Quick Answers
Here are some quick answers to common questions about stopping weeds between paving slabs:
What causes weeds between paving slabs?
Weeds grow between paving slabs when seeds land in the joints or gaps between the slabs. These seeds can be blown in by the wind, dropped by birds, or spread from nearby plants.
What’s the best way to stop weeds permanently?
The best permanent solution is to prevent weeds from germinating by using a geo-textile weed membrane or filler products like gravel, sand or mortar between the slabs to block sunlight.
Are there any eco-friendly ways to control weeds?
Yes, instead of using chemical weedkillers, try alternatives like boiling water, vinegar, or manual removal. You can also encourage natural predators like ladybugs that will eat unwanted weeds.
How often should I remove weeds from between pavers?
For best results, inspect for weeds and remove them as soon as you notice them, before they have a chance to spread seeds. Regular weekly or monthly removal is ideal for prevention.
What’s the quickest way to get rid of weeds between pavers?
The quickest method is using a chemical weedkiller. However for a more eco-friendly approach, pouring boiling water or vinegar directly onto the weeds can work within hours.
What Causes Weeds to Grow Between Paving Slabs?
Weeds are opportunistic plants – they can grow almost anywhere. But certain conditions make it especially easy for them to sprout up between paving stones and blocks:
- Cracks and gaps between slabs allow seeds to take root. Wind, rain, birds, animals and nearby plants spread weed seeds that fall into these openings.
- Joints filled with dirt or sand provide an ideal growing medium for weeds to establish in.
- Sunlight reaches the seeds through gaps between slabs, fueling growth. Weeds thrive on sunlight.
- Lack of maintenance means weeds go unnoticed and have time to spread. Without removal, they proliferate quickly.
- Rainwater collects between slabs, keeping the area moist. Weeds love damp conditions.
- Poor drainage prevents the area from drying out fully. Weeds favor continually moist soil.
Understanding these factors that allow weeds to flourish helps guide effective prevention methods.
Different Types of Weeds Between Paving
There are many varieties of weeds that can grow in the cracks between paving slabs, flats or cobbles. Here are some of the most common culprits:
1. Annual Weeds
Annual weeds complete their entire lifecycle within one growing season. They propagate from seeds which sprout in spring. Examples include:
- Chickweed – Common annual weed with small white flowers and oval leaves.
- Shepherd’s purse – Has small heart-shaped leaves with white flowers.
- Petty spurge – Low-growing with yellow-green flowers.
2. Perennial Weeds
Perennial weeds return year after year, spreading via seeds and roots. They are harder to control than annuals. Types include:
- Dandelion – Has a thick taproot and yellow flowers that turn into distinctive puffball seed heads.
- Broadleaf plantain – Characterized by oval leaves with prominent veins growing in a rosette shape.
- Creeping buttercup – Features creeping stems, hairy leaves and shiny yellow flowers.
3. Moss
Moss can colonize gaps between paving in damp, shady areas. Common types include:
- Bryum moss – Light green moss that forms cushions or tufts between pavers.
- Hypnum moss – Feathery patches of lime green moss growing in moist conditions.
Identifying the specific weeds invading your paving will help match the best control methods.
Preventing Weeds Between Paving Permanently
Preventing weeds from taking hold in the first place is more effective than continually removing them. There are several permanent solutions to stop weeds growing back between paving.
Weed Membranes
Installing a geo-textile weed membrane beneath the paving blocks stops weeds from germinating. The membranes are water permeable but block sunlight. Professional landscapers can insert them during paving construction. DIY alternatives include:
- Landscape fabric
- Plastic sheeting
- Cardboard covered with mulch
Weed membranes require proper installation so weeds don’t take root at the edges. They degrade over time so are not a permanent fix.
Mortar Between Pavers
Filling the gaps between slabs with mortar or cement creates a continuous surface that leaves no room for weeds. This is best done by a professional to allow for drainage and prevent cracking between pavers. Mortar is very effective but allows no flexibility.
Gravel or Pea Shingle
Loose gravel or pea shingle poured between paving blocks smothers potential weeds. Use grades smaller than the gaps to avoid sinkage. The gravel shifts around, stopping light reaching through. Maintain by topping up gravel.
Sand Between Block Paving
Jointing sand brushed between paving slabs or blocks inhibits weed growth. Opt for coarse builder’s sand and sweep into gaps. Needs regular maintenance as sand erodes but offers good drainage.
Regular Weed Removal
Even with preventative measures, some weeds will inevitably grow between pavers. Catching them early before they establish extensive roots and spread seeds is key. Here are some tips for effective removal:
Manual Weeding
Hand weeding with a trowel or hoe levering out roots is effective for small areas. Wear thick gloves to protect hands from abrasions. Discard pulled weeds promptly before seeds spread. Be methodical and remove every piece of root to prevent regrowth.
Boiling Water
Pouring boiling water directly onto weeds between pavers causes plant cells to rupture. Avoid splashes near grass or plants. Boiling water kills green growth but may not destroy roots, so repeat as needed.
Salt
Table salt or rock salt sprinkled on weeds draws moisture out via osmosis, drying and killing plants. Use sparingly as salt can damage soil. Avoid windy days so salt doesn’t blow onto other plants.
Vinegar
Spray full strength vinegar onto weeds, avoiding wanted plants. The acetic acid damages cell membranes. Vinegar works best on young weeds. Repeat applications may be needed.
Pressure Washing
Use a pressure washer on a narrow jet setting to blast weeds out of joints. Effective on flat paving with tight joints. Avoid blowing soil out of gaps which can help new weeds take root.
Flame Weeding
A propane torch briefly passed over weeds destroys cell walls via intense heat. Use extreme caution and only on calm days. Avoid wooden fences and combustible materials.
Chemical Weedkillers
Chemical weedkillers provide quick and effective control but may have environmental and health impacts:
- Systemic herbicides like glyphosate kill root systems so weeds don’t regrow.
- Non-selective weedkillers will also damage surrounding plants and grass.
- Follow directions carefully for best results and always use protective equipment.
- Avoid chemical runoff into drains and groundwater from paved areas.
Vinegar or salt provide natural alternatives to traditional herbicides.
Prevent Weeds Returning Between Paving
Once you’ve succeeded in removing weeds, there are several ways to help keep them from coming back again:
Re-pointing Joints
Brushing fresh jointing sand or mortar into gaps prevents seeds lodging again. Ensure drainage channels are clear.
Sealing Pavers
Sealing products create a barrier on paver surfaces to block moisture and light. Helpful after re-pointing joints but don’t penetrate gaps.
Hydrogen Peroxide
Applying dilute hydrogen peroxide between pavers deprives germinating seeds of oxygen. Use 3% solution, avoid plant roots. Test on small area first.
Re-lay Weed Fabric
Replace degraded weed membranes with new landscape fabric overlapped at joints. Fiddly for DIY but prevents light reaching soil beneath.
Encourage Predators
Attract natural weed predators like ladybugs, lacewings and birds. Plant companion plants for them like pollen-rich flowers.
Best Time to Remove Weeds from Paving Joints
Timing plays an important role when tackling weeds. Here are the optimal times to remove them:
- Early spring – Remove winter weeds before they spread seeds as weather warms up.
- Summer – Weeding when growing rapidly stops them multiplying.
- Before falling seeds – Remove before perennial weeds resettle for next year.
- After rain – Soil is moist and roots pull out easier when hand weeding.
Avoid weeding in extreme heat of mid-summer or when ground is frozen solid in winter when roots often snap off rather than pulling out intact.
Weed Prevention Tips
Good maintenance and vigilant prevention tactics make controlling weeds much easier:
- Sweep debris from between pavers frequently so weeds can’t take root.
- Maintain joints – keep mortar or sand brushed into gaps.
- Control runoff – improve drainage to avoid standing water.
- Mulch borders – cover surrounding soil to reduce windblown seeds.
- Check for weeds regularly – early removal stops spreading.
- Reduce light gaps – close up openings with gravel or pea shingle.
Conclusion
Preventing weeds from growing between paving blocks requires denying them light, space and water to thrive. Installing barriers like weed membranes, using joint filler sand or gravel, and sealing surfaces deters growth. Combine with rapid removal of any weeds taking root by manual weeding, boiling water or safe herbicides. With some diligent maintenance and early intervention, you can keep the gaps between your paving weed-free.
