Remember the surface cover planting of your pond should be two thirds of the water area. The quickest way to achieve this is by using deep water pond plants like waterlilies to create a natural balance at this time of year. With the sun as warm as it is at the moment the pond water needs as much help as possible to keep cool and hence free from algae and greenwater.
This proportion of cover is the same whether you have a 5mx5m wildlife pond or a 60cm container pond.
It is still possible to plant your pond now as our plants are already rooted into their baskets and will just be ‘moving home’ not trying to establish from barerooted pieces at this time of the season.
In the case of waterlilies (Nymphaea):
1. Replace them in the same depth of water as they have been growing in at the Nursery so the leaves should be floating on the water surface and if necessary you should raise the basket off the pond base or shelf to achieve this during Summer but the basket should be lowered to below ice level before Winter. (This is not necessarily its maximum depth as indicated on the ticket – do not lower by more than 12″ or 30cm at one time.)
2. Also use a fertilizer tablet in each waterlily basket now so that the plant receives a boost and continues to flower for the rest of the summer.
3. If your existing waterlily leaves are standing upright rather than lying flat on the pond water they are telling you they are ready for splitting or pruning next Spring. They should be lying flat to give you maximum coverage across the water surface. Standing upright is not helping the coverage!
4. Take a photo now so that you remember which waterlily you need to work on in Spring. Don’t tackle all waterlilies in the same year – do one basket at a time as they will be knocked back a little the year you do them.
Other surface cover water plants could be free floating like the Hydrocharis morsus ranae (Frogbit) which floats in the water and puts small leaves (1″ wide) across the water surface – ideal for a container pond or Menyanthes trifoliata (Bog Bean) which rafts out across the larger pond from a basket placed on the pond shelf.