Self-watering Container Garden

222K78255

Intro: Self-watering Container Garden

I made a completely portable garden that is self-watering. Each container has a water reservoir in the bottom that keeps the soil moist, and there's also a hole so excess water will drain out.

Tidy Cat kitty litter container (38 lb size)

4" perforated corrugated drainage pipe

1-1/2" PVC pipe

Potting soil

STEP 1: Create a Water Reservoir

Cut a piece of 4" perforated corrugated drainage tile to length to fit the length of the container.

Cut a square notch in one end to fit the 1-1/2" PVC pipe

STEP 2: Drill Overflow Hole

Drill a hole through the side, 4" from the bottom.

STEP 3: Cut the Fill Tube

Cut the 1-1/2" PVC to length

STEP 4: Assembly Time

Put the parts together as shown, add dirt, start planting!

STEP 5: Watering

Add water via the fill tube until water flows out the overflow hole.

49 Comments

At the end of last season, I dumped all of my containers in the driveway, pulled out all the root mass, mixed in a bag of compost, and put all the dirt back in the containers, and put the lids on.

While I had everything torn apart, I redid some of the buckets to match these instructions, since I had changed the design a couple times (size of reservoir, location of holes, location of fill tube, etc.)

All of my containers are dry and ready for planting, as soon as it's warm enough. I might even take them to the garage and get them going early. :-)

Now that they've had some time to grow, how do you find it compares with your previous setup?
Is the corrigated pipe the only thing that holds water? How does that work if it has holes? I've seen EarthBoxes but they have a barrier like a perforated piece or something to separate the water reservoir from the soil. Are you packing your soil/soilless mix all the way around the corrugated pipe and doesn't the water leave the corrugated pipe virtually as quickly as you pour it down the pvc pipe?
One way to look at is is: If you do starter plants from seed you place all the little pots in a basin or tray of water with only the bottom of the pots in the warter wicking the water up to the seeds at the top then they sprout after a few days and you transplant after they have 3 leaves!
The pipe makes a reservoir, and the perforations allow the water to seep into the adjacent soil. When I fill the pot to the overflow hole, there is about 4" of water and wet soil in the bottom. The water wicks thru the soil over time, so all of the soil is damp, and the pipe is mostly empty. This allows for oxygen at the root level.
The corrugated pipe has holes in the sides, so the water flows out to the soil on the sides, which then wicks the water up to the roots. The pipe creates a cavity to hold ~2 liters of water, and the hole in the side keeps the entire box from overflowing in the rain.
If you locate the drain hole directly behind the fill tube above the level of the irrigation tube, it won't clog, and dirt will not escape as it's blocked by the tube. I was going to use a small piece of screening hot glued to the inside, but it doesn't need it if the fill tube is in front of it. I also cut the fill tube at a 45 degree angle at the bottom inside the irrigation tube.
So is one overflow drain hole enough or should several be made?
One 1/2" hole is plenty. I've never had one get plugged.
Thank you. I'll be making these and getting them ready for spring. Are some vegetables better for this than others?
I have had really good luck with lettuce, spinach, and herbs. I also had good luck with cherry tomatoes (I slightly bent the legs of a square tomato cage to fit the bucket.)

One more idea might be to fill around the drain pipe with some light weight lava rock to increase the opportunity for soil O2, better drainage and a little more water space. You could also increase soil O2 by occasionally watering overhead which serves to flush and pull in O2.

I totally dump the containers out every Fall, remove all of the root matter, add new peat and soil as needed. I've never had significant soil in the drain pipe, so rock filler isn't needed.
I've found that the overflow hole well let the potting soil run out along with the water, especially if there is a hard rain. What I did was take some pieces of mosquito netting and used silicone sealant to attach a small piece of netting on the inside of the bucket over each overflow hole before filling the bucket with soil. This allows the water to drain out but keeps the soil in. You can also use old pieces of window screen if you have it. I didn't drill just one hole because they can easily clog up with clumps of roots or other plant matter and then the plant can become waterlogged. I put a series of holes all the way around.

Put a porous sleeve over the black water pipe so the dirt will not fill the storage pipe. Also, mix 1/3 compost, 1/3 vermiculite and 1/3 peat moss (Mel's mix). This is a great soil combination for the vegetables. Look into Square Foot Gardening for soil mixture and plant spacing.

Yes, I read Square Foot Gardening years ago, but I didn't follow it exactly. In the Fall, I dumped out all the containers, picked out the roots/plant matter, then reassembled the containers. I added a bag of manure to the existing soil mixture, mixed it thoroughly, and refilled the containers.
Oh, and I've never had a significant amount of soil enter the corrugated pipe, so the porous sock has not been necessary.

I'm an IL Master Gardener & use cheap 18 gallon tubs from Walmart as well as kitty litter buckets like this. You must use the white PVC pipe as that does not leach toxic chemicals & is designed for water system use in a home. Cut the bottom of the PVC at an angle so the water flows easily into your reservoir. The drainage tile is already perforated so water will flow out slowly. Best to cover it with cheesecloth or some other cloth to keep the dirt out. I fill the PVC pipe until it stays full for a while. But you must drill a drainage hole in the side of the tub just above the height of the reservoir. If water starts coming out the drainage hole you know your reservoir is full. Try filling daily or every other day until you get to know how often it will need filling as that will depend on weather and heat. You can grow just about anything in these tubs - I've grown tomatoes and beans with a trellis or cage. Melons also do well when supported with old pantyhose. Herbs do very well - I had one bin last summer with various herbs on my back porch right outside the kitchen door so it was handy to cut a few for cooking. A few starter potatoes will also work well, but start them low and add soil as the plants grow. The diaper pellets are a great idea to hold moisture into the growing soil and they are much cheaper than a bag or box of pearlite. One big box of disposable diapers will give you enough pellets for a lot of tubs. Happy Gardening!

Thanks for the feedback.

I dump out and rebuild every bucket every fall, and keeping soil out of the corrugated pipe has never been an issue. The pipe doesn't fill with mud. I suppose the black pipe might not be as healthy as the white pipe, but it is designed to be in the soil for decades without breaking down, so I doubt it's leaching much. Plus, any leaching would have to pass through the soil, and roots, and plant before reaching the fruit or vegetable.

Whats the difference between watering your plants every day or two and watering your reservoir every day or two? If the soil does not touch the water how does it get moist all the way through? Are you not concerned about root rot, and plants going fungal which can severely diminish crop outcome if not kill the plant? Isn't a plant in a pot already a portable garden? Cool idea, I just don't see the point. Maybe I missed something. I'm not an officially titled "Master Gardener" but I am a professional nursery worker.

More Comments