Making the Most of Perennials

SIMON SHAKESPEARE continues his sustainable approach to gardening with a look at ways of improving the health of your soil - and how to make the most of perennials.

THESE past few weeks have brought mixed feelings for me: the excitement of this new season - emerging out of the still of winter and into the explosion of spring - is often tinged with a feeling of urgency and a sense that, as the evenings grow longer, I am still behind schedule when it comes to this year's plantings.

But as I try hard to resist the urge to run faster just to catch up, there is something that brings a sense of balance, and I have noticed it more this year than in the past five years that I have lived where I do. It is the re-emergence of the perennial plantings that I have made over the past years. Without any work on my part, perennial salads have already made a welcome contribution to the lunch table, currants are already plumping up and look like cropping well this year, and the hard fruit blossoms (first Merryweather damsons, early and mid-season apples) hold the promise of another year's harvest. And all this with the absolute minimum of input from me.

In the last issue of Connect, we looked at the concept of greener gardening and how this involves, first and foremost, trying to create energy in the garden; secondly to conserve and only then to consume energy within the garden. The article looked at various ways in which this could be achieved, but concluded that it is most likely to come about through understanding and good design - after all, in greener gardening terms, A Garden is Nature Understood; not Nature Under Control.

So if we assume that applying the principles of greener gardening is going to be a lot easier if we work with Nature rather than working against Her, then developing a design that incorporates a framework of edible or otherwise useful perennials will enable us to create more sustainable gardens and thereby create or conserve more energy in the garden than is consumed. This does not mean having to rely on a diet of dandelion leaves all year round, but rather is about developing an infrastructure into which our annual plantings can fit.

One of the most important aspects of developing this 'perennial framework' is the level of ecological balance that can be achieved through increased soil fertility and good soil husbandry. The advantage of working with a predominantly perennial design is that, unlike more traditional gardening methods, you can easily address and positively influence those aspects of soil which are crucial to healthy growing. Not only that, but by combining this approach with the benefits of mulching, soil health is achieved in a much more organic and holistic manner.
Why might that be important?

Well, for example, most non-organically grown foods have done so through the liberal application of chemical growth promoters - usually "N,P,K" (Nitrogen, Phosphorous and Potassium, for leaves, roots and fruits, respectively). These are the 'bulking out' minerals that all plants require. However, without the less voluble but equally (or more!) important trace minerals, that perform a multitude of functions both within plants and within us when we ingest them, we ourselves ultimately suffer from their absence.

So planting perennials, using mulch techniques and keeping a watchful eye on soil health can help us to enjoy more balanced gardens, consume more nutritionally-packed food and save us a lot of work to boot! So what plants are we actually talking about?

We've already mentioned both soft and hard fruit which most gardeners will be familiar with. We could add to this list grapes and kiwis; a whole host of leafy greens (in fact most native, edible hedgerow or woodland greens) - and of course dandelions! See the 'edible perennials' list, below, for more details.

So the key to this approach is building a positive fertility spiral where increasingly healthy soil produces highly nutritious plants that can be harvested without destroying soil structure. Regular application of mulch (composted vegetable waste and excess growth matter) ensures there is no net reduction in the nutrient level of the soil.

Judicious selection of 'glade' areas ensures space for annual plantings. The outcome is a garden that requires less and less work to achieve increasing yields and become more sustainable. Which is where I like to think my garden is heading.

Edible perennials include all tree crops and bush fruit, as well as the following:
Welsh Onion (Allium fistulosum)
Shallot (Allium ascalonium)
Chives (Allium schoenoprasum)
Bamboo shoots (Arundaria fastuosa)
Asparagus (Asparagus officinale)
Land cress (Barbarea praecox)
Spinach beet (Beta vulgaris var vulgaris)
Perennial broccoli (Brassica oleracea botrytis asparagoides)
Cardoon (Cynara cardunculus)
Globe artichoke (Cynara scolymus)
Jerusalem artichoke (Helianthus tuberosus)
Lovage (Levisticum officinale)
Ice plant (Mesembryanthemum crystallinum)
Parsley (Petroselinum crispum spp)
Hamburg parsley (Petroselinum crispum spp tuberosum)
Rhubarb (Rheum rhabarbarum)
Sorrel (Rumex acetosa)
Dandelion (Taraxacum officinale)
New Zealand spinach (Tetragonia tetragonioides)