It is immediately obvious to even the most casual observer let alone the serious and experienced gardener, that some plants do not sit comfortably with others. Perhaps they both have small leaves of a similar green colouring; in this case, you would find it difficult to see where one plant ends and another one begins. Similarly, if the flowers are of the same colour, or with only a very slight difference in hues, there will be a visual clash, with a mish-mash of textures and light, and the whole effect will be less than satisfactory.
So, how should we plan a planting scheme in and around the pond, which looks good from the moment we conceive it until the full realization of it in the garden?
Although the success of any planting combination is ultimately a matter of personal preference, it is generally accepted throughout the global gardening community that the best plant combinations are those in which, for example, large bold leaves (such as hostas, rodgersias or lysichitons) are sited next to finer-foliaged plants (such as astilbes, primulas or even irises. Similarly, because of the considerable difference between the shapes of the leaves, an attractive grass-like plant will sit very well next to a bold broad-leaved plant.
The colours of the leaves also plays an important role. For example, a plant with ‘normal’ green leaves can be enhanced by its being placed next to a plant with variegated leaves. Similarly, the variegated plant will stand out when surrounded by plants which have plain coloured leaves.
Placing blue-leaved plants, such as Hosta ‘Hadspen Blue’ or Festuca glauca ‘Elijah Blue’ next to, or in the vicinity of, yellow-leaved plants such as Hosta ‘Gold Edger’ or Carex elata ‘ Aurea’ can achieve a really pleasing combination.
One plant that tends always to be better placed on its own, as a specimen plant, is Houttuynia cordata ‘Chameleon’. It has so many colors and shades in its leaves that it does not really ‘go’ with any other plant. This should not, however, deter you from growing it, as it is beautiful in its own right.
Getting the Timing Right
One of the first points to be aware of when planning a border or a planting scheme is the periods when certain plants do certain things. It is usually the aim of the gardener to grow as wide a variety of plants as possible, and to achieve color and effect for as much of the year as possible. This will usually manifest itself in ‘pockets’ of color over a long season, rather than a carnival of color over a month or so, with nothing going on throughout the rest of the year.
Specifically, to grow a plant that flowers in early spring is perfectly acceptable, but to place it between two other plants that flower in early spring is perhaps a waste. There will already be a degree of color in that part of the pond or bog garden, so why not place this new subject somewhere else entirely, somewhere perhaps that is lacking color at that time?
The flowering time of neighboring plants is also critical if their colours are the same or similar. For example, a mid-summer flowering pink Astilbe next to a mid-summer flowering orange Hemerocallis would not be a good idea, as they both flower at the same time and the two colours clash. A mid-summer flowering pink Astilbe next to a late spring flowering orange Hemerocallis would be better, as the two plants will not be competing with each other for your attention.
Research your aquatic plants carefully before buying and installing them.
Use of the water and surroundings
Because we are concentrating on planting ponds, water features and bog gardens, we are not going to have the same problems of scale that are experienced in some other parts of the garden. It is not a good idea to site tall trees and large shrubs near to a pond, because they cast shade over the water, which prohibits good aquatic plant and animal development.
But at the planning stage, planting near to or in the water can have its own sets of problems. It is critical to know which plants need to have their roots in water, and which plants merely prefer moist soil at the planning stage. It is also important to know which plants will grow upright and which will hang over the pond edge or even drape into the water.
Waterlilies, for example, have virtually no above-water height, and so you can plant them anywhere in the pond and they will not spoil other plants. However, after a couple of years a vigorous waterlily can swamp other, less aggressive, varieties. Another point to bear in mind with waterlilies is that they do not like to be placed near fountains or waterfalls, as the constant water movement is debilitating to them.
One of the most attractive things about water is its ability to reflect. Reflection is a dimension unavailable in any other aspect of gardening, so we should exploit it. The reflection of plants growing in and around the pond can be enjoyed almost as much as the real above-water scene. A strategically placed garden ornament, birdbath, sundial or similar structure can also be repeated in a watery reflection. But beware, so too can ugly nearby buildings or, if you are not careful, even the neighbor’s washing line!