobbex: the manufacturer markets it as rain-resistant once dry; check the label on your bottle for the current schedule. In the UMD trial, researchers reapplied it every 10 to 14 days during the growing season, a more demanding routine than Liquid Fence's monthly maintenance, and that frequency is part of why its numbers were good.

Plantskydd: the manufacturer claims up to six months on dormant plants in winter, with shorter intervals during active growth. Per UMD Extension, egg- and blood-based products generally last one to three months or more.

Two things shorten every interval regardless of brand. New growth is untreated growth, so anything that leafs out after you spray is unprotected. And deer pressure matters: per UMD, at the highest-pressure sites repellents held damage in check for six to eight weeks in many cases, while 10 to 12 weeks was common at lower-pressure sites.

Reapplication timing that actually works

Whichever you buy, timing matters more than brand:

• Start before damage. Per UMD Extension, apply before the first sign of damage so deer never establish a feeding pattern at the site.
• Spray dry, mild days. Per Penn State Extension, repellents work best applied on dry days when temperatures are above freezing. Give the spray time to dry before rain.
• Follow new growth. In spring, re-treat as new leaves and flower buds emerge; they are what deer want and they carry no repellent.
• Rotate. Per UMD, it is generally recommended that repellents be changed with each application because deer become used to them.

A practical rotation for most yards: Liquid Fence or Bobbex during the growing season, alternating with Plantskydd, and Plantskydd going into winter when you want the longest gap between sprays. That matches the approach in our deer repellent guide.

Concentrate, ready-to-use or hose-end

All three brands come in several formats, and the format often matters more to your week than the formula.

• Ready-to-use trigger bottles are the easiest way to treat a handful of hostas or a single rose bed. They cost more per plant treated but need no mixing.
• Concentrates are mixed in a pump sprayer and make sense once you are treating a hedge, a long border or many shrubs. Per the UMD cost data, Liquid Fence was the cheapest per gallon from concentrate, Bobbex in the middle and Plantskydd the most expensive.
• Hose-end and ready-to-spray bottles, sold by Liquid Fence among others, are fastest for large areas but harder to aim, so more product lands on paths and lawn.
• Granular versions exist for Liquid Fence and Plantskydd and are scattered around plants rather than sprayed on them. They are mainly area treatments and are not a substitute for spraying the foliage deer actually eat.

One practical warning from the UMD researchers: Plantskydd's powder concentrate was difficult to keep in suspension and tended to clog the sprayer. If you choose Plantskydd, the ready-to-use liquid avoids that, or shake the sprayer often.

Smell and safety on edibles, pets and people

All three stink when wet. Liquid Fence smells of rotten egg and garlic, Bobbex adds a fishy note, and Plantskydd smells like blood. Each manufacturer says the odor fades for people once the spray dries, while deer continue to detect it; expect the first day to be the worst.

In practice that means: spray in the evening or when you will not be using the patio for a day, keep it off windows and doors you open, and do not spray plants right next to a seating area the afternoon before guests arrive. If you are sensitive to smell, the ready-to-use bottles make it easier to treat only the plants deer actually target rather than fogging a whole bed.

The label is the law. Read the one on the bottle you buy, because formulations and directions change, and follow it rather than anything you read online, including here.

Per Penn State Extension, most commercial deer repellents are not labeled for use on edible plants, with a few exceptions. Our rule: do not spray the parts of fruit and vegetable plants you will eat unless the label you are holding specifically allows it, and keep pets and children off treated plants until the spray has dried. Plantskydd is OMRI Listed, which matters if you garden organically, but an organic listing is not the same thing as label permission to spray a crop.

On ornamentals, test any repellent on a few leaves first and avoid spraying in hot midday sun, which can scorch tender foliage.

Which to pick for which situation

• Pick Bobbex if you want the stronger independent track record and will commit to frequent sprays through the growing season, for example on hostas, daylilies or roses at a woodland edge.
• Pick Liquid Fence if you want something you can buy today at any hardware store, prefer a simple monthly maintenance schedule, or are treating a large area on a budget.
• Add Plantskydd for winter protection of yews, arborvitae and other evergreens, and as the rotation partner for either egg spray.
• Skip all three as your only defense if deer are flattening plants rated frequently damaged in the Rutgers deer-resistance ratings. In high-pressure yards that is a job for a deer fence, or for replacing the plant with a deer-resistant perennial.

Common mistakes with either spray

• Waiting for damage. Once deer have a feeding habit on a plant, any repellent has a harder job. Spray before buds break in spring and before winter browsing starts.
• Spraying only once in spring. Leaves that open after you spray are untreated. Re-treat through the spring flush on the schedule your label gives.
• Spraying in the rain or right before it. Both products need to dry on the leaf to resist rain.
• Using one product forever. Deer habituate; switch products between applications.
• Treating everything. Spray the plants deer actually browse. Plants rated rarely damaged by Rutgers usually do not need it, which saves product and smell.

How we choose

This comparison is research-based. We did not run our own repellent trial and we are not reporting personal results. Our editor, Thomas Joseph, gardens in zone 7a on Long Island, where deer are a real problem, but the verdicts here come from published sources: the three-year University of Maryland Extension repellent trial, guidance from Penn State Extension and Rutgers NJAES, the Connecticut Agricultural Experiment Station's repellent research, and the current product labels. Where a claim comes only from a manufacturer, we say so. We weight independent trial data above marketing, and we flag where results varied from year to year rather than averaging the nuance away.

Frequently asked

Is Bobbex better than Liquid Fence?

In the University of Maryland three-year trial, Bobbex had a slightly better average (17% browse loss vs 20% for Liquid Fence), and Liquid Fence's results swung more between years. The gap is modest; consistent spraying and rotation matter more than the brand.

How long does Liquid Fence last after spraying?

The label directs weekly applications for the first month and monthly after that, and says it is rain-resistant once dry. Re-treat new growth sooner, because leaves that emerge after spraying are unprotected.

Does Bobbex wash off in the rain?

Bobbex is marketed as rain-resistant once it has dried, so spray when no rain is expected for several hours. Follow the label's reapplication schedule rather than waiting for damage.

Can I use Bobbex and Liquid Fence together?

Alternating them is reasonable, but both rely on egg and garlic, so alternating either one with a blood-based product like Plantskydd gives deer more variety. UMD Extension recommends changing repellents with each application.

Which deer repellent smells the least?

None of the three is pleasant when wet: egg and garlic for Liquid Fence, egg and fish for Bobbex, blood for Plantskydd. All three say the odor fades for people once the spray dries.

Can I spray Liquid Fence or Bobbex on vegetables?

Only if the label on your bottle allows it. Penn State Extension notes most commercial deer repellents are not labeled for edible plants, so keep spray off the parts you plan to eat.

Sources

1. Using Commercial Deer Repellents to Manage Deer Browsing in the Landscape (FS810-A), University of Maryland Extension
2. Orchard Wildlife: Integrated Management of White-Tailed Deer, Penn State Extension
3. Landscape Plants Rated by Deer Resistance, Rutgers NJAES
4. Effectiveness of deer repellents in Connecticut (Ward and Williams, Human–Wildlife Interactions), Conservation Evidence
5. Effectiveness of commercially available deer repellents, USDA Forest Service, Forest Nursery Notes
6. Deer & Rabbit Repellent Ready-To-Use, Liquid Fence
7. Bobbex deer repellent product label, Bobbex (via SiteOne)
8. Frequently Asked Questions about Plantskydd, Plantskydd

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