“A garden should be a nice place to visit year-round,” says Mark Gibson of Green Thumb Garden Center in Little Rock, which he helms with his sister, Marlene Murphy. As specialists in water gardens containing aquatic plants and fish, they have a creative and unique solution for season-less beauty: floating island planters. Comprised of a buoyant foam base that holds potting soil and plants, a floating island ensures there’s something alive and green in outdoor spaces even when land plants begin to wane, from the peak of summer to the dead of winter.
A floating island is surprisingly easy to build and maintain, and is ideal for anyone with a pond or area of water that needs some attention. And in a koi or fish pond, its benefits extend to providing shade and protection for fish, and oxygenating and purifying the water as well.
Here’s how to create your very own floating garden:
1. One spray can of Rockin’ Foam
2. Potting soil with no additives
3. Variety of plants. Shown are yerba mansa, water canna, parrot’s feather, lobelia, variegated sweet flag and red hygrophila.
Use black closed-cell Rockin’ Foam for your base, being extremely careful not to let the foam touch your skin. Spray two layers to construct a round or natural looking shape about 12 to 14 inches wide; narrow shapes are unstable in water. Leave holes so plant roots can grow through for self-watering. Allow the foam to set for at least 20 minutes. After it sets, spray additional foam around the rim of the base, creating a barrier to hold in soil and plants. Allow the foam base to dry overnight. Once it has dried, attach a rope long enough to anchor the floating island to the bottom of the water.
Now it’s time to add soil and plants. Find potting soil without additives such as fungicides and fertilizers that may harm fish, and select all-season plants that will fare well given the amount of sun and shade you have. Begin by spreading a layer of potting soil around the base. Murphy suggests situating taller pants near the center for stability and likes to include creeping plants, such as parrot’s feather, which will grow out over the base and make the island appear fuller. All-season plants include begonias, impatiens, petunias, marigolds and coleus. Finish with more soil as needed or a layer of moss to camouflage the foam base. For an anchor, attach the other end of the rope to a rock or brick and drop in the water. The plants should be lush and full within two weeks.
Care and maintenance:
Floating islands are lower maintenance than most gardens. They are self-watering and self-feeding in water with high amounts of ammonia. If plants begin to fade, simply use a fish-friendly pond fertilizer. Gibson and Murphy suggest adding an air pump and airstone to the water, which will keep the water circulating and prevent freezing during the winter months, ensuring a beautiful garden space throughout the year.