How to build an earth box-cheap

I’ve seen multiple ways of building earth boxes and a few for sale – most of which cost way too much money. Most earth box plans are far too complicated. Some are simple, but require too many buckets. I’ve modified a design I liked, but made it to use only one bucket.

What is an earth box?

Maybe you’ve never heard of an earth box. An earth box is a self-watering soil based growing container. It holds a reservoir of water in the bottom, and draws out water into the soil through a wick. What makes earth boxes unique is that they can be used for both indoor and outdoor gardening. The plant gets plenty of water and there is almost no risk of over watering. They are great for growing almost any vegetable or house plant.

One observation I’ve made is that earth boxes work great for plant growing, but not well for seed starting. The root area remains very moist, but sometimes the top layer dries. If you are starting from seed, you will either need to get your seedlings established and move them to earth boxes, or you’ll need to lightly water to keep the top layer moist until the seedling sprouts and establishes its roots.

Materials needed.

1 – 5 Gallon Bucket and lid.
1 – Small Pot or 3 inch Net Pot
1 – Large bag of soil.
1 – 2-3 foot pvc pipe.
A drill.
A saw – jigsaw or small handsaw.
Drill bit – 1/4 to 3/8
Unibit / step drill bit
Wick – Fiber or other material
Optional – 1/2 inch grommet
Optional – 1/2 connector
Optional – 1/2 inch tubing

unibitThe step drill bit is optional, but it makes life much easier – especially if you plan to build these on a regular basis. Name brand step bits are expensive, but you can buy a two-pack at Harbor Freight for around $10 or a three pack from Amazon at the link below. These may not be as good of quality, but since we’re drilling plastic, cheap ones are more than sufficient.

A unibit / step bit is pictured at the right. It can drill holes in increments from 1/4 inch up to 7/8. Some can go bigger.

These bits are wonderful for building hydroponic gardens and earth boxes. They are especially useful when drilling holes for grommets and you don’t know the exact size. Drill small and work upward until a perfect fit is achieved.

Building the earth box.

I know it’s a bucket, but it’s still called an earth box. Maybe the first one was square.

Begin by marking the center. This will be the wick for the reservoir. In this picture, I’m earthbox1using a net pot, but you could use a small seedling pot. Some people even drill holes and run strips of cloth into the reservoir. I don’t think this is as efficient, so I’m using fiber-fill and a net pot.

I used a sharpie and outlined the pot. Then I cut the whole about 1/4 inch inside the line. I don’t want the hole big enough for the pot to fall through. 1/4 inch gives enough room for the body of the pot, but still gives a snug fit for the lip of the pot.


It’s a perfect fit!

Next, I’m going to cut the outer rim off the lid. If I cut the lid to be 10 3/4 inches, it will earthbox4wedge into the bucket about 4 inches from the bottom. This will leave room for 1-2 gallons of water. I used a jigsaw to cut as I rotated the bucket while the lid was snapped into place.

You will need to drill a starter hole in order to get the jigsaw blade started. This is a great time to drill the PVC pipe hole. Using your step bit, work the hole bigger until it’s a perfect match for the PVC pipe. Try to cut the pipe hole so that it bumps up against the edge of your rim, but not cutting into the rim. This way you will have a perfect fit when you put the top plate (inside of the lid) into the bucket.

earthbox6Now cut the lid out to make your reservoir plate.



Once the lid is ready, cut a notch into one end of the PVC pipe. This will allow water to flow freely when you fill the reservoir. If the pipe is flat against the bottom of the bucket, water won’t pass easily.


Optional Drain Plug

This step is optional. To maintain healthy plants, it’s good to change the water on occasions. Once dirt is in the box, it won’t be possible to drain the water without a bottom plug. So I like to install drain plugs. Installing grommets is where step bits are very helpful. This is a half-inch grommet, but the grommet hole needs to be right at 5/8. The wonderful thing about step drilling is that if you are unsure, you can drill a smaller hole, test it, and go one step up if needed.

Drill the hole for the grommet and insert it, tapered side in the bucket. earthbox9

The grommet should be a tight fit and a little hard to get in. A flat blade screw driver can be helpful as you work the grommet into place. Don’t use a fine blade screwdriver or sharp object. You don’t want to cut the grommet and start a leak. Once the grommet is in place, insert a 1/2 pipe connector. You could install a spigot, but we are trying to keep the cost down.

The pipe connector is a very tight fit, but you can make this a simple task with a little oil. Dip your little finger in olive oil or vegetable oil, and lightly coat the inside of the grommet. The connector will easily slide into place.


Don’t use petroleum based oils. They can corrode the rubber and you don’t want to contaminate the water.

Seal off the fitting with a plug cap. You could also use a small piece of 1/2 rubber tubing. earthbox12To make an end cap with rubber tubing, cut a piece about 3 or 4 inches long, fold one end back over the tubing and tighten it down with a plastic tie. This will make a perfect seal. You should end with something like this. To drain, pull off the plug.



Now drill two small holes below the lip of the bucket. Place the plate into the bucket with the pipe and strap it in place with a tie.


The final assembly should look like this:


Very important! Once you see exactly where the pate will rest, drill a small hole just below the plate. This will serve as overflow protection. If the reservoir overfills and the soil becomes saturated, the plant will suffer and eventually die. Roots need oxygen. That’s why loose soil is important. It’s also why plants die when over watered. If you have an overflow hole, the pot can never be over filled and the plant will never be over watered.

Now fill the net pot or seedling pot with fiber.


This will act like a wick. It will absorb from the reservoir and the soil will draw from the fiber. It will also act as a filter and keep dirt out of the reservoir.

Now fill 3/4 way with soil. Add some tomato tone, insert the plant, and fill to the top.earthbox13

Use the pipe to fill the reservoir. A funnel helps if you’re adding nutrient. Otherwise, just use a hose to fill the pipe. Water until you see something coming out of the overflow hole.


For tomatoes, Tomato-tone provides the necessary calcium and other nutrients needed by the plant. Before planting, circle the outer edge with tomato tone so it will be available when the roots reach out for it. You can also go a step further and mix in a gallon of hydroponic solution and pour it into the reservoir. Don’t make the solution too rich and only apply the solution once. After this, replenish with water.

An earth box will keep your plants constantly watered with healthy levels of moisture. Once a week, refill the reservoir with fresh water until you see it trickling out of the overflow hole.

The earth box can be used to grow either indoors or outdoors. It also gives you the ability to move your plants inside when a frost is expected.

Final Note

If you want to cover your soil to preserve water or keep pests and weeds out, use the rim of your lid and a plastic sheet. The lid can snap the plastic sheet securely. Then you can cut a slit and plant your tomato while leaving the rest covered.

In hydroponic systems, it is also very important to use a bucket that doesn’t allow light to pass. In earth boxes, you can get away with a little light if you change your water regularly so it doesn’t stagnate. These silver buckets from Lowe’s work great. The ideal bucket is black, but gray buckets also work fine.

A white bucket or one that allows a lot of light to pass through will have algae problems. Algae is not your friend. If you want to go all out, here is a link for black 5 gallon buckets.

The lid and bucket are sold separately. If paying $20 for a bucket seems steep, go to Lowe’s and buy their house brand silver bucket and lid. Both will cost you less than $5 total. You can also buy a white bucket and paint it black. Any lid will do since the parts will be inside the bucket.


Net Pot: $3.37 for a pack
Grommet and connector: $1.65
Fiber: $5:73
PVC Pipe: $4.00
Bucket: $5.00 at home improvement stores
Total: $19:97

If you build a second box, the fiber, net pots, and PVC pipes are ready to go. The cost of a second bucket would only be $6.65.

Eddie Snipes 2012
Follow me on Twitter @SuburbanGarden1

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How to build an earth box-cheap — 8 Comments

  1. Banana Box Gardening

    This is a modified version of container gardening in that you use biodegradable cardboard boxes instead of a solid plastic container to do your gardening in. Empty banana boxes come with both a top and a bottom section and have an opening in the middle of each. They can be used inside one another to create a double walled box or separately as individual boxes.
    Banana boxes can be obtained free from Walmart and Payless from the produce section just for the asking. Ask any of the clerks stocking the shelves with fresh produce if you can have a couple. They are happy to oblige and will bring you as many boxes as you can load in your grocery cart. The boxes are ideal for a small kitchen garden at the back door of every home. Such a garden can introduce the family kids as to where their food comes from as well as recycling the household waste organic material.
    Place the box or boxes in a permanent location in the garden. They cannot be moved after filling. The site should have 6 or 8 hours of direct sunshine available sometime during the day. Cover the bottom of the box with a half dozen layers of newspaper or pieces of cardboard; anything biodegradable. This will smother the grass or weeds that might be growing under the box. Give it a good soaking of water. Next add 2 or 3 inches of peat moss on top of the moistened paper bottom. On top of this, add a layer of organic matter such as kitchen waste, banana peels, coffee grounds, green grass or manure of any kind. This will supply the nitrogen, microelements and bacteria necessary for the organic material to start the decaying process. Keep everything moist so it starts decomposing as soon as possible. Earthworms will soon congregate under the decaying cardboard, which will help to enrich the soil.
    Next fill the box with a carbon material such as dried leaves, straw or old hay and again wet every thing down; now tamp it down good and cover with compost. If compost isn’t available, use a good potting mixture available at any nursery store. There is a difference in potting soil and potting mix sold in stores. Potting mix is preferable as it is composed of micro chemicals that plants need, as well as peat moss and vermiculite in the right proportions. Don’t use soil of any kind you dig in your yard as it has too much clay that packs down and limits the oxygen that plant roots require. This soil also harbors disease pathogens and weed seeds that linger in the earth. You should be able to poke your index finger all the way down in the light, fluffy soil to the knuckle. Your box is now ready to plant.
    An easier way to fill the box (although more expensive but more satisfactory) is to purchase a bag of container potting mix, such as Pro-mix from Menards for each box. This soil mixture has the correct proportion of peat moss, vermiculite and compost to grow anything. However when growing tomatoes, it is best to add a cupful of ground limestone to counteract the acidity of the peat moss. This will prevent blossom end rot.
    Two tomato plants can be planted in each box. Other boxes can be planted with whatever vegetables or flowers you would like to plant. Scatter carrot seeds in one box. In another disperse lettuce seeds and in another, pepper and egg plants.
    To grow potatoes, set a banana box in a cleared area and place a sprouting potato on the soil surface in the center of the box. Don’t bury it. Fill the box with loose straw covering the sprouts. The potatoes will send up green shoots through the damp straw and roots will grow into the soil below. You keep adding more straw as it packs down and the sprouts grow taller. After the potato vines turn brown in the fall, the potatoes are ready to harvest. Just lift the box and the new potatoes will be lying on the soil surface. No need to do any digging,
    When the cardboard boxes are kept moist over a period of time, I have noted that the long side has a tendency to bulge out as the inside compost settles. To remedy this, wrap the boxes with several layers of clear strapping tape covering the ventilation and hand holes in the boxes.
    In the fall, after the banana boxes have fulfilled their mission, the decayed remains can be scraped up and added to the compost pile for use in next year’s garden.
    Vegetables can be grown with this system on an outdoor deck or concrete patio provided it is exposed to all day sun. Keep experimenting to find the best way to fulfill your own personal gardening conditions. That is the only way to learn!

  2. Pingback: Tomato Earth Bucket Gardening Vegetables

  3. Pingback: Tomato Earth Bucket Gardening System

    • Some of my buckets are 6 years old and still in use. And when they fail, I’ll fork out another $4 and do it again.

  4. I have attempted making this bucket more than once & have yet made a lid that fit w/o teetering from side to side allowing the soil to get into the water reservoir. I tried cutting 4 PVC pipe supports but that was impossible to get the supports cut perfectly.

    The bucket lid must be cut precisely to fit inside the bucket for the proper fit & support. The lid may wobble, tip to one side & etc unless cut to fit precisely. The 10 3/4″ cut may work for most 5 gallon buckets but some 5 gallon buckets are a tiny bit wider & shorter versus slimmer & taller which requires a different size cut.

    I have made many buckets using the UF Bucket Brigade instructions that use 2 buckets but dislike wasting a bucket to make it. I am a FL Master Gardener & familiar with the Earth Box process.

    I really would like to know the exact diameter of the cut lid to fit 2 gallon & 3 gallon buckets.

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