The Rain Gutter Grow System takes container gardening to a whole new level. It is a low-maintenance, mass growing system that can grow many large and small crops at once. Plants are grown inside of large or small containers and fed water and nutrients from the rain gutter, which is maintained by a float valve and connected to a well, rain barrel, garden hose, water tap, etc.
This design is similar to the wicking bed, in that it uses a wicking cup which dangles below the planter bed down in the rain gutter. And, similar to the wicking bed, it uses capillary action to lift the water from the reservoir and up to the plants. When the net cup is in the rain gutter, making contact with the water, the capillary action will cause the water to absorb up into the potting mix. The soil then automatically becomes moistened, and the plants take water as they need it.
However, unlike the wicking bed, in this design multiple units may share a single reservoir, which is extended across a long horizontal surface, to offer more complex designs for mass-production of crops. This allows you to fit many buckets on a single rain gutter, and multiple gutters can be fixed atop a surface like a driveway, yard, or table. This offers near limitless expandability, and makes it easy to add new planters later on. You can also repurpose buckets or containers of almost any size or shape, as long as you can drill a hole in them through the bottom, and they can sit steadily on top of the gutter.
For multiple gutter systems, you can attach them together using hoses or a PVC pipe and valve shut-off system. Instead of 5-gallon food buckets, you can use grow bugs or some wide plastic storage bins. For these, drill two holes, evenly spaced on the bottom, and use two or three net cups instead of one. As an alternative to the net cups, you can use any plastic tub of the same size (like those used to hold butter, yogurt, or sour cream), and use a drill or soldering iron to put holes in it to allow water to pass through.
- 2x 10-foot long, treated 2x4s
- 1x 10-foot long (vinyl) rain gutter
- 2x end caps for the gutter
- 5-gallon food buckets
- 3-inch net cups
- ½-inch or ¼-inch float valve
- Power drill and hole saw
- Scissors or knife
Take the rain gutter and mount it between two treated, water-resistant 2x4s. Use a vinyl rain gutter instead of a snap version to allow you to glue the sides onto the wood framing. Clean the gutter with PVC cleaner where you intend to glue, apply the glue, and use a clamp to hold them together. You do not need to use any specialty rain gutter glues. Just use a cheap, all-purpose PVC cement. Let it dry and glue the caps on the ends of the rain gutter. Hold it on for a few seconds until it adheres, and let it dry.
Take some ¾-inch pole barn or stitching screws, which are painted and galvanized screws with a rubber washer. Screw them into the gutter to attach it to the wood frame, spacing them about 6-inches apart. Get a plastic float valve with a ½-inch male screw and a hose or other attachment. If you have multiple gutter systems, instead of the ½-inch floater, you can instead get the ¼ inch barb float valve, which is the same as the ½-inch one, but has a smaller attachment. This allows you to use an inexpensive plastic T to chain multiple units together with ¼-inch hoses so you can water them all at once.
Once you have chosen the right attachment, drill a hole in the end of the gutter and mount it inside. Try to put it up as high as possible in the gutter to maximize the amount of water that will be maintained inside. Level the unit to ensure that water does not spill out of the gutters. Cut a few small, flat pieces of wood to attach to the bottom of the unit to help level it, if needed. If you plan to lay the gutters flat on the ground, place some used carpet on the ground underneath the gutter system to prevent weeds from growing.
Use a 2 7/8-inch hole saw to drill a hole in the bottom of the 5-gallon food bucket, and insert a 3-inch net cup in the hole. The completed bucket will lie on top of the 2×4 framing system, and the cup will sit submerged within the water. Before filling the buckets, take some fabric, like an old bedsheet (although a synthetic fabric is best because it won’t degrade), and cut it into squares big enough to fit over the net cups. Take some soil and form it into a small ball with a gloved hand, keeping the other hand clean, and drop it into the net cup. Fold the sheet over with your clean hand so that the outside of the net cup stays clean, and cut away any extra fabric. This will keep the soil from contaminating the water, but also allow the water to wick through the cup and up into the soil.
Fill the bucket with potting mix, or a soil mixture of 1 part compost and 2 parts peat moss. For every 5-gallon batch, add 1-cup of dolomite or garden lime and a handful of Epsom salts to improve soil quality. For shade-loving plants, try orientating your gutters north-south, and plant taller, sun-loving plants on the south-side to take advantage of natural shading. You can also put them up next to a wall or a building to provide extra shade to shield more vulnerable plants. For water-loving plants, like lettuce, radishes, Swiss chard, etc., you should grow in shallower buckets because the water will wick up faster, and the soil will be more moist. For deep-rooted vegetables, like carrots or beets, use deeper tubs.
Preventing algae and mosquitoes
If you’re using water from a rain barrel, or your water stays static throughout the year, then it may start to grow algae and clog up any pipes in the system. In addition, mosquitoes can get inside and start breeding. To prevent mosquitoes and algae from propagating in stale water, get a roll of long, opaque sheet plastic and roll it out over the gutter. Measure the width of the gutter and wood frames, together, and add double the width of one of the 2x4s. This will tell you how wide you need to cut the sheet.
Take the plastic, measured and cut to fit, and lay it down over the rain gutter and frame. To secure it to the frame, and prevent it from ripping, fold the extra plastic on the sides under itself to double it up. Take a staple gun and staple the sheet to the frame, keeping the material folded and held taut all along its length. Lastly, take whatever containers you will use (with the holes already drilled in the center), and place them on top of the plastic. Set them in place where you want them, and mark inside the holes using white chalk or a sharpie marker. Then, cut an X into the sheet with a knife to fit the net cups.
Modified PVC pipe gutter system
For a modified version of the rain gutter system that simultaneously reduces evaporation, and helps stop mosquitoes, instead of a rain gutter, simply use a long PVC pipe, about 3 ½- to 4-inches wide (approximately 90 mm), and cut some 2 7/8-inch holes in it down its length, at regular intervals. Space out the holes enough to fit all the containers, side by side, and ensure they are cut just large enough to hold the net cup so that it’s submerged under the water, but not so big that it falls through to the bottom. Then, attach some caps at the end of the pipe, and proceed as normally. You could even use this to create an alternative, hybrid version by combining the closed PVC pipe with the plastic sheeting to make a system that is almost completely resistant to evaporation and mosquitoes.
When plants are in a solid container, the roots will naturally grow outward, expanding until they hit the sides, and stopping at a solid barrier, unable to grow any further. Because the walls of the container are hard, the roots have no place to go, and they will circle around and bind themselves up. As this happens, the roots become bound together and create a death spiral that restricts plant growth.
However, this does not happen when using soft containers, like grow bags, or containers that have holes drilled into them. In those cases, instead of binding up, the roots grow right through the sides of the bag or holes, dry out, and fall off, naturally pruning themselves when exposed to air. As the roots grow, they sprout through the fabric holding them in, and when they detect the dry air on the outside, this tells the plant they need to make more roots, so they create more massive, fibrous, heartier, and healthier roots that take in more water and nutrients for optimal plant growth.
When using hard containers, drill some 2- to 3-inch wide holes into the sides, using a hole saw, spread out evenly all around the exterior. You can also use a laundry basket that already has holes in it, recycled or bought cheaply from a thrift store. Line the insides with a sheet of WeedBlock or landscape fabric to keep the dirt from falling out. Fill it with soil or potting mix, cut away any excess fabric from the top, and proceed as normally.
Self-Watering Hybrid Kiddie Pool Grow System
Get some re-usable Walmart shopping bags or some root pouch bags, bought in bulk, or make your own using landscape fabric. Fill them with soil or potting mix and put them in a kiddie pool.
Take a Tupperware container with the lid, about 2-inches deep, and get a ½- or ¼-inch barb float valve, and mount it through the side of the container, about ½-inch from the top. Drill some small 1/8- or ¼-inch holes around the sides of the container so that excess water will flow out. Get a garden hose adapter, sized to fit the float valve, and mount the Tupperware-floater assembly on the inside of the pool about 1 ½ inch up from the bottom.
Drill an overflow hole in the pool about 2-inches up from the bottom, right at the same height as the hole that connects the pool with the container. However, you could accidentally drill the overflow hole under the fill-line, which is the point at which the float valve closes, sealing shut, and switching off the filling action. If you drill the overflow below this point, you could lock the mechanism into the fill position, causing non-stop watering as all the extra water that enters the bed leaks out of the hole. To prevent this, drill the overflow hole a little bit above the fill-line, like maybe ¼- to ½-inches above it. But don’t go up too high, as large storm events could cause heavy pooling, generating standing waters in the bed that invite pests, algae, and bacteria. You may have to experiment with the holes you make to find the correct relative positions of all the parts of the valve system, using the particular parts available to you.
Fill the pool with the grow bags, placed closely together, but leave a little bit of space between them so air can enter and flow, as well as enough room for the Tupperware container-assembly to fit on one side. Fill in the empty spaces around the grow bags in the kiddie pool with pea gravel, river rock, lava rock, or white marble, going up about 3-inches from the bottom. Do not put gravel in the Tupperware container, but leave it empty, except for the float-valve. This will create about 1-inch of dry medium above the water level, reducing evaporation, and eliminating mosquitoes and algae. If you want additional protection, first put down some landscape fabric on the gravel, and then lay the mulch on top of it.
Lastly, fill the pool with 2-inches of water, which should be at the point when the float valve shuts itself off. Capillary action will wick water up into the bags, sub-irrigating the plants. Do not try to submerge the bags in water, or let the pool fill up more than a few inches, or space the bags too closely together, as the roots need to be exposed to air and have room to grow, dry out, and fall off.
You can modify the Rain Gutter Grow System by combining it with the Kiddie Pool Grow Bag System. The rain gutter can be partially buried underground, or covered with mulch, to prevent evaporation and pest invasion. Create openings in the gutter or pipe, create an opening with a wicking cup or another wick sticking out of the bottom of the bag, and place the bags onto the gutter, centered directly over the holes. This way, the plants grow in the bags instead of in solid containers. You can also make this system using a wood frame, rock, or concrete blocks, simply by lining them with a pond-liner, or any other water holding container.