Why Layering Gives You Months of Colour

Most gardeners plant a handful of daffodils in October and then spend April wondering why the show is over in a fortnight. The trick to a spring that unfolds slowly, rather than exploding all at once, is to plant in layers. Also known as lasagne planting, this means stacking bulbs at different depths in the same pot or patch of border, with the earliest, smallest bulbs nearest the surface and the largest, latest-flowering ones buried deepest.

It works because bulbs respond to soil temperature and depth. Shallow-planted crocus warm up first and flower in February or early March. Daffodils sit lower and follow a few weeks later. Tulips, planted deepest, take longest to stir and carry you into May. One container, three or four waves of flowers, and no bare compost in between.

Choosing Bulbs That Follow On From Each Other

Success depends on picking varieties with genuinely different flowering times. Read the labels and think in terms of early, mid and late rather than simply choosing by colour.

• Earliest layer: Crocus tommasinianus, Crocus 'Cream Beauty' or dwarf Iris reticulata. These flower from late February and rarely top 10cm, so they need the shallowest planting.
• Early to mid layer: Narcissus 'Tête-à-Tête' and 'February Gold' for pots, or 'Ice Follies' for borders. Compact, reliable and blessedly ignored by most pests.
• Mid to late layer: Tulipa 'Purissima' and 'Apeldoorn' are stalwarts, while 'Queen of Night' adds near-black drama in early May. Species tulips such as Tulipa turkestanica are smaller but return year after year far more willingly than fancy hybrids.
• Late flourish: Alliums are technically late spring rather than spring bulbs, but a scattering of Allium sphaerocephalon at the deepest level extends the display into June.

Aim for roughly three times as many small bulbs as large ones. A pot that holds twenty crocus, ten daffodils and five tulips will look generously planted at every stage.

Planting a Layered Pot, Step by Step

Choose the biggest container you can live with. A 35–40cm diameter pot holds far more bulbs and dries out far less quickly than a titchy one, and the extra compost insulates the bulbs through hard frosts.

Start with a generous layer of drainage material, then fill with peat-free multipurpose compost mixed with a couple of handfuls of grit. Bulbs rot in waterlogged soil, so drainage matters more than richness.

• Settle the deepest bulbs first — tulips, planted about 20cm deep, roughly three times their own height. Space them a bulb's width apart and press them gently into the compost, pointed end up.
• Cover with 5–8cm of compost, then add the daffodil layer at around 12–15cm deep.
• Cover again, then place the crocus and iris at 5–8cm, just below the surface.
• Top off with compost to within 3cm of the rim, water lightly, and finish with a 2cm layer of horticultural grit.

The grit is not decorative. It keeps the necks of the bulbs dry, deters squirrels from digging, and suppresses weeds. If squirrels are bold in your area, lay a piece of chicken wire over the pot and weight it down until shoots appear.

Layering in Borders and Under Trees

The same principle works in open ground, though you need to be more relaxed about spacing. Dig a trench about 20cm deep, set out the tulips, backfill, then scatter daffodils at 12cm and crocus at 6cm across the same patch. It looks chaotic on paper and completely natural in March.

Layered planting is especially useful beneath deciduous shrubs and trees. The bulbs flower while the branches are still bare, catching light that will have vanished by midsummer, and the foliage dies back just as the shrub fills out and hides the yellowing leaves.

In heavy clay, plant on a 5cm cushion of grit and fork the base of the trench to break up any pan. Bulbs sitting in a puddle over winter simply disappear.

Timing, Watering and Aftercare

Plant from September to late November. Tulips can go in as late as December and often do better for it, as a late planting reduces the risk of them being caught by warm autumn weather and starting into growth too early. All spring bulbs need a decent spell of cold to flower well, which is why indoor-forced bulbs are treated differently from those left outside.

Water pots through dry spells in autumn and again when buds appear — a dry spring means short stems and small flowers. Feed with a liquid tomato feed every fortnight from the moment green shoots break through until the flowers fade.

Resist the urge to tidy up too soon. Leave the foliage for at least six weeks after flowering, cutting it only when it has yellowed and collapsed. Those leaves are feeding the bulb for next year. In pots, you can lift the whole rootball and tuck it behind a shed to die back out of sight, or simply overplant with summer bedding and let the bulbs hide beneath.

Do it once, and next spring you will have a display that starts in February and is still going strong when the first proper sunshine arrives.