In some parts of the country, in-ground gardening can be a challenge. The soil can be full of microscopic worms, called nematodes, that feed on plant roots. Other soil pests include mole crickets, beetle grubs, ants and moles. Weeds are another challenge. Throw in problems with keeping plants watered, fighting off rabbits and such, and it’s a wonder we enjoy gardening so much!

Hydro beds

You can use a variety of containers to build your floating garden, including plastic play pools and lined raised beds.

Photo Credit: Don Goode

Drill cup holes

Drill or cut holes in the Styrofoam to hold the cups that will keep your plants afloat.

Photo Credit: Don Goode

Notch cups

Cut three notches into the bottom of each cup so the roots can access the water solution.

Photo Credit: Don Goode

Fertilizer materials

There are a number of fertilizers you can mix with water for your floating garden – be sure to use one with a blend of major and minor nutrients for the best results.

Photo Credit: Don Goode

Add plants

Once the cups are in place in the Styrofoam, just add your plants.

Photo Credit: Don Goode

One way around all these problems is to make a floating hydroponic garden. By definition there’s no soil involved – just plants growing in a nutrient-rich water solution.

Of course, there’s more to it than just tossing a plant in some water – but growing plants hydroponically is surprisingly easy:

Start by selecting your container. You can use any with walls measuring at least 6 inches high. It could be a kiddie pool, 5-gallon bucket, plant container without drainage holes, or a homebuilt wooden frame lined with plastic. (Just be sure to place it in a sunny spot in your garden that meets the light requirements for the plants you wish to grow.)

Then cut a 2-inch-thick Styrofoam sheet into a square or circle that’s a little smaller than your container’s opening. (This allows the Styrofoam to float up and down with the hydroponic solution.) Put some holes in the Styrofoam so your plants’ roots can get to the water. A 2½-inch arbored hole saw works great for this – the tool has a normal drill bit surrounded by a column of metal with saw teeth on the edge. (If you don’t want to invest in a hole saw, you can cut holes using a knife or keyhole saw.) Space your holes 6-12 inches apart, depending on the plants you’re growing and your container’s dimensions.

Next, you need something to hold the plants so they don’t fall through the holes. You can use a commercially available plastic mesh cup or a 12-ounce foam drink cup with three notches cut in the bottom. (The notches allow the plant’s roots to find their way into the solution.) Insert the cups into the Styrofoam float so the bottom of the cup just protrudes through to the other side.

Fill your container with the nutrient solution. For every gallon of water add the following: 2 teaspoons of fertilizer that readily dissolves (like Miracle-Gro®), 1 teaspoon of Epsom salt (this supplies magnesium) and 1 tablespoon of a calcium source such as liquid blossom end rot treatment (available at garden centers). Mix and pour batches of this solution until you’ve filled your container to within 3 inches of the top. (This allows room for the floating 2-inch-thick Styrofoam sheet.) Place the floating sheet with its inserted cups onto the solution.

Now you’re ready for the plants. This floating hydroponics system works well for leafy vegetables like lettuce and most herbs. Marigolds and zinnias also do well. Peppers and broccoli grow great, too, but they do get top heavy and fall over. (You can support these top-heavy plants with a collar made of welded wire mesh, or hardware cloth.)

To “plant,” wash the soil off your transplants (either grow your own or buy starter plants from a garden center). This cleaning reduces root rot problems later on. Now insert your plants into the cups so the roots are just lying in the solution at the bottom of the cup. (There’s no need to pull the roots through the cup holes – they’ll grow into the solution on their own.)

And that’s pretty much all there is to it – with the exception of changing the solution monthly to avoid nutrient imbalances, your homemade hydroponics system should be relatively carefree. (You can even use the old solution you’re changing to water other plants in your garden or landscape!) Once you’ve harvested your crop, be sure to wash the Styrofoam float and the container with a bleach solution to get them ready for your next round in your hydroponic floating garden – and enjoy!