Planting the marginal shelf

The Pond at Hillside

Planting the Marginal Shelf

The marginal shelf is a crucial part of any pond, allowing you to soften the edges with considered planting that will also provide fantastic habitat for wildlife.

The marginal shelf is a very versatile zone in terms of the range of suitable plants available. I'll share some of my top plants for use in this key zone, and how these might be positioned.

Plants for the Marginal Shelf

The marginal shelf, which slopes away for about 150 cm and then drops off severely, means this section is for plants that like to have their feet submerged and that grow up through a shallow depth of 22–30 cm.

The plants I'm using on the marginal shelves are:

• Lesser reed mace (Typha angustifolia).
• Marsh marigold (Caltha palustris).
• Greater spearwort (Ranunculus lingua).
• Japanese skunk cabbage (Lysichiton camtschatcensis).
• Arrowhead (Sagittaria sagittifolia) – this forms a small corm that will sit deep in the mud but sends up beautiful, jagged leaves. It flowers later in the season.
• Flowering rush (Butomus umbellatus) – this is a bit like a pink agapanthus, with tall flower stems in late summer. This is great for wildlife in terms of extending the season beyond the meadows, and will overlap with the purple loosestrife on the banks, which flowers in late July/August.

Size of Plants

These plants all come in different sizes. I'm using 9 cm pots for things like the lesser reed mace, but other things that grow very fast can be put in as smaller plants, like superplugs.

• Superplugs provide just enough of a flowering rush to get things going now that the season is on our side and summer's ahead. Within three months, they'll already be providing interest.

Species-Specific Planting Considerations

• Lesser reed mace (Typha angustifolia) – this will grow very fast, so I'm only using about five plants on this marginal shelf, which I'm spreading out quite far apart. I gently push them into the mud to enough depth that they won't be loosened by ducks.
• Marsh marigold (Caltha palustris) – I'm choosing slightly shallower depths for these, which will see them sit right on the edge, just below the waterline, with warm mud coming up around them.
• Greater spearwort (Ranunculus lingua) – this is quite a sculptural shape with beautiful tall yellow buttercup flowers, so I'm placing it against the stone so I can enjoy those forms. I'm planting them just in the shallowest water.
• Arrowhead (Sagittaria sagittifolia) – I'm putting these alongside the wall as well, so that we've got some excitement created by its sculptured leaves against the dry stone.
• Japanese skunk cabbage (Lysichiton camtschatcensis) – I'm putting these against the stonework where the spring emerges, to create more drama there with their large leaves and white flower spathes. They'll sit just above the waterline with their roots going into the water.

Introducing Submerged Aquatics to the Pond

The submerged aquatics are the final planting layer to be introduced into the pond. I'm using hornwort, a native oxygenating weed, which will pump oxygen into the pond to provide it with a balanced ecology that is sustained by healthy, oxygen-rich water.

Hornwort has no roots, so I simply float it in the water and let it move around to find its own preferred level and position.

Further Resources

Read more about how I created and then planted up our pond here at Hillside in our blog:

https://digdelve.com/the-pond/

https://digdelve.com/planting-the-pond/

Plant Directory

• Typha angustifolia
• Caltha palustris
• Ranunculus lingua
• Lysichiton camtschatcensis
• Sagittaria sagittifolia
• Butomus umbellatus

Your Assignment

Quick Checklist for Planning and Installing a Good Pond

• Have you got an open space out in the sunshine?
• Do you have a way of providing water to the site?
• How will you line your pond? Will you need a plastic liner, or are you able to use a non-plastic alternative, such as Bentonite or puddled clay?
• Does your design incorporate some shelves suitable for planting, and a central depth of at least 75 cm?
• Does a naturalistic pond or an ornamental pond best suit your context? Will you use predominantly native or ornamental plants?
• What might you consider in terms of water features or focal points?
• Have you thought carefully about where you want your plants before committing to planting?
• Have you got a suitable oxygenating weed, and checked that you're not using any invasive species?