One of the worst faults I have as a gardener is not allowing plants sufficient space. I am too greedy, wanting to cram as many different plants as I can into a garden bed. I do find it very difficult to visualise the final dimensions of plants, most particularly their widths. In fact, till recent times I have pretty much paid no heed to how wide plants are said to get! As a result, my plants often struggle to fulfil their true potential.
For example, last week in the garden of a friend, I saw a specimen of Salvia 'Wendy's Wish' that was easily a metre wide. It looked fantastic and had such a presence. In contrast, my own poor 'Wendy' is squeezed between a robust Cuphea ignea 'Starfire Pink' and some vigorous Canna plants, and is barely 40 cm across. This foolish pattern is repeated all through my overcrowded garden.
Last winter, I did try to renovate a large border and remove some plants altogether, in order to give others more space to grow. In doing so, I found that many of my perennials and shrubs had been so swamped and overshadowed by others that they were almost dead. They struggled for survival and at best had a few straggly stems, and flowered very poorly. I found it extremely difficult to take plants out, but forced myself to be hard-hearted, so that in a space where I would once have had three or four plants, I left only one. The reward this summer has been seeing the plants that remained - such as Dahlia, Echinacea and Salvia - truly flourish. I certainly don't like to see too much space between plants in the height of the growing season, and prefer the plants to merge into each other, but they need to have sufficient space around them to develop their full stature, otherwise they will require constant trimming through the warmer months to keep them in their allotted spaces.
The same logic should be applied to planting out annuals. Though they look so forlorn and pathetic when first put in, if given enough space, they will become much sturdier, healthy plants. Self-sown annuals in my garden, such as Orlaya grandiflora, Browallia americana, Amaranthus caudatus (pictured left), Viola tricolor etc, need to be ruthlessly thinned so that the few survivors can develop properly - otherwise they will remain a sad thicket of starved, stunted seedlings. It seems so harsh but the strategy pays off. I pull up about a thousand Amaranthus seedlings each spring, leaving about four or so in situ; given the space, these develop the stature of small shrubs and are an integral part of my summer and autumn borders.
Some plants more than others need more than their fair share of space around them - especially those with a distinctive shape. I love ornamental grasses (mainly Miscanthus species and cultivars and Pennisetum setaceum 'Rubrum', pictured left) but to look their best, I think they shouldn't be at all hemmed in by other planting. I prefer to site them where their full fountain-like shape can be shown, with only low plantings around them. Other strappy plants such Phormium and Cordyline cultivars also need to be given their own space - I grow my Phormium in squares set in paving, with very low groundcovers around them. Growing these plants in large pots is another way to show them off as well as possible. Daylilies are another challenge to place so that their arching leaves aren't obliterated by robust neighbours; the sculptural forms of Agave, Colocasia and Alocasia also need to have elbow room around them.
Giving plants more physical space to develop also means they are not competing as intensively with other plants for moisture, nutrients and sunlight. They also have the benefit of good air circulation around them - a factor that I think is important, especially in this very hot and humid weather we are experiencing at the moment, which is conducive to many fungal diseases that can affect plants. It is very challenging to not overplant a new garden bed, but the payoff is healthier plants that truly flourish. I am really trying to put this philosophy into practice! This week I acquired a new, compact form of Alternanthera dentata sold as 'Little Ruby' (pictured above), with stunning burgundy foliage. It has smaller leaves and a more dense habit than the species plant, and according to its label, is said to grow just 30 cm tall - BUT up to 90 cm wide! Normally, I wouldn't have paid attention the latter information, but I am going to try hard to plant it where its lovely WIDE rounded form won't be lost. Wish me luck!
The charm of vintage gardening books
28 Feb 21
A trip back in time
21 Feb 21
Cane-stemmed Begonia cultivars are summer stars for foliage and flower power in Sydney gardens.
14 Feb 21
There are some unusual flowers on my grasses now.
07 Feb 21
These plants bloom for many months in my garden - and some are in flower all year!
31 Jan 21
Many scented flowers are in bloom now.