How to create a self-watering indoor herb garden using repurposed plastic containers
Setup & Materials
By Alex • November 15, 2025 • DIY Guide
Creating a self-watering indoor herb garden is not only a rewarding and sustainable project but also a practical way to enhance your culinary endeavors. Imagine having a constant supply of fresh basil, parsley, mint, and other herbs at your fingertips, all thriving with minimal maintenance. This project is perfect for those who may not have a lot of gardening experience or space but want to indulge in the joys of growing their food.
Why this Project? Indoor herb gardening is increasingly gaining popularity for multiple reasons. First, it allows you to grow fresh herbs without needing a backyard or substantial gardening experience. Herbs can be easily grown in small spaces, such as windowsills, balconies, or kitchen countertops, making them ideal for urban living. Additionally, herbs can elevate your culinary creations, adding flavor and freshness that dried herbs simply cannot match.
Benefits include:
Freshness: Harvest whenever you need, ensuring maximum flavor.
Final Result
Cost-Effective: Save money on purchasing fresh herbs from the grocery store.
Sustainability: Repurposing plastic containers reduces waste and is environmentally friendly.
Aesthetic Appeal: A small herb garden brings life and greenery into your home.
Skill Level: This project is beginner-friendly, requiring minimal skills and tools. With a step-by-step guide, even novices can successfully create their own self-watering system, learning valuable gardening skills without being overwhelmed.
Now, let’s gather the tools and materials you’ll need for this exciting DIY project!
Tools Needed
1. Utility Knife
Why: To cut the plastic containers and create drainage holes.
2. Drill with a Small Bit
Why: An alternative to a utility knife for making drainage holes, providing a cleaner cut and allowing for better ventilation.
3. Measuring Tape or Ruler
Why: To measure the dimensions of your containers and ensure accurate cuts.
4. Marker/Pen
Why: For marking measurement points on your containers before cutting.
5. Scissors
Why: Useful for trimming any additional materials, such as wicks or filter cloths.
6. Potting Soil
Why: Essential for your herb garden; quality soil ensures your plants get the right nutrients.
7. Wicking Material (Polyester Rope or Old T-Shirt)
Why: To transport water from the reservoir to the soil, while keeping the roots hydrated.
8. Container for Water Reservoir
Why: Provides a space where water can be stored and drawn up by the wicking material.
Materials
1. Plastic Containers (2)
Quantity: 2 (These will be the outer and inner pots for the self-watering system.)
2. Wicking Material
Quantity: 1 piece (Typically about 1 to 2 feet long.)
3. Potting Soil
Quantity: 1 bag (Usually around 5 quarts, depending on the size of containers.)
4. Herb Seeds or Seedlings
Quantity: 4-6 packets (Choose your favorite herbs like basil, mint, rosemary, and cilantro.)
5. Plastic Bottle or Cup
Quantity: 1 (Can be used for the water reservoir if not using a dedicated container.)
6. Small Rocks or Gravel
Quantity: About 2-3 cups (Needed for drainage at the bottom of the inner pot.)
7. Filter Cloth or Coffee Filter
Quantity: 1-2 pieces (For covering the holes to prevent soil from falling through.)
8. Water
Quantity: Enough to fill up your reservoir (This will depend on the capacity of your containers.)
9. Fertilizer (Optional)
Quantity: 1 small bag (To provide additional nutrients as your herbs grow.)
10. Labels (Optional)
Quantity: A set (To label each pot with the herb variety.)
Step-by-Step Instructions
### 1. Gather Your Containers
What: Look for suitable plastic containers to use. You’ll want both a larger outer container and a smaller inner container.
How: Aim for containers that are at least 6-10 inches deep. Ideally, the inner pot should fit comfortably inside the outer pot with space for your wicking mechanism.
Tips: Check for food-grade plastic containers to avoid chemicals leaching into your soil. Containers like yogurt cups, 2-liter soda bottles, or larger food containers work well and can typically be found in your recycling bin.
Safety: Ensure that any containers you choose are clean and free from harmful residues. Rinse them well before starting your project.
### 2. Prepare the Inner Pot
What: The inner pot is where your soil and seeds will go.
How: Using your utility knife or drill, make several small holes in the bottom of this container to allow for drainage. These holes will let water travel upwards through the wicking material.
Tips: Create holes about ¼ inch in diameter. Space them evenly throughout the bottom to ensure good drainage.
Safety: Be cautious when using a utility knife; cut away from yourself and wear safety gloves if necessary.
### 3. Create the Wicking Mechanism
What: The wicking mechanism transports water from the reservoir to the plant roots.
How: Cut a length of your wicking material—about 12 to 24 inches long. Thread one end through a hole in the bottom of the inner pot, allowing it to dangle into the outer pot once assembled. The other end will sit in the water reservoir.
Tips: Use a cotton rope or a piece of an old T-shirt as alternatives, ensuring they are absorbent.
Safety: Take care when handling sharp tools or materials while cutting wicks and avoid using anything synthetic that may not absorb water well.
### 4. Set Up the Water Reservoir
What: The outer pot will serve as your water reservoir.
How: Fill the outer container with water, ensuring there’s enough space for the inner pot to sit above it without sinking directly into the liquid.
Tips: You can use a layer of small rocks or gravel at the bottom of the outer pot if using a container with a flat bottom; it aids in drainage and prevents the inner pot from sitting directly in water.
Safety: If layering rocks, make sure they are evenly distributed to prevent tipping or instability once the inner pot is placed.
### 5. Add Filter Cloth or Coffee Filter
What: This will prevent the soil from escaping through the drainage holes.
How: Cut a piece of filter cloth larger than the inner pot’s base. Place it on the bottom of the pot, covering the holes you created.
Tips: If you don’t have filter cloth, coffee filters will work just as well.
Safety: Ensure that no parts of the filter obstruct the drainage; you want a balance between drainage and soil containment.
### 6. Fill with Potting Soil
What: It’s time to add some life to your garden!
How: Fill the inner pot with potting soil, leaving about an inch of space at the top to avoid soil spillage when watering.
Tips: Press the soil gently but firmly to remove air pockets and stabilize the potting mix.
Safety: Avoid overfilling; soil can spill during watering and create a mess, leading to slips or falls.
### 7. Plant Your Seeds or Seedlings
What: Now that the soil is ready, it’s time to plant.
How: Follow the instructions on your seed packets for planting depth and spacing. If using seedlings, gently remove them from their original containers and place them in the new pot.
Tips: For herbs, you can often plant several seeds or seedlings in one pot. Follow spacing guidelines to ensure each plant has room to grow.
Safety: Be gentle with the roots of seedlings. Avoid overcrowding plants, as they may compete for nutrients and sunlight.
### 8. Final Assembly
What: It’s time to put both parts together!
How: Place the inner pot into the outer pot, ensuring the wicking material is securely in place, with the end submerged in the water reservoir. Ensure that no part of the inner pot is touching the water directly; it should rely on the wick.
Tips: Adjust the wicking material as needed, ensuring it can draw water efficiently without blockage.
Safety: Be cautious when lifting and positioning both containers to avoid spills.
### 9. Water and Add Fertilizer
What: Establish your plants' foundations.
How: Filling up the outer reservoir with water and add a balanced fertilizer diluted according to package instructions into the water for strong initial growth.
Tips: Monitor the water level and refill when necessary. Always check for excess fertilizer buildup in your soil.
Safety: Handle fertilizer with care and follow instructions to avoid any health risks or environmental damage.
### 10. Care and Maintenance
What: Your self-watering herb garden is set! Now for regular care.
How: Place it in a sunny spot, ideally where it can receive about 6-8 hours of light per day. Monitor growth and adjust water levels as needed.
Tips: Rotate your plants every few weeks to ensure even growth. Watch for pests, and remove any dead and dying leaves.
Safety: Keep gardening tools stored safely away, especially if you have small children or pets. Always wash your hands after handling dirt and plants.
Troubleshooting Common Issues
Even the most well-planned gardens can face challenges. Here are some common issues and their fixes:
1. Spider Mites or Aphids
Problem: These pests can infest your herb plants.
Solution: Use insecticidal soap or a natural remedy like a mix of water and dish soap. Spray the affected areas regularly until resolved.
2. Drooping Leaves
Problem: This can occur due to overwatering or underwatering.
Solution: Check the soil moisture. If overly wet, adjust your watering frequency and ensure proper drainage.
3. Seeds Not Germinating
Problem: May arise from overly compacted soil or insufficient light.
Solution: Loosen the soil and ensure your herbs are receiving adequate light. If necessary, move your garden to a sunnier location.
4. Stunted Growth
Problem: Plants may not be thriving due to lack of nutrients.
Solution: Add a diluted, balanced fertilizer according to package instructions to provide additional nutrients.
5. Fungus on Soil
Problem: Excess moisture or lack of air circulation can cause mold to develop.
Solution: Reduce watering and improve air circulation around your plants.
Conclusion
Creating a self-watering indoor herb garden using repurposed plastic containers is an accessible and rewarding project that not only promotes sustainability but also enhances your cooking with fresh ingredients. By following the outlined steps, you can turn everyday plastic waste into a thriving herb garden that’s easy to manage, even for beginners.
Remember, variations on this project can include using different container shapes and sizes, or experimenting with various herb combinations. Maintenance involves regular monitoring for water levels and pest management, ensuring your herbs continue to flourish.
Take pride in your indoor herb garden and enjoy the flavors and aromas of your freshly grown herbs. With a little love and attention, your kitchen garden can thrive and inspire you to cook healthier, tastier meals.
