Weeds such as dandelions tend to get stuck in the joints between patio and sidewalk slabs and are difficult to remove. There is no need for annoying manual weeding or burning weeds if you fill the cracks with stone dust. You can find out why this works so well and how you should go about it in this article.
Why does stone powder help against weeds?
Stone dust is effective against weeds because it lowers the pH of the soil, fills voids in joints, compacts the subsoil and prevents weed roots from spreading while still remaining permeable to water. Simply sprinkle into dry joints and compact.
What is rock dust?
Many hobby gardeners know primary rock flour as a valuable fertilizer that supplies mineral trace elements to the soil and as a natural aid in the fight against vermin and fungi. The starting product for rock powder can be:
- Bas alt
- Lava
- Quartz
- Zeolite
- Diabas
- Granite.
Sometimes clay powder is also ground into primary rock powder.
The ingredients of the product depend on the source rock. However, it always contains high proportions of trace minerals.
Why do rock powders in the joints have a weed-inhibiting effect?
You can use rock dust to permanently remove weeds from the paving stone joints. This works because:
- The minerals lower the pH of the soil, so that weed seeds find suboptimal conditions.
- The fine grain penetrates even the smallest cracks and completely fills cavities.
- The subsoil is so compacted that the weed roots can hardly spread.
Nevertheless, the joints remain permeable to water. The good drainage of rainwater is guaranteed and, as long as the surface is flat, no puddles form.
How is rock dust applied correctly?
Use the joint scraper (€9.00 on Amazon) to remove all weeds and deposited substrate about three centimeters deep. Then proceed as follows:
- Let the joints dry completely before filling them with rock dust.
- Sprinkle the material directly into the cracks.
- Sweep criss-cross over the area to incorporate and compact the rock dust well.
- You can rent surface vibrators in many hardware stores. These make work noticeably easier, especially in large areas such as the courtyard entrance.
Carefully sweep up any excess rock dust. If the joints are completely compacted after a few weeks due to rain and stress, you can fill small depressions with the dry material.
Tip
Primitive rock powder is available in different tones. The color palette ranges from light sandy beige to an almost black anthracite. This allows you to match the filling to the color of your paving stones and create attractive contrasts.
