• Maureen Little

The Four Fs - Designing a Planting Plan

I was having a chat with a friend the other day and she was asking how she should go about putting together a planting plan for the new border she had dug out. I did consider suggesting that she might like to sign up for a short course her local land-based college, or have a look at some online courses. But all she really wanted was a few pointers – she already knew roughly what plants she wanted that would suit the conditions; what she was lacking was how to put them together so that the border would look attractive, would ‘feel right’. So, having designed and planted many a border in my garden-designer-days, I put together a sort of crib-sheet for her.

And I thought, why not share it with everyone? So here is a slightly less-chatty version!

The Four Fs

A tried and tested method is to select plants according to their function, which you can generally split into four categories: Focus; Framework; Flowers; and Fillers.


This is the plant (usually a tree or large shrub) which acts as a focal point in the planting space. You need to choose a plant which is visually strong but does not overwhelm the space: in other words, it needs to be in proportion to the rest of the planting or the garden as a whole.

A Focus should command attention all year round – we still need something good to look at even during the winter months. If your planting area isn’t large enough to cope with an imposing Focus you can opt for a smaller specimen, or even choose a non-plant focus, like a sculpture or a bench.


These plants are usually shrubs, both evergreen and deciduous, which you can use to create a framework within the border. Like the Focus plant, Framework plants have to be in proportion to their plant neighbours. Imagine a bed of alpine plants with a solitary two-metre conifer growing out of the middle of it – not a pretty sight! Framework plants can also help to balance the scheme: this can be symmetrical, where you replicate the same plant; or asymmetrical where a large shrub at one end of a border may be balanced by a grouping of several smaller, evergreen perennials at the other. Framework plants can also lead your eye along the border, creating movement from one area to another.

Framework plants provide year-round structure, with interesting flowers, foliage, stems or berries at various times.


This group consists mainly of herbaceous perennials which come into their own during the late spring through summer to autumn months with their flowers providing a riot of colour, texture and form.

Flowers are perhaps the most hard-working when it comes to design: their attributes (like colour, texture and form) can be used in many different ways - subtly or boldly, traditionally or ingeniously, densely or sparingly – to create a satisfying design.

Strictly speaking herbaceous perennials are those plants which do not have woody stems; this category not only encompasses those plants which die down each autumn to reappear the following spring, but also tends to include perennials with evergreen foliage, some herbs, and, occasionally, alpines and bulbs. I also include some plants which are strictly shrubs or sub-shrubs, like Lavandula or Perovskia in this category – I tend to use these as I would a herbaceous perennial.

The way in which Flowers are used can affect the ‘feel’ of the design from dramatic to hotch-potch. Blocks or drifts of the same plant can look stunning (and are brilliant for bees, by the way) but you need a bit of courage to put this into practice. At the other end of the planting spectrum is the collection of single plants which carry a meaningful association, or you’ve bought them simply because they looked good. From a design point of view, groups of three perennials or more work best.


Filler planting gives instant colour and drama exactly where it is needed - bulbs, annuals, self-seeding plants, biennials and some tender perennials fall into this category. You can sow or plant them where there is a gap or, alternatively, you can grow them in pots and then plant them where there is a space. By filling in the gaps, these plants can provide an immediate, albeit transitory, focal point or create movement through a border, and they are past masters at repetition.

How the ‘Four Fs’ fit together

In order to give you some idea of how this method fits together in a plan without worrying about specific plants, I have put together a border in a simple diagrammatic form. Here we have a Focus, balanced by three Framework ‘plants’, with Flowers making up the bulk of the space, and some Fillers in between. By paring the forms down to basic shapes we can see how each of the categories fits in to the overall scheme.

Maturity of plants

Another point to remember is the mature height and spread of each plant. This will affect the number of plants that you can comfortably fit into a planting space.

Trees and shrubs will obviously take longer to achieve maturity (some of them will take many years) whereas many of the perennials will start to become overcrowded or deteriorate after three or four years or so, at which time you can dig them up and divide them. Some perennials are even shorter-lived and may need to be replaced after two years.

By contrast the bulk of ‘Filler’ plants will be at their best in the same year that you plant them.

Bear these points in mind when you plant up your new border and don’t worry if you have bare ground in places – the Flowers will grow into the spaces and meanwhile, that is what your Fillers are for.


The last point to consider is seasonality. Unless you particularly want a spring- or any other season specific-border, try and include plants that will have points of interest at various times during the year. And don’t think of just colour as a point of interest – things like texture and form can also be interesting!

A Real Planting Plan

In true 'Blue Peter' fashion here’s a design I made earlier so you can see how it all hangs together!

This Cottage Garden plan is for an ‘island’ bed, measuring some 5 metres by 5.5 metres – an added bonus is that it is bee-friendly too!

Key to Cottage Garden Island Bed


At the heart of the plot (A) is an apple, Malus ‘Rev W Wilks’ trained as a goblet. (The picture shows a pear, but the principle is the same.)

This variety is ideal for such manipulation and, being self-fertile, will produce a good crop in the absence of another tree for pollination, although there will be a more uniform crop if there is one close by.


The main Framework in this garden is provided by the low outline hedge of roughly 150 Buxus sempervirens ‘Suffruticosa’. This is the compact, very dense form with small leaves, ideal for as an edging plant. Because of the ravages of box blight, you may want to substitute this with something like Teucrium: it can get a bit straggly, but it responds well to being clipped, and if you do delay any clipping and allow it to flower, the bees will thank you for it.


This is really a garden of Flowers, with lots of ‘old fashioned’ plants like Lavandula, Aster, Hylotelephium and Geranium which between them provide colour for us and food for bees throughout the season.

1. Nepeta hybrida ‘Pink Candy’ x 3

2. Lavandula angustifolia ‘Hidcote’x 3

3. Eryngium x tripartitum ‘Jade Frost’ x 3

4. Digitalis purpurea ‘Pam’s Choice’ x 3

5. Pulmonaria ‘Cotton Cool’ x 3

6. Hylotelephium ‘Strawberries and Cream’ x 3

7. Geranium pratense var. striatum ‘Splish Splash’ x 3

8. Echinacea purpurea x 3

9. Polemonium caeruleum x 3

10. Aster x frikartii ‘Mönch’ x 3

11. Verbascum ‘Cherry Helen’ x 3

12. Salvia rosmarinus x 3

13. Salvia officinalis Purpurascens Group x 3 with Satureja montana x 5

14. Hyssopus officinalis (pink variety) x 3 with Origanum vulgare x 5

15. Hyssopus officinalis (blue variety) x 3 with Origanum vulgare x 5

16. Salvia officinalis x 3 with Satureja Montana x 5


I have suggested planting thyme between the stepping-stones leading to the apple tree. The thyme will soften the edges of the stones and if you step on it rather than the stones you will be greeted by a spicy aroma as the leaves release their oil.

Crocus and Allium schoenoprasum (chives) are planted either side of the stones, whilst Allium, Tulipa, annual Papaver and Phacelia fill in the gaps in the main planting. If you allow the latter two to self-seed they will form a tapestry of unifying colour during the following years. Beware, however, that they can be prolific self-seeders and will take over the plot if you allow them to: a little judicious thinning out may be called for each spring.

C Allium schoenoprasum planted alongside stepping-stones x 24

H Thymus serpyllum planted between stepping-stones x 18

O Allium ‘Purple Sensation’ planted as infill in gaps x 20

P Phacelia tanacetifolia planted in gaps x 20

R Crocus chrysanthus ‘Cream Beauty’ x 40 and Crocus vernus ‘Remembrance’ x 40 planted alongside stepping-stones

T Tulipa ‘Purissima’ x 24 and Tulipa ‘Negrita’ x 24 planted in gaps

V Papaver somniferum planted in gaps x 20

So there we have it - the Four Fs in action!