Why Perennial Cut Flowers Are the Backbone of My Cutting Garden

I have always loved perennials, but like many cut flower growers, I started with annuals — bright, fast, and wildly rewarding.  Annuals are beautiful, don't get me wrong, I grow them aplenty, but wow they can be labour intensive, fickle and particular, even if the output is spectacular if you get it right.  Somewhere between juggling seed trays, succession plans, and the raising of three small children, I began craving a cutting garden that worked with me rather than against me. These days the true backbone of my cutting garden is herbaceous perennials. 

If you’re new to flower growing, here’s a quick clarification: perennials are plants that live for more then 2 years, biennials are in the middle with a two season lifecycle, culminating in flowering in their second season, and annuals complete their life cycle in one growing season.  Herbaceous perennials are non woody stemmed perennials that may die down or sometimes maintain some foliage over the winter - this is species and climate dependent. 

LOW input, HIGH output

What I really enjoy about perennials is the LOW input and HIGH output.  Perennials have  deep root systems, meaning they return year after year without needing to be replaced. This makes them a more cost effective and sustainable choice for my business, and really any gardener.  I run my small business with my three young children in tow, so the fact that they require less energy and maintenance then most annuals is a bonus for me.  They do require some maintenance of course, feeding, mulching, weeding, cutting back, dividing and supporting - but the painstaking start from seed and nurturing, weed pressure and preparation of soil, is not there every year.  Perennial maintenance is also less time sensitive — one week too long in trays can make or break an annual crop if you are not careful - and one family virus later and your whole succession is pants.

Payback — with interest

When it is time to propagate, you can do this in the winter by division of root crowns/ corms/bulbs.  This is so easy to do and in winter, unlike the mad rush of spring, I have the time to spare.  There is something extremely satisfying in winter dividing perennials, like winning a scratchy ticket; one, three year old plant turns into 10, which you tuck into the ground ready to pay you back in spring. So, even though they can be a little more tricky to start from seed, or an investment to purchase, the one off investment of time and money in perennials will pay off, and with care, will continue to bring you joy (and potential financial return), year after year. 

There are more perennials then annuals amoungst the flowers in these three bouquets. From the left they contain the following perennials; 1. Dahlia 'Peaches N' Cream', Physostegia virginianna 'Snow Queen', Campanula takesimana, Lilium 'Pink Tiger' and Scabiosa 'Fama White'. 2. Rhododendron maddenii, Rosa 'Sally Holmes', Vibuernum tinus 'Emerald Beauty' (woody perennial shrubs), Angelica pachycarpa, Veronica spicata 'Blue', Penstemon digitalis and Campanula persicifolia. 3. Campanula takesimana, Scabiosa 'Fama White', Asiatic lilies, and Digitalis mertonensis 'Strawberry Merton'.

Perennials have flex

I have also increased my ratio of perennials to annuals, due to their increased range of flexibility and environmental tolerance.  Perennial root systems tend to be deeper and more established,  making them more drought-tolerant once established and resilient to changing weather conditions. This year’s growing season has been one of the most unpredictable I’ve ever experienced, and in these changing times resilience is key.

Our section is east facing with heavy clay soil and plenty of shade, as well as being exposed to prevailing winds.  Many cut flower annuals have high sun and drainage requirements, so turning to perennials that prosper in a shady spot and can hack our heavy soil, has been somewhat of a revelation! Right plant, right place people!  

These are some of the tough perennials that have prospered on our section, with some shade and soil tolerance; Physostegia virginianna 'Rosea', Digitalis mertonensis 'Strawberry Merton'., Penstemon digitalis , Astrantia major 'Primadonna', Campanula takesimana and Polemonium caerulium.

A diverse bunch

The wide range of herbaceous perennials don't just have diversity in environmental preferences, but offer diversity through a wide range of flower shapes, sizes, and colors.  From the tall blue spikes of Delphinium hybrids to the succulent heads of Sedum spectabilie 'Autumn Joy'; from the  dainty white bells of Campanula persicifolia, 'Alba', to the bright orange ray flowers of Helenium autumnale ‘Waltraut’ . This variety of form and character allows us to create dynamic garden designs — and surprise surprise, they also give an amazing palette for flower design. 

Ilustrating the diversity in perennials of flower shapes, sizes, and colors are from the left; Helenium autumnale 'Waltraut', Sedum spectablile 'Autumn Joy', Pholox paniculata 'Little Boy', Astilbe arendsii hybrids, Campanula percisifiolia 'Alba', and Delphinum hybrids.

Environmental benefits

Looking at the bigger picture, there are also marked environmental benefits to growing perennials.  Because perennials don't need to be replanted annually, they help reduce soil disturbance. This supports soil health by maintaining structure and beneficial microorganisms.  The deep established root systems reduce the potential for erosion and encourage nutrient retention, and the yearly senescence contributes to organic matter. Additionally, many perennials attract pollinators such as bees and butterflies, supporting biodiversity and local ecosystems, even when the plants are not natives.

Extended flowering season

Annual plants often have short blooming periods (aside from some awesome cut and come again beauties like Cosmos, Zinnia and Dianthus) and a continual supply of blooms is insured by high maintenance and space hungry succession planting techniques. Many perennial plants bloom for several weeks or months, meaning continuous picking. I’m a huge fan of Scabiosa ‘Fama White’, which flowers for me from November right through to May — slow and steady, like a tortoise rather than a hare.  

Scabiosa caucasica 'Fama White'

Many determined perennials will also produce a second flush of flowers in autumn, if cut back after their original summer bloom, such as Phlox paniculata or Achillia millifolium cultivars.  You can also stagger perennial flowering times by strategically cutting back in late spring, delaying flowering on particular plants, with the bonus side effect of shorter sturdier plants, that produce more blooms and need less support. 

Different perennials have different flowering times naturally across a season, often triggered by changing day length, light levels or temperature. This means, by selecting a variety of perennials, with different bloom times and staggering their flowerings by pruning, an established perennial cut flower garden can provide an ongoing supply of varied blooms without need for succession planting.

Boltonia x asteroides a perennial cut flower garden plant

From the left; Achillia millifolium cultivars, Pholox paniculata 'White Admiral' respond well to a early season cut back to delay flowering or can produce a second flowering in Autumn. Autumn flowering daisies like the pictured Boltonia x asteroides naturally flush their blooms in early autumn.

Writing this blog post has only reinforced my conviction that perennial cut flowers provide a sustainable, low-maintenance backbone to any cutting garden. In addition to their practicality, I find joy in the rhythm of their return and improvement every year — the cycle of growth and senescence and renewal, of stored potential and quietly held future promise.