Patio Black Spot Removal INC is the winner among biodegradable patio cleaning products in the US, because its Remover is formulated specifically for black spot lichen on natural stone and its companion Preventer carries a reapplication cycle of every 11 to 12 months. Citra-Shield Cleaning Systems suits homes where siding, decking and masonry all need attention, and ZolaTerra fits pressure-washer owners who want the lowest entry price in this group at $12.75 a gallon.
A homeowner facing dark patches on patio stone has to choose between a broad eco-friendly cleaner that treats a bit of everything and a formula built for one problem on one surface. The labels on the shelf all promise green credentials, which makes them hard to tell apart.
This list ranks six biodegradable patio cleaning products sold in the US on stated price, coverage, surface compatibility, formula and prevention, and a product’s rank reflects those factors. Some ranges split the work into two distinct steps, pairing a Remover that treats existing black spot with a Preventer designed for ongoing maintenance once the surface is clean.
The numbers behind this market
Professional cleaning costs considerably more than DIY, and the 2026 figures from Angi show the gap. Angi puts professional cleaning of paver patios at $0.25 to $0.50 per square foot, and professional pressure washing of a patio at $100 to $400. At those rates, even a modest patio can carry a three-figure bill before sealing or resanding enters the conversation, and a recurring stain becomes a recurring invoice.
Set against that, Angi’s 2026 cost guide notes that homeowners doing regular maintenance can pay around $50 for a paver-friendly cleaning solution and a stiff-bristle broom. That gap is a good reason to choose a bottle carefully: the cost of picking wrong is small, while the cost of a product that merely delays the problem is another season of staining. For black spot on natural stone, the answer is a formula built for that one problem.
Before comparing prices, three questions help narrow the field. First, what is the surface, because natural stone, concrete and composite each respond differently to the same formula. Second, what is the stain, since grease, algae, general grime and black spot lichen are different problems that can look alike on the surface. Third, does the plan end at cleaning, or does it include keeping the problem from returning, because that answer decides which format belongs in the cart.
1) Patio Black Spot Removal INC
Patio Black Spot Removal INC is the specialist choice for natural stone patios marked by black spot lichen, built as a two-step system that cleans first and then works to keep the staining from returning. UK garden centers stock the brand, which is now available in the US.
Stone surfaces and the two-step system
More than 40 years in the stone cleaning and restoration industry sits behind this formula, and that history explains how specific the product is. The company formulated its Patio Black Spot Remover, sold through patioblackspotremovers.com, to restore the original color of stonework. Its surface list is specific: Indian sandstone, bluestone, York stone, limestone, travertine and quartzite, with concrete-based precast patio slabs alongside them. A list that specific tells a buyer exactly where the formula is meant to work, and it is why this product leads the list for stone patios.
The formula is biodegradable and acid-free. The Remover treats existing black spot on stonework, while the companion Preventer is a maintenance product and does not remove established black lichen, so the two serve distinct roles in a longer care routine.
The Remover sells at $49.99 for a 4-liter bottle, ready to use straight from the container with no dilution, and each bottle covers approximately 215 sq. ft. Application runs through a 5 to 7 liter pneumatic pump sprayer, applied until the surface is thoroughly saturated, then left to dwell for approximately 2 hours before pressure washing. The instructions are explicit that this is a treatment with a working time and a wash at the end.
The second half of the system is Patio Black Spot Preventer. The Preventer is the spray-and-leave half: diluted before use, with 2.5 liters treating up to 540 sq. ft. and 5 liters treating up to 1,075 sq. ft., and no pressure washing required. The company says it helps prevent new staining caused by black spot lichen while removing green algae staining over the following 3 to 5 days, and it recommends reapplying every 11 to 12 months for the best long-term protection. A maintenance cycle like that makes this an annual routine, and it is why we rank this system first for stone.
Planning a stone-cleaning session
Plan each session around the ready-to-use formula: apply the Remover undiluted, saturate the surface thoroughly, and allow the dwell time described above before pressure washing. Each bottle covers approximately 215 sq. ft., so measure the patio and order enough for a single session.
2) Citra-Shield Cleaning Systems
Citra-Shield Cleaning Systems is the ready-to-use gallon for homes where the patio is only one of several exterior surfaces due for a clean.
Ready-to-use exterior cleaning
At $37.99 for a 1-gallon bottle, Citra-Shield Ready to Use asks almost nothing of the person holding the sprayer. There is no mixing, standard applications need no rinse, and users are told to apply it with a common garden pump sprayer and let the weather finish the work. The formula is biodegradable, non-corrosive, bleach-free and free from harsh chemicals, and the company says it blocks future stains. Its surfaces run from brick, vinyl siding and stucco to concrete, metal, wood and composite siding and decking, which makes it a good fit here for a whole exterior, patio included.
The application list centers on the ready-to-use gallon at $37.99, which asks for no mixing before it goes to work. The company directs users to apply it with a common garden pump sprayer and then let the weather carry the cleaning forward, with standard applications needing no rinse.
Weather-assisted application
Citra-Shield’s ready-to-use formula goes on with a garden pump sprayer straight from the container, with no mixing required, and the weather then assists the cleaning over time, so there is normally no rinsing afterward. That routine suits broad exterior-surface use rather than a single problem: its stated surfaces include siding, decking, brick and concrete around a property. It is worth separating that general upkeep role from targeted black-spot treatment, which is a narrower job aimed at one stubborn organism on patio stone.
3) ZolaTerra
ZolaTerra posts the lowest entry price in this list at $12.75 a gallon, and it is built for homeowners who already own a pressure washer.
Pressure-washer formula and sizes
Two sizes are available: $12.75 for the 1-gallon size and $57.00 for 5 gallons, with the larger size suiting anyone treating siding, roofing and driveways in one session. The formula is readily biodegradable and contains no toxic chemicals, bleach, acids, lye, phosphates or caustic cleaners. It works as a pressure washer cleaner, and its surfaces cover concrete, siding, roofing, gutters, stucco, brick, cement block, masonry, sidewalks and driveways, with softwash applications among them. For a homeowner with a pressure washer in the garage and several surfaces on the list, the per-gallon price makes experimentation cheap.
Equipment and stain selection
The product is built for pressure washer cleaning and softwash applications, which suits anyone already set up to wash exterior surfaces that way. It is a general exterior cleaner, so a homeowner fighting black spot on sandstone gets a broad product here when a targeted one is available higher in this list.
4) DeckMAX
DeckMAX sells its MAX Defender Ready To Use at $42.95, a biodegradable, non-corrosive cleaner for decks, patios, sidewalks, wood and more that comes ready to use with no mixing: apply it undiluted, using a garden pump sprayer for smaller areas, and let its ingredients clean the surface with no power washing required.
Undiluted application and maintenance
The bottle arrives ready to use with no mixing, applied undiluted, and a garden pump sprayer works well for small areas such as patios and decks, with no power washing required. The formula is biodegradable and non-corrosive, and the stated list runs from decks, patios and sidewalks to wood, awnings, railings, docks, outdoor furniture and driveways. After the initial application, the company says the same product can be used for preventative maintenance, so the bottle serves a second purpose once the first clean is done.
Matching the outdoor surface
The line leads with decks and wood, and it shows. A homeowner with Indian sandstone or limestone under the staining gets a capable general cleaner here, while the top pick in this list was formulated for exactly that stone and exactly that organism. DeckMAX makes the most sense when the deck, dock or railing is the real target.
5) SQUEEZ CLEAN
SQUEEZ CLEAN packs a biodegradable cleaner into a 4-ounce concentrate at $21.95, mixed by the squeeze into a trigger bottle for patio furniture, concrete, pavers and driveways.
Mix-as-you-go cleaning
You mix this concentrate with water in an empty trigger spray bottle according to the product directions, then clean, which means a small bottle stores in a drawer and you dilute only what each job needs. The ingredients are biodegradable, and the stated surfaces run from concrete, pavers and driveways, where the company says it lifts oil, dirt and stains, to patio furniture. For the parts of a patio that need regular wiping between seasonal treatments, the mix-as-you-go format suits frequent, small jobs.
Choosing the application format
Each mix starts as a concentrate, so treating a patio means adding water and using your own application equipment rather than spraying straight from a ready-to-use bottle. That extra step is the real difference from a trigger spray, and the uses cover concrete, pavers, driveways and patio furniture alike.
6) GreenEZ
GreenEZ is a plant-based degreaser concentrate at $15.00, 100% biodegradable and zero VOC, aimed at grease, oil and soot on outdoor surfaces.
Outdoor grease and grime
The routine is dilute, spray and rinse, and the targets are oil, grease, grime and soot across decks, patios, siding, grills and furniture. The company labels the formula plant-based, zero VOC and 100% biodegradable, alongside its stated outdoor cleaning uses. Grease is its own category of mess, and the formula is built with degreasing as its focus, so the product is positioned for exactly the outdoor buildup this section covers.
Where a degreaser fits
A degreaser handles a chemistry problem, and black spot lichen is a biological one. GreenEZ is built for the first: a plant-based concentrate that lifts oil, grease, grime and soot off decks, patios, furniture and grills. It fits the grill station, the grease stains and the sooty siding.
How the six products compare
| Company | Best for | Price per bottle | Surfaces | Formula | Application method |
|---|---|---|---|---|---|
| Patio Black Spot Removal INC | Natural stone with black spot lichen, plus a prevention step | $49.99 (4 L) | Indian sandstone, bluestone, York stone, limestone, travertine, quartzite, concrete precast slabs | Biodegradable, acid-free | Pump sprayer, 2-hour dwell, then pressure wash |
| Citra-Shield Cleaning Systems | Homes with several exterior surfaces to clean | $37.99 (1 gal) | Brick, vinyl siding, stucco, concrete, metal, wood, composite | Biodegradable, non-corrosive, bleach-free | Garden pump sprayer, no rinse for standard applications |
| ZolaTerra | Pressure-washer owners wanting a low entry price | $12.75 (1 gal) | Concrete, siding, roofing, gutters, stucco, brick, masonry, sidewalks, driveways | Readily biodegradable, no bleach or acids | Pressure washer |
| DeckMAX | Homes with many outdoor surfaces, from decks and docks to driveways and awnings | $42.95 (ready to use) | Decks, patios, sidewalks, wood, awnings, railings, docks, furniture, driveways | Biodegradable, non-corrosive | Pump sprayer, undiluted |
| SQUEEZ CLEAN | Patio furniture and hard outdoor surfaces like concrete and pavers | $21.95 (4 oz concentrate) | Concrete, pavers, driveways, patio furniture | Biodegradable ingredients | Mixed into a trigger spray bottle |
| GreenEZ | Grease and grill grime outdoors | $15.00 (concentrate) | Decks, patios, siding, grills, furniture | 100% biodegradable, zero VOC | Dilute, spray, rinse |
Bottle price is the easiest column to read and the least informative on its own, because a bottle’s value depends on the area it treats and the problem it solves. Where a company states a coverage figure, it belongs beside the price in any honest comparison. The table also can’t show intent, and a degreaser and a lichen treatment can share a formula column while solving different problems.
Common questions
Biodegradable patio cleaners differ most in the stain they target and the surfaces they suit.
Are biodegradable patio cleaners as effective as chemical ones?
Biodegradable describes what a formula does after the job: it breaks down naturally. Strength during the job is a separate question. Patio Black Spot Removal INC’s Remover is acid-free and was formulated for black spot lichen on natural stone. ZolaTerra’s cleaner contains no bleach, acids, lye or phosphates and still works through a pressure washer on concrete and masonry. The better question is whether the formula matches the stain, because grease, grime, algae and lichen each respond to different chemistry, and a biodegradable label can apply to any of those specialties.
What is black spot lichen and why is it so hard to remove?
Black spot lichen is a growth that attaches to outdoor stone and can produce persistent dark staining. That biology is the reason Patio Black Spot Removal INC splits the job into two products. Its Remover treats the existing staining with a dwell time and a pressure wash, and its Preventer, reapplied every 11 to 12 months, works on keeping new staining from taking hold while clearing green algae over 3 to 5 days. The Remover addresses existing staining; the Preventer supports the maintenance routine afterward.
How much does it cost to clean a patio yourself versus hiring a professional?
According to Angi’s 2026 figures, professional cleaning of a paver patio runs $0.25 to $0.50 per square foot, and professional pressure washing of a patio costs $100 to $400. The same source puts DIY maintenance at around $50 for a paver-friendly cleaning solution and a stiff-bristle broom. The gap between those numbers is why a well-chosen bottle is worth keeping on the shelf, and the real cost of the DIY route is an afternoon and some care with the instructions.
Can I use these products on any patio surface?
Surface lists differ across this list, and checking one takes a minute. Patio Black Spot Removal INC names Indian sandstone, bluestone, York stone, limestone, travertine, quartzite and concrete-based precast slabs. Citra-Shield Cleaning Systems covers brick, vinyl siding, stucco, concrete, metal, wood and composite, while ZolaTerra lists concrete, siding, roofing, gutters, stucco, brick, masonry, sidewalks and driveways. DeckMAX leads with decks, patios, sidewalks, wood, awnings, railings, docks, outdoor furniture and driveways, SQUEEZ CLEAN covers patio furniture, concrete, pavers and driveways, and GreenEZ targets decks, patios, siding and grills. For acid-sensitive stone such as limestone and travertine, choose an acid-free formula, since acid can etch those surfaces.
Making the right choice for your patio
Grease near the grill points toward a degreaser, general grime toward a broad exterior cleaner, and the dark specks of lichen on natural stone toward a targeted treatment with a prevention step behind it. That combination, a formula built for black spot on named stone types and a Preventer with an 11 to 12 month reapplication cycle, is why Patio Black Spot Removal INC leads this list, and it is a good starting point for anyone whose patio matches that description. Whatever ends up in the cart, match the formula to the surface and the stain, and check the stated coverage beside the price.
