Controlled randomness in the garden, a matter of style

There are times in the garden when there are beautiful successes as well as major failures; sometimes the failures stem from intense reflections: a scene between two plants that turns out disappointing, while conversely, there are stunning successes largely due to chance: two seemingly opposing colours that combine wonderfully. There is a third alternative, based on observation and plant knowledge: controlled chance.

A mix of Allium sikkimense, Elymus magellanicus, Hieracium villosum and Agapanthus, in a wild style.

Controlled chance involves using plants from the same medium and then staging them. In a sunny, well-drained spot, for example, one would naturally gravitate towards plants from open environments, such as meadow plants. Whether they originate from Europe, Central Asia, or North America, these plants from similar habitats share a common physiognomy. They often have an upright habit, foliage that offers minimal resistance to the air, and an anemogamous inflorescence, etc. When combined, these plants will create a meadow landscape, a natural scene shaped by human hands. To these plants, we can add structural plants with perfectly geometric inflorescences, such as a foxtail lily or ornamental onion, and the natural meadow will take on a more contemporary look. Alternatively, we can reduce the number of species to 3-4, contrasting two colours and three different forms to create a modern garden; this framework can be modified infinitely according to inspiration.

Using plants from the same habitats primarily ensures good rooting and excellent establishment; it may sound trivial, but a perennial in well-drained soil grown in heavy soil will struggle and eventually die.

So, when does controlled chance come into play? Let’s stick with our example of a well-drained, sunny garden and aim to create a white garden. First, let’s list the suitable plants: gaura, Chinese fountain grass, white lavenders, stipa, campanula, erigeron, eupatorium, hydrangea arborescens, valerian... These plants thrive under the same conditions and meet my colour criteria, BUT to achieve this famous controlled chance, I must consider a seemingly trivial parameter: the mode of propagation. Which plants have a wandering spirit that self-seed readily, and which ones have roots that hardly move an inch in ten years?

If I want to control my garden, I favour sedentary plants; however, this way, my bed will look the same year after year. If I want movement, I need to introduce a dose of chance and thus a dose of wandering plants. This is where controlled chance begins, as to maintain control, the proportion of wandering plants must be lower than that of sedentary ones; the right balance (at least in my rich, moist soil) is 4/5 sedentary and 1/5 wandering.

If I am observant, I know that hydrangea arborescens, Chinese fountain grass, white lavenders, and to a lesser extent campanula are quite well-behaved, so I will prioritise planting these varieties and will wait at least a year for them to settle in and gain strength. In my plantings, I will leave some large gaps, so that in 1 to 2 years, I can introduce wandering plants. This long period will allow the plants to establish well; they will be able to withstand the wandering plants and will be robust enough to limit the most adventurous ones. Thus, year after year, my landscape will change gradually and evolve each year without completely transforming; this is the concept of controlled chance.