That's a common and frustrating issue! Those black marks are usually a combination of dirt, moisture, and plastic residue from the bin's base grinding against your patio surface. Don't worry, here are some natural and effective ways to tackle it.
First, to remove existing marks, try these cleaners:
* Dish Soap & Warm Water: Start with the simplest solution. Scrub with a stiff brush.
* Baking Soda Paste: Make a paste with baking soda and water. Apply, let it sit for 15 minutes, then scrub. It's great for concrete.
* White Vinegar Solution: Mix equal parts vinegar and water. Spray on the stain, let it bubble for a few minutes, then scrub. Rinse well.
* For Tough Stains: A dedicated concrete cleaner or a mild solution of oxygen bleach (following package directions) can be very effective.
To prevent the marks from coming back, consider these fixes:
1. Move the Bin Regularly: Simply shifting its position every few days prevents grime from building up in one spot.
2. Use a Protective Mat: Place a durable mat underneath. Options include a plastic bin mat, a rubber welcome mat, or even an inexpensive patio tile.
3. Clean the Bin's Bottom: Regularly hose off and scrub the bottom of the trash bin itself to remove accumulated dirt.
4. Add Casters/Wheels: If your bin doesn't have them, attaching a set of small, smooth-rolling casters can lift the base and allow for easy movement without dragging.
The key is combining a good clean-up with a simple barrier. A sturdy mat is often the easiest long-term solution. Good luck