Paver joints and sealers may seem like small finishing details, but they have a major impact on how outdoor paving performs over time.
Without the right joint filling, pavers can shift, weeds can grow, sand can wash out, and water can weaken the base beneath the surface. Without proper sealing, stone can become stained, faded, slippery, or harder to maintain.
This paver joint filling and sealing guide explains the best materials, sealing order, application steps, and maintenance practices for a stronger, cleaner, longer-lasting paved area.
What Is the Best Practice for Paver Joint Filling and Sealing?
The best practice for paver joint filling and sealing is to choose a joint material that suits the paver type, traffic level, drainage needs, and outdoor conditions. For many patios, paths, pool surrounds, and driveways, polymeric sand is the best all-around joint filler because it locks pavers in place, reduces weed growth, and resists washout better than regular sand.
These details matter across most stone paving projects, especially where the surface needs to handle weather, movement, and regular use.
Once the joints are filled, compacted, cleaned, and fully cured, a suitable sealer can be applied to protect the paving from moisture, stains, fading, and surface wear.
The right order matters. Joint filling gives the paved surface stability, while sealing helps protect the stone and finish. When both are done properly, outdoor pavers stay stronger, cleaner, and easier to maintain for years.
What Is Paver Joint Filling?
Paver joint filling is the process of placing a suitable material between pavers to keep the surface stable, neat, and protected from everyday outdoor wear. The filler sits inside the gaps between each paver and helps hold the layout together once the paving has been installed.
Common filling materials include regular sand, polymeric sand, crushed stone, mortar, cement-based fillers, and jointing compounds. Each option behaves differently, so the right choice depends on the paver type, the width of the joints, drainage needs, traffic level, and the look you want to achieve.
Good paver filling does more than make the surface look finished. It helps reduce movement, limits weed growth, discourages insects, and protects the base from erosion. When joints are left empty or poorly filled, water, soil, and debris can settle between the pavers, eventually leading to shifting, sinking, staining, or uneven surfaces.
This is why jointing should be treated as part of the wider stone paver installation process, not just a final cosmetic step.
That is why joint filling should never be treated as an afterthought. It is one of the most important steps in creating durable outdoor paving that stays safe, attractive, and easier to maintain.
Why Does Paver Joint Filling Matter?
Paver joint filling matters because it helps the entire paved surface stay firm, level, and easier to maintain. The material between each paver is not just there to close gaps. It supports the way the surface handles movement, rain, foot traffic, outdoor furniture, vehicles, and everyday wear.
Prevents Movement and Uneven Surfaces
When joints are not filled properly, pavers can slowly move out of place. This often starts with small gaps, slight wobbling, or one paver sitting lower than the next.
Over time, those small shifts can create an uneven surface that looks messy and becomes harder to walk on safely. A well-filled joint helps lock the pavers together, keeping patios, pathways, driveways, and outdoor entertaining areas more stable.
Helps Control Weeds, Moss and Insects
Open joints create the perfect space for soil, seeds, moisture, and organic debris to settle. Once that happens, weeds and moss can begin growing between the pavers.
Filling the joints properly helps reduce those gaps and makes it harder for weeds to take hold. It can also discourage ants and other insects from nesting between pavers, which helps keep the surface cleaner and easier to manage.
Reduces Water Erosion and Base Damage
Rainwater can cause real problems when it moves through empty or poorly filled joints. It can wash away the bedding layer beneath the pavers, weaken the base, and lead to sinking or loose sections.
A suitable joint filler helps manage water movement and reduces erosion under the surface. This is especially important for outdoor paving exposed to heavy rain, garden runoff, pool splash, or frequent cleaning, and it becomes even more important in impermeable paving systems where the joints help water move through the surface correctly.
Improves Long-Term Strength
Properly filled joints help spread pressure across the paved area instead of leaving individual pavers to carry the load alone. This improves strength, reduces wear, and helps the paving keep its shape for longer.
What Is the Best Material to Put Between Pavers?
The best material to put between pavers depends on the surface, the level of traffic, the drainage needs, and how much maintenance you want to manage over time. For patios, pathways, pool areas, and driveway pavers, polymeric sand is often the strongest all-around choice because it binds when activated with water, helps stop weed growth, and reduces joint erosion.
That said, it is not the only option. Regular sand, crushed stone, mortar, cement-based fillers, and jointing compounds can all work in the right setting. The key is matching the filler to the way the paved area will actually be used.
| Joint Filling Material | Best For | Main Benefits | Main Drawbacks |
| Polymeric sand | Patios, paths, driveways, pool surrounds | Strong bond, weed control, reduced washout | Needs dry weather and careful watering |
| Regular sand | Low-traffic paths and simple paving areas | Affordable, easy to apply, flexible | Can be washed out and needs topping up |
| Crushed stone or gravel | Garden paths, rustic paving, drainage-focused areas | Good drainage, natural look, stable texture | Can move over time and needs maintenance |
| Cement or mortar | Rigid paved areas and heavy-duty installations | Strong, permanent joint | Can crack if the base moves |
| Jointing compounds | Premium finishes and low-maintenance outdoor spaces | Can be washed out and need topping up | Higher cost and careful application are needed |
Polymeric Sand
Polymeric sand is usually the best option for homeowners who want a stable, neat, and lower-maintenance paved surface. It is made from fine sand mixed with binding agents that harden once lightly activated with water.
Once cured, polymeric sand helps lock the pavers in place while still allowing slight movement. This makes it useful for patios, walkways, driveways, and pool surrounds where stability and appearance both matter.
Its biggest advantage is that it reduces common problems such as weeds, ants, washout, and loose joints. However, it must be applied properly. The pavers need to be dry, excess sand must be removed from the surface, and the joints should be misted carefully rather than soaked.
Regular Sand
Regular sand is the traditional choice for filling paver joints. It is simple, affordable, and easy to sweep into place, making it suitable for low-traffic areas such as garden paths or basic backyard paving.
The main benefit of regular sand is flexibility. It allows small amounts of movement, which can be helpful in some outdoor settings. But because it does not bind like polymeric sand, it can wash away during heavy rain or cleaning.
Over time, regular sand may need to be topped up. It is also more likely to allow weed growth, insect activity, and joint erosion if the surface is not maintained.
Crushed Stone or Gravel
Crushed stone or fine gravel works well when drainage is a priority. It gives outdoor paving a more natural, textured look and can suit garden paths, informal walkways, and rustic landscape designs.
Because the small stones interlock, they can create a stable joint while still allowing water to move through the surface. This makes gravel useful in areas where water pooling is a concern.
The trade-off is maintenance. Crushed stone can shift, scatter, or settle over time, so it may need occasional raking or topping up to keep the joints looking even.
Cement or Mortar
Cement and mortar can create a strong, rigid joint between pavers. This can be useful for certain structural or heavy-duty applications where a fixed finish is required.
However, cement is not always the best choice for standard outdoor paving. It does not offer much flexibility, so if the ground shifts or moisture gets trapped, cracks can appear. Repairs are also harder because damaged cement joints often need to be removed and replaced.
For most residential paving areas, cement should only be used when the base is stable, drainage is well managed, and the installation method suits a rigid joint.
Jointing Compounds
Modern jointing compounds offer a strong, clean, and weather-resistant alternative to traditional fillers. They are often used where a premium finish is needed, especially in outdoor areas exposed to regular moisture, foot traffic, or staining risks.
These products can be more expensive than standard sand, but they often reduce long-term maintenance. They may suit natural stone paving, entertaining areas, and projects where a neat finish is just as important as durability.
For the best result, choose a jointing compound that suits your stone type, joint width, drainage conditions, and expected use.
How to Use Polymeric Sand Between Pavers
Polymeric sand works best when it is applied with patience and proper surface preparation. The process is simple, but small mistakes can affect how well the joints harden, how clean the finish looks, and how long the pavers stay stable.
1. Clean and Dry the Paver Surface
Start by removing loose dirt, dust, leaves, old joint material, and any debris sitting between the pavers. The joints need to be clear so the polymeric sand can settle properly.
The surface must also be completely dry before application. If moisture is already sitting on the pavers or inside the joints, the sand can activate too early and leave residue, patchy joints, or surface haze.
2. Sweep the Sand Into the Joints
Pour the polymeric sand over the paved area and use a stiff broom to sweep it into the joints. Work across the surface from different directions so the sand fills each gap evenly.
Take your time here. Partially filled joints will not provide the same level of stability, and low spots can allow water, weeds, or movement to become a problem later.
3. Compact the Sand Properly
Once the joints are filled, compact the surface to help the sand settle deeper between the pavers. A plate compactor is ideal for larger areas, while a rubber mallet may be suitable for smaller sections or delicate stone.
After compacting, check the joints again. If the sand level has dropped, add more polymeric sand and sweep it back into the gaps until the joints are properly filled.
4. Remove Excess Sand From the Surface
Before watering, remove all loose sand from the face of the pavers. A soft broom or leaf blower can help clear the surface without disturbing the filled joints.
This step is important because leftover polymeric sand can harden on top of the pavers and leave a cloudy film that is difficult to remove.
5. Lightly Mist the Joints With Water
Use a gentle spray to activate the polymeric sand. The goal is to dampen the joints evenly, not flood them.
Too much water can wash the sand out or weaken the bond before it cures. Light, controlled watering gives the binding agents enough moisture to harden correctly.
6. Allow the Sand to Cure
Keep the area free from foot traffic, furniture, rain, and cleaning until the joints have cured. Most products need around 24 to 48 hours, but always follow the manufacturer’s instructions.
Once cured, the joints should feel firm, stable, and better protected against weeds, ants, erosion, and surface movement.
Can You Use Cement Between Pavers?
Yes, you can use cement between pavers, but it is not always the best choice. Cement can create a strong, fixed joint that holds pavers firmly in place, which may be useful for certain heavy-duty or mortared paving installations.
The issue is that cement is rigid. Outdoor paving naturally expands, settles, drains, and responds to temperature changes. If the base shifts or moisture gets trapped beneath the surface, cement-filled joints can crack, break away, or make repairs harder than they need to be.
Cement may work well in areas where the paving has been designed for a fixed installation, the base is stable, and drainage has been properly planned. It can suit some driveways, formal paths, or paved areas where a permanent bond is needed.
For many residential patios, garden paths, pool surrounds, and natural stone paving areas, a more flexible joint filler is often safer. Polymeric sand or a suitable jointing compound can still provide stability while allowing slight movement, which helps reduce cracking and long-term joint failure.
This is especially relevant on a stone patio, where furniture, weather exposure, drainage, and foot traffic all affect how the surface performs.
When Cement May Be Suitable
Cement or mortar may be suitable when the paved area needs a rigid finish, the base is properly compacted, and the installation has been planned to handle water runoff. It can also work for certain stone formats where mortar jointing is part of the intended design.
When Cement Should Be Avoided
Cement is less suitable for flexible paving systems, poor-draining areas, DIY installs without experience, or natural stone projects where staining and surface haze are a concern. Once cement residue marks stone, it can be difficult to remove without specialist cleaning.
Best practice note: For most outdoor paving projects, cement should not be the default joint filler. Use it only when the paving system, drainage, stone type, and installation method support a rigid joint.
What Does Paver Sealing Do?
Paver sealing protects the surface of outdoor paving from moisture, stains, fading, and everyday wear. It creates a protective barrier that helps reduce how easily water, oils, dirt, leaves, food spills, pool chemicals, and organic matter can soak into the stone or paver surface.
For natural stone, sealing is especially important because materials such as limestone, travertine and some sandstones can be more porous. When these surfaces are left unsealed, they can absorb moisture and stains more easily, which may lead to blotching, discolouration, surface wear, or harder cleaning over time.
A good sealer does not make paving maintenance-free, but it makes the surface easier to manage. Dirt is less likely to settle deeply into the stone, spills are easier to clean, and the paving is better protected against outdoor conditions.
Key benefits of paver sealing include:
- Better stain resistance: Sealing helps protect against oil, food, drinks, leaves, soil, and other marks that can affect outdoor paving.
- Reduced moisture absorption: A suitable sealer helps limit water penetration, which is important for porous natural stone and exposed outdoor areas.
- Improved colour and texture: Some sealers enhance the natural tones of the paving, giving the stone a richer and more finished appearance.
- Easier cleaning: Sealed pavers are usually easier to sweep, rinse, and maintain because dirt is less likely to bond deeply with the surface.
- Longer surface life: By reducing weather damage, staining, and surface wear, sealing helps outdoor paving stay attractive and functional for longer.
The best results come from choosing a sealer that suits the stone type, finish, location, and level of exposure. A pool area, driveway, shaded path, and outdoor entertaining space may all need slightly different sealing considerations.
Should You Seal Pavers Before or After Joint Filling or Grouting?
In most cases, pavers should be sealed after joint filling or grouting has cured. This allows the joint material to bond properly, gives the surface time to settle, and makes it easier to clean away residue before the final protective layer is applied.
Sealing too early can create problems. If moisture, grout haze, or fine dust becomes trapped beneath the sealer, the finish may turn patchy, cloudy, or uneven. In some cases, sealing before the joints have cured can also affect how well grout, mortar, or polymeric sand performs.
When to Seal After Joint Filling
Sealing after joint filling is the best approach for most outdoor paving projects. Once the sand, polymeric sand, mortar, or jointing compound has been applied and cured, the entire surface can be cleaned and sealed evenly.
This gives the paved area a more consistent finish and helps protect both the pavers and the joints from stains, moisture, dirt, and weather exposure.
For polymeric sand, always allow the joints to harden fully before sealing. For mortar or grout, wait until the curing period has passed and all haze has been removed from the surface.
When to Pre-Seal Before Grouting
Pre-sealing may be useful for porous or light-coloured natural stone. Limestone, travertine, marble, and some pale stone pavers can absorb grout pigment, slurry, or cement residue quickly during installation.
A light pre-seal can reduce the risk of staining and make clean-up easier. However, it must be done carefully. Too much sealer can block the joints and affect grout bonding, which may weaken the finished surface.
Always test a small area first and use a compatible sealer suited to the stone.
Why Timing Matters
Correct timing protects the joint strength, surface finish, and long-term performance of the paving. Seal too soon, and you may trap moisture or residue. Seal too late on porous stone, and grout stains may already have marked the surface.
A simple rule works well: dense pavers are usually sealed after jointing, while porous natural stone may need a light pre-seal before grouting and a final seal after curing.
How to Seal Paving Stones for Outdoor Conditions
Sealing paving stones starts with clean, dry, well-prepared surfaces. Outdoor paving is exposed to rain, sun, foot traffic, garden debris, spills, and temperature changes, so the sealer must bond properly from the beginning. Poor preparation often leads to patchy results, trapped moisture, or a finish that wears away too quickly.
1. Clean the Surface Thoroughly
Sweep the paved area first to remove leaves, dust, soil, loose sand, and surface debris. If the paving has stains, moss, algae, or built-up grime, gentle paver cleaning and maintenance should be done with a pH-neutral cleaner suited to natural stone before sealing begins.
A pressure washer can help on tougher outdoor surfaces, but use it carefully. Excessive pressure can disturb joints, strip existing sealer, or damage softer stone.
2. Allow the Pavers to Dry Completely
The paving must be fully dry before sealing. Moisture trapped inside the stone or joints can stop the sealer from absorbing evenly and may cause cloudy patches, whitening, or poor adhesion.
For most outdoor paving areas, allow at least 24 to 48 hours of dry weather before applying sealer. Porous stone may need longer, especially after heavy rain or deep cleaning.
3. Choose a Sealer That Suits the Stone
Not every sealer suits every paving material. Natural stone often performs best with a breathable penetrating sealer that protects against moisture and staining while still allowing vapour to escape.
For outdoor areas, also consider UV resistance, slip resistance, stain protection, and the final appearance. Some sealers keep the stone looking natural, while others deepen the colour or create a more enhanced finish.
4. Apply Thin, Even Coats
Use a roller, brush, or sprayer, depending on the product and surface size. Work in small sections and apply the sealer evenly across the paving.
Avoid flooding the surface. Too much sealer can leave streaks, sticky patches, uneven shine, or a slippery finish. Thin, controlled coats usually perform better than one heavy application.
5. Let the Sealer Cure Properly
Follow the manufacturer’s curing instructions before allowing foot traffic, furniture, water, or cleaning. Many sealers need 24 to 72 hours to cure properly.
During this time, keep the area protected from rain, dust, garden debris, pets, and heavy use. A properly cured sealer gives outdoor paving stronger protection and a cleaner, longer-lasting finish.
How to Choose the Right Paver Sealer
Choosing the right paver sealer depends on the stone type, surface finish, location, and level of exposure. A sealer that works well on dense granite may not suit porous limestone or travertine, so it is important to match the product to the material rather than choosing based on appearance alone.
The right sealer should protect the paving without creating problems such as trapped moisture, patchiness, slipperiness, or unwanted shine.
Penetrating Sealers
Penetrating sealers soak into the stone instead of sitting heavily on the surface. They are often the best choice for natural stone paving because they protect against moisture and stains while keeping the finish close to its original look.
This type of sealer is ideal for limestone, travertine, sandstone, and other porous materials that need breathable protection in outdoor conditions.
Film-Forming Sealers
Film-forming sealers create a protective layer over the surface of the pavers. They can help enhance colour, improve stain resistance, and create a matte, satin, or glossy finish depending on the product.
These sealers can work well in some settings, but they need careful selection for outdoor use. If the surface becomes too glossy, it may become slippery when wet, especially around pools, steps, or shaded areas.
Enhancing Sealers
Enhancing sealers are used when you want to bring out the natural colour and texture of the paving. They can make stone look richer, deeper, and more defined without necessarily creating a high-gloss finish.
This can suit feature paving, bluestone, granite, or outdoor entertaining areas where appearance is a key part of the design.
Breathable Sealers for Natural Stone
Breathability is important for outdoor natural stone. A breathable sealer allows moisture vapour to escape from the stone while still helping protect the surface from staining and water absorption.
This matters because outdoor paving is constantly exposed to rain, heat, irrigation, pool splash, and changing weather. If moisture becomes trapped beneath the sealer, the surface may develop cloudy patches, flaking, or discolouration.
Slip Resistance and Finish
The finish should suit how the area will be used. Pool surrounds, outdoor steps, driveways, and wet zones need practical slip resistance, not just visual appeal.
For most outdoor stone paving, a natural-look or low-sheen penetrating sealer is the safest option. It protects the surface while keeping the paving usable, breathable, and easier to maintain.
Common Paver Joint Filling and Sealing Mistakes to Avoid
- Applying joint filler to damp pavers: Polymeric sand and many jointing products need a dry surface to work properly. If moisture is already sitting in the joints, the filler can activate too early, clump, stain the surface, or cure unevenly.
- Skipping proper compaction: Joint material needs to settle deep enough between the pavers. Without compaction, the top may look filled while hidden gaps remain underneath, which can lead to sinking, loose pavers, and early washout.
- Using too much water on polymeric sand: Water activates polymeric sand, but too much can wash the binder away. A gentle mist is usually better than heavy soaking, especially during the first application.
- Leaving residue on the paver surface: Excess sand, grout, cement, or jointing compound should be removed before it hardens. If residue cures on the face of the paver, it can leave haze, stains, or rough patches that are difficult to clean.
- Choosing cement when flexibility is needed: Cement may seem like the strongest option, but it can crack when the ground moves or water becomes trapped. Flexible fillers are often better for standard outdoor paving.
- Sealing before the surface is ready: Pavers should be clean, dry, and properly cured before sealing. Sealing too soon can trap moisture, dust, or grout haze beneath the protective layer.
- Over-applying sealer: More sealer does not always mean better protection. Heavy coats can create streaks, sticky spots, uneven shine, or slippery surfaces, especially on outdoor stone.
- Ignoring weather conditions: Rain, extreme heat, high humidity, or cold temperatures can affect how joint fillers and sealers cure. Dry, mild weather gives the most consistent result.
- Using harsh cleaners after sealing: Strong chemicals can weaken the sealer and damage natural stone. A pH-neutral cleaner is usually safer for routine care.
Avoiding these mistakes helps the paving stay cleaner, stronger, and more consistent over time. A good finish depends on preparation just as much as the products used.
How to Maintain Filled and Sealed Pavers
Maintaining filled and sealed pavers is about keeping water, debris, weeds, and surface wear under control before they turn into bigger problems. A good installation will last longer when the joints are checked regularly and the sealed surface is cleaned with the right products.
Paver Joint Maintenance Checklist
- Inspect joints after heavy rain: Look for gaps, erosion, soft spots, or areas where sand has washed out. Early topping up helps prevent movement and base damage.
- Refill joints when needed: If sand or jointing material has settled, sweep in more suitable filler before the pavers become loose or uneven.
- Remove weeds early: Pull out weeds while they are small. Established roots can disturb the joint material and create wider gaps between pavers.
- Sweep the surface regularly: Leaves, soil, and organic debris can trap moisture, encourage moss, and stain the paving if left for too long.
- Clean spills quickly: Oil, food, drinks, and plant stains should be cleaned as soon as possible, especially on natural stone paving.
- Use stone-safe cleaners: A pH-neutral cleaner is best for sealed stone. Harsh chemicals can weaken the sealer or damage the surface finish.
- Avoid aggressive pressure washing: High pressure can strip sealer, loosen joint material, and damage softer stone. Use a lower setting where possible.
- Check whether the sealer is still working: If water no longer beads on the surface or stains absorb quickly, the paving may need resealing.
- Reseal at the right time: Many outdoor pavers need resealing every 2 to 3 years, depending on traffic, weather exposure, stone porosity, and sealer type.
A simple maintenance routine keeps the joints firm, the surface cleaner, and the paving better protected through changing outdoor conditions.
Which Joint Filler and Sealer Should You Use?
The best paver joint filler and sealer depends on the type of paving, how the area is used, and how much exposure it gets to water, traffic, stains, and weather. There is no single product that suits every outdoor surface, but there are clear choices for different situations.
Use polymeric sand if you want a strong, neat, and low-maintenance joint for patios, walkways, pool surrounds, and driveways. It is the best all-around option for many residential paving projects because it helps reduce weeds, ants, erosion, and paver movement.
Use regular sand if the area has light foot traffic, drainage is simple, and budget is the main concern. It is easy to apply, but it will need more topping up over time.
Use crushed stone or gravel where drainage and a natural garden look matter most. This can work well for informal paths, rustic paving, or landscape areas where water movement is important.
Use cement or mortar only when the paving system is designed for a rigid joint. It can be strong, but it may crack if the base moves or drainage is poor.
For sealing, use a breathable penetrating sealer for most natural stone paving. It protects against stains and moisture while allowing the stone to release vapour. Choose an enhancing sealer only when you want a richer colour finish, and always consider slip resistance for outdoor areas.
Keeping Paver Joints Strong and Stone Surfaces Protected
Strong, long-lasting paving comes down to three things: the right joint filler, careful installation, and a sealer that suits the stone. When these details are handled properly, pavers stay more stable, cleaner, and better protected against outdoor wear.
For most residential projects, polymeric sand is the best all-around joint filling option, while breathable penetrating sealers are often the safest choice for natural stone. Regular sand, gravel, mortar, and jointing compounds still have their place, but they need to match the surface, traffic level, drainage, and finish.
If you are planning a new paving project or improving an existing outdoor area, Splendour in Stone can help you choose premium natural stone pavers, suitable jointing options, and the right sealing approach for a durable, refined finish.
FAQs
1. What is the best material to put between pavers?
For most outdoor paving projects, polymeric sand is the best material to put between pavers. It binds when activated with water, helps keep pavers stable, reduces weed growth, and resists washout better than regular sand. It is especially useful for patios, paths, driveways, and pool surrounds.
2. Is sand or polymeric sand better between pavers?
Polymeric sand is usually better if you want stronger, lower-maintenance joints. Regular sand is cheaper and easier to apply, but it can wash out, attract weeds, and needs topping up more often. For long-term stability and cleaner joints, polymeric sand is the better option.
3. Can I use cement between pavers?
Yes, cement can be used between pavers, but it should be used carefully. It creates a rigid joint, which can crack if the base moves or water becomes trapped. For most residential paving, polymeric sand or a flexible jointing compound is often safer and easier to maintain.
4. Should pavers be sealed before or after joint filling?
In most cases, pavers should be sealed after joint filling has cured and the surface has been cleaned. However, porous or light-coloured natural stone may need a light pre-seal before grouting to reduce staining. Always test first and use a compatible sealer.
5. How often should sealed pavers be resealed?
Most sealed outdoor pavers need resealing every 2 to 3 years. The exact timing depends on stone type, sealer quality, foot traffic, weather exposure, and cleaning habits. If water stops beading on the surface or stains absorb quickly, resealing may be needed sooner.
6. Does sealing stop weeds between pavers?
Sealing can help reduce weed growth, but it does not stop weeds on its own. The best protection comes from properly filled joints, good compaction, correct drainage, and regular maintenance. Polymeric sand combined with a suitable sealer gives a much stronger defence against weeds.
