There’s more to planting a pond than throwing things in it. You get a water lily, drop it into the water and let it die of starvation because it can’t reach the surface for light. You put an iris into boggy ground, smothering whatever else is there. It’s often all about depth, how deep is the comfort zone for each individual species? Respect their space, and you’ll have a bounty of bloom and clean water.
To visualize how the pond is layered, I made this chart (above), beginning with the saturated edge and working inward toward deeper part. Imagine it’s a habitat-building exercise… Like constructing a house for other creature; and you’ll understand its structure, or “floors,” better.
How to Plant in Different Pond Depths
Above everything are the bogs at the upper edge, an overlooked realm for moister-loving thing like water forget-me-not and marsh marigold, growing in soil that’s neither submerged nor bone-dry, but moist. They cushion hard liners and slow erosion of banks.
Below the bog area, there’s the shallow margin, home to emergent plants whose roots grows beneath the surface and who send up foliage above: things like yellow flag iris and cattails. Their presence adds vertical structure for fish to hide in and birds to perch on.
Deeper in the mid-zone are floating-leaf plant such as lotus and water lilies, which require careful placing or else their leaves will completely cover the surface, robbing underwater life of light. Too far down and no flowers, either. They’re essential to the look of the garden. As the visual guide explains, their leaves reaches skyward on long stems anchored well below to capture sunlight. This shades the water and reduces algae growth by cooling it. (Without them, the pond would of been a warm house for green scum.)
The oxygenators is Elodea and Hornwort. These plants (elodea & hornwort) are completely under water. They act like the kidneys of your system by removing excessive nutrients from the water. This prevents those nutrients from feeding unsightly algae growth. Because they rely on the water column to breathe and expand, give them room down there! See the infographic above for proper placement. You do not want them planted too deeply in muck or exposed to cold winter surface temperatures.
Chemical balance matters; this isn’t just a matter of good looks. If you have no oxygenating plants in your deeper water, you’ll have to work harder. As with all your plant, there are season-to-season changes. In spring, lilies goes shallow to warm up fast and encourage early growth. In summer, they move deeper as stems stretch longer. By fall, they get cut back, and dead leaves is removed before they rot in the tank and cloud the water. And in winter, tender plant must be moved deep into the most stable parts of the tank to protect them from freezing.
This is because a dynamic system maintains the healthiest plants throughout the year. Use aquatic baskets rather than burying pots directly in the pond floor. Then move them around as necessary: If a plant flourishes or fades, simply lift it up or down to another spot. Make sure the surface area of all floating foliage equals about half the surface area. That’s how to find the balance between light and shade.
Don’t battle the logic of Mother Nature’s zones. If each thing is where it wants to be (as in each plant at just the depth it prefers), then the whole system start to self-regulate. And your work becomes more passive watching than active doing. Voila is a garden that looks effortless (balanced and alive). That’s why it’s realy worth it, making the depths add up.
