Plan the pond's shelf depths carefully:
It is the weather for planning this year's new pond - consider:
1. how to build a pond to suit the plants you want.
2. what makes water plants different to other plants you grow.
Construct a pond with a choice of depths of water - each depth has plants that suit it.
- Shelf 3 - the deepest area of the pond 45cm+(18"+) but no deeper than 75cm (30"). Plants will either remain fully submerged like oxygenating plants or send up leaf stems from the deep water like waterlilies.
- Shelf 2 - a depth of 23-44cm(10-17") for certain Pond waterlilies and the upright growing emergent plants that require protection over their crowns in winter like Pontederia cordata lancifolia and Caltha palustris Stagnalis.
- Shelf 1 at 15-22cm(6-9") is for the majority of upright emergent pond plants like Alisma plantago-aquatica, Butomus umbellatus, Iris versicolor, Pontederia cordata where the top of the planted basket is within a maximum 5" inches of the top of the water or for Dwarf waterlilies.
- Shelf 0 is a shallow shelf 13-15cm (5-6") so the water surface is within 2-3" inches of the top of the planted basket. That puts the crown of the plant near water level where it can have ice around the top of the basket in Winter. Many are horizontally growing(rafting) plants like Mentha aquatica, Myosotis scorpioides, Rorippa nasturtium aquaticum, Veronica beccabunga.
- plants have crowns that can be grown in wet mud in a waterlogged bog area or stream side with the plant crown in ice or frost. For example - Anemopsis californica, Caltha palustris, Iris pseudacorus, Veronica beccabunga.
Placing the right plants in the right water depth is important.
If some are too shallow they will be caught in the ice and may die.
Or if some are too deep they will not survive either. So build your pond with:
- Plenty of shelf space at different depths.
- Flat shelves for the plant baskets so they are stable.
- An area of slope from the top shelf to the rest of the garden for wildlife to climb up.
- Piles of cobbles or stones up the sloping top area to protect liner and keep it upright above water level.