Whiskey barrels provide, durable, heavy and rustic environments to display plants, including small aquatic types, too. The key is a leak-proof barrel positioned where the plants receive ample sunlight and warmth. Use dwarf plant selections grown in submerged containers in the water of the barrel; use restraint in plant numbers to avoid getting get leggy plants or a weedy tangle. Barrel water that is shaded and cooled by vegetation doesn't promote algae growth.
Find a level site to rest the whiskey half barrel that receives at least four to six hours of direct sunlight. Locate the barrel near a water spigot for easier maintenance.
Place a bubble level over the rim of the whiskey barrel in several directions, ensuring the barrel is in a good location. Place additional soil or wooden shims under the barrel to ensure levelness.
Line the barrel with a plastic, PVC or vinyl liner to retain the water in the whiskey barrel.
Place the waterproof liner in the barrel. Rigid resin form slides readily into the barrel and you immediately fill in with water from the garden hose. PVC or plastic liner must be laid gently into the base, centering it, so there is enough liner to reach the top edges of the barrel.
Begin filling the barrel with loose-fit liner with water from a garden hose. Let it be a slow-paced fill so you can monitor the liner as it is pressed into place in the barrel as the water level increases. Supply a little excess liner as the barrel fills so it is not stretched tight, potentially weakened, as the water pushes the liner into the barrel's shape.
Stop the water flow when the water level reaches 4 to 5-inches below the top rim of the barrel.
Carefully trim away excess liner from the top of the barrel, so that 2 inches of liner extends evenly past the top rim of the barrel. Use an utility knife for thick PVC lining or a heavy duty scissors on plastic. Do not worry about folds that comprise the edge of the liner, as the water will help flatten them once further filling occurs.
Resume filling the barrel until the water level is 1 inch below the top rim.
Hold the liner edges down atop the rim of the barrel and staple them into the top wooden rim with the staple gun. Fold and flatten the edges as desired as you staple for a neat edge but do not stretch the liner. Never drive a staple on the inner vertical surface of the liner wall, always staple on the rim top or outside of the wood barrel slats.
Adding Aquatic Plants
Purchase only one containerized aquatic plant for the whiskey barrel, preferably housed in a black plastic container that is no larger than three gallons in size, or 10 inches in diameter. A dwarf papyrus, sweet flag, or dwarf waterlily makes a perfect plant choice.
Remove some water from the whiskey barrel with a large glass and pour the excess into a nearby five gallon pail. You are removing water to prevent run-over once the aquatic plant's container is added and displaces water.
Slowly submerge the aquatic plant into the whiskey barrel, allowing water to soak in through the container's bottom. Gently slant the container top so water gently begins to wet the soil top and doesn't wash away if you quickly submerge or drop the container to the barrel bottom.
Ensure the top of the soil of the submerged plant is no more than 6 inches below the water's surface. This depth provides amply light for the plant. Consider placing a couple bricks or an inverted plastic pot on the barrel's bottom and resting the aquatic plant atop that for the correct depth.
Add water back to the whiskey barrel from the five gallon pail until the water level is back at 1 inch below the barrel's rim.
Place two to five sprigs or rosettes of floating aquatic plants on the water's surface. Add enough floaters so no more than one-half the water's surface is covered. Some plants to considered include duckweed, water lettuce, parrot's feather or water hyacinth.