Start with a handful, not a harvest

The best displays on a British kitchen table are rarely the most ambitious ones. A handful of stems cut on a damp morning and dropped into a jug will usually beat a tightly wired bouquet, and it will look far more at home beside the teapot. So keep the picking small. Three stems, or five, or seven — enough to fill the neck of the jug without crowding — is a proper arrangement.

If you garden in pots, on a balcony or on a small patch behind the shed, this suits you especially well. Small gardens give you a little of everything: a few stems of this, a couple of those. That variety is exactly what the jug method is built for.

What is worth cutting this week

Cut what is genuinely in flower rather than waiting for the perfect specimen. Half-open buds last longer in water than fully open blooms, and they carry on opening on the table, which is half the pleasure. A rough guide to the British year:

• Spring: narcissi, wallflowers, tulips (cut when the bud has coloured but is still closed), forget-me-nots, pulmonaria, the first aquilegias.
• Early summer: alchemilla, sweet williams, roses, sweet peas, chives, hardy geraniums, the first peonies.
• High summer: cosmos, dahlias, scabious, cornflowers, calendula, nicotiana, crocosmia.
• Late summer into autumn: asters, sedum, hydrangea, Japanese anemones, seedheads, a few hips and berries if the birds can spare them.

Herbs count too. A sprig or two of mint, rosemary or fennel adds scent and a soft green line without costing you a flower bed.

The angled cut, and other small habits

Pick in the early morning or in the evening, when the plant is not under full sun. Take a clean, sharp pair of secateurs and cut the stem on a steep diagonal — roughly 45 degrees — which gives a larger surface for the stem to take up water. Have a bucket of cool water beside you and drop each stem straight in; a stem left lying on the path for twenty minutes will never quite recover.

Once you are indoors, strip every leaf that would sit below the waterline in the finished jug, plus a little more. Leaves under water rot within days and turn the water sour, which is what shortens most arrangements. Then leave the stems in cool water in a shady spot for an hour or two to condition before you arrange them. Milky-stemmed flowers such as poppies and hellebores benefit from having their cut ends dipped in hot water for a few seconds before conditioning.

Grouping colours loosely, not carefully

Now the arranging itself, which should take about three minutes. Choose a loose theme rather than a scheme: one main colour, one echo of it, and plenty of greenery. Clump similar colours together instead of dotting them about, because a block of three pink stems reads as a deliberate gesture while three scattered pinks read as an accident.

Cut the stems to roughly one and a half times the height of the jug — a tall jug takes taller stems, a squat one takes short ones. Build a rough criss-cross with the first few stems so they hold each other up, then add one at a time, turning the jug as you go. An odd number usually sits better than an even one. If the jug is wide, a piece of chicken wire pressed into the base, or a grid of tape across the rim, will hold the stems where you put them. Resist the urge to keep adjusting; two or three tweaks at the end is the whole job.

Small spaces, generous returns

You can grow cutting material almost anywhere. A 30cm pot of cosmos will give you stems from July to the first frosts if you keep picking. Dwarf dahlias do well in containers, sweet peas in a deep pot with an obelisk, nasturtiums tumbling over a balcony rail. Even a windowsill box of herbs earns its keep.

Cut-and-come-again annuals are the small-space gardener's best friend: the more you cut, the more they flower. Sow a few seeds every fortnight through spring rather than all at once, and you will have something for the jug from early summer right through to October. Grow them among the vegetables if space is tight — cornflowers and calendula will not mind sharing.

Making it last the week

Refresh the water every other day and re-trim the stems by a centimetre at the same time. Stand the jug somewhere cool and out of direct sun, and keep it away from the fruit bowl: ripening fruit gives off a gas that speeds up ageing in flowers. As individual blooms fade, pull them out, so that by the weekend you have a smaller, cleaner arrangement rather than a tired one. A jug that changes across a week is doing its job properly.