by Harriet Bond
(San Francisco, CA, USA)
So you have finally got the garden pool built, now it’s time to think about stocking it….but wait, before you rush off to the Garden Store, please read this two part article. To read part one please click here.
• Plants that do not root in soil are simply placed loose in the water.
• Plants that root in the bottom, such as the marsh plants and those with floating leaves, can be set directly in the bottom of the pool (if there is soil there) or they can be planted in submerged containers.
• If you use containers, be sure they are large enough. Underwater plants with roots and plants that form runners are placed in large, shallow containers. Containers for larger, and especially for flowering plants, such as flowering rush, lobelia, and the various irises, should be a good 12 inches (30 cm) across.
• The so-called bank planting mats with plant pockets are especially practical and versatile. Using these mats, one can easily plant even steep banks, separate a marshy area from the regular garden, or hide the plastic or fiber¬glass edges of pools from view with a carpet of plants.
• Organize the plants in clusters with coordinated colors. Take into account the flowering periods. With a little bit of care, you can choose plants with a view to having something in bloom and adding color to your pool all summer long.
Important: Always place the rhizomes of water lilies horizontally; never plant them vertically into the ground.
Fertilizing: Fertilizing water plants introduces unneeded nutrients into the pool. Pool plants manage perfectly well without being fertilized. Only freshly introduced water lilies benefit from a small dose of a special fertilizer for water plants.
Care of Plants: For most of the summer the pool gardener can relax. All that is needed now and then is to tidy things up a bit or thin plants that are spreading too much. In the fall there are some chores to tend to, depending on the kind of pool you have. You will also find practical advice there on how to keep your pool healthy, how to keep algae from taking over, and what to do if plant pests or diseases turn up.
The Right Soil
Avoiding an excess of nutrients is also a primary concern when choosing plant soil. No matter whether you add soil to the bottom of the pool or whether you set your plants in containers, the soil must always be low in nutrients.
What seems to work well is a mixture of clay and sand in a pro¬portion of 1:3 or 1:4, that is, mixing together one part heavy clay soil and three or four parts sand. You can buy sand at gardening or building supplycenters. A grade of up to 3/32 inch (2 mm) is recommended. Most firms will deliver the sand at least as close as your garden gate.
You can add this mixture of clay and sand to the entire bottom of the pool—about 4 inches (10 cm) deep or deeper in places—or use it as soil for plants set in containers. All plants that require neutral soil but don’t mind a little lime thrive in this mixture.
Some marsh plants, though, have special soil requirements and need more acidic soil (containing some peat). For them you have to add peat to the soil mixture—generally in the proportion of 1:1:1. g Since peat can have an adverse effect on the pool water, it is best to 1 put these acid-loving plants in the marsh bed. There, growing in containers, they can be combined with other plants that require more alkaline conditions.
You can also cover the pool bottom with washed sand or gravel.
You are always safe if you use soil that is unfertilized and free of toxic chemicals. Be very careful if you use fertilized soils—don’t add fish until 2 or 3 weeks after the plants have been established. Fish do not tolerate any fertilizer at all.
Never use the topsoil (the upper level of the earth you have excavated to create the hole for the pool) or humus from your compost pile in the pool. They are too rich in nutrients.
If you missed out on part one of this article, please click here.