Why layering gives you months of colour

The frustration with spring bulbs is that most of us plant them all at the same depth, so they flower in one glorious but short-lived burst and then the show is over. Layering — sometimes called lasagne planting — solves this neatly. The principle is simple: different bulbs naturally sit at different depths in the soil, so if you plant them in bands, one above the other, they emerge in sequence rather than all at once. A single generous pot can carry you from the first crocuses in early February right through to the last tulips in late May, with something new unfurling every fortnight.

Depth matters here for two reasons. Shallow-planted bulbs warm up sooner in spring and flower first, while deeply planted ones stay cooler and come later. That natural difference is exactly what you are exploiting. You also get a fuller display: three layers of bulbs in one pot means three times the flowers in the same patch of compost, which is a real bonus on a small patio.

Choosing bulbs for a continuous season

Start with the early risers and work forwards. Crocuses are the reliable opening act, with Crocus tommasinianus and the larger Dutch hybrids often showing colour in the first weeks of February. The little dwarf iris, Iris reticulata, follows close behind and brings a startling blue to grey late-winter days. Then come the narcissi, beginning with the early cultivars such as 'February Gold' and 'Rijnveld's Early Sensation', before the main daffodil season in March and April.

Tulips carry the display over the finish line. Early singles and the sturdy fosteriana types open in April, while the late-flowered varieties will still be going strong at the end of May. A useful outline for a layered pot:

• Layer one (top, shallowest): crocus and dwarf iris for February
• Layer two (middle): dwarf narcissi such as 'Tête-à-Tête' for March into April
• Layer three (deepest): tulips such as 'Purissima' or 'Queen of Night' for late April and May

If you want to stretch things further, add a few grape hyacinths or a handful of alliums for the gap between the tulips and early summer.

How to layer bulbs in a pot

Choose a container at least 35-40cm deep and wide enough to look generous. Depth is what buys you the layering, so resist the pretty shallow bowl. Make sure there are drainage holes, and cover them with broken crocks or a layer of grit to stop the compost silting up.

Use a peat-free multipurpose compost mixed with about a quarter grit by volume, which keeps it open and free-draining through a wet British winter. Then build upwards:

• Bottom layer: fill to roughly 20cm from the rim and set the tulips in, pointed end up, spaced about a bulb's width apart.
• Cover with 5cm of compost and firm it gently, then set the narcissi on top at around 12cm deep.
• Cover again and place the crocuses or iris at 5-8cm, closer together than the larger bulbs.
• Finish with a final 5cm of compost, leaving a watering gap below the rim.

Water them in once, then keep the pot somewhere cool and out of the wettest weather until shoots appear. Growth above ground is a sign the roots have formed and they are ready to take the full weather.

Layering in borders and grass

In open ground the same principle works, though you have more room to spread out. Plant in drifts of at least a dozen bulbs of one variety, because a formal row looks stiff and sparse while a natural drift looks deliberate. Tulips go deepest at 15-20cm, narcissi at 10-15cm, and crocuses at just 5-8cm. A long-handled bulb planter makes short work of it, and the lifted plug of soil can go straight back over the bulb.

Mark where you have planted with small labels or a scatter of twiggy prunings. This pays off twice: you avoid spearing a bulb with a fork later, and the twigs deter cats and foxes from scratching in freshly turned soil. Bulbs planted in a lawn — crocuses, snowdrops and the smaller narcissi work best — need their foliage left alone for six weeks after flowering, so keep the mower off that patch until late May.

Pests, squirrels and soggy compost

Squirrels are the great bulb thieves, and they seem to target freshly planted pots within days. A sheet of chicken wire laid over the compost and pegged down, removed once shoots are through, is the most reliable defence. A mulch of sharp grit over the surface helps too, and it sets off the emerging flowers nicely.

Waterlogging is the other common killer. Bulbs rot in cold, saturated compost, so never let a pot stand in a saucer of water over winter and raise containers onto pot feet to keep the drainage holes clear. If you garden on heavy clay, plant in raised beds or add grit generously to the planting hole.

Looking after the display afterwards

Deadhead as each flower fades, unless you want the seed heads, but leave the foliage completely alone until it has yellowed and collapsed on its own. That greenery is feeding next year's bulb, so cutting it back early costs you flowers. Once it has died down, a light feed with a high-potash tomato fertiliser helps the bulb fatten up for the following spring.

Daffodils and crocuses will happily naturalise and come back year after year in a border. Tulips are less willing, especially in heavy soil, and many gardeners treat them as annuals — lifting them after the foliage dies back, storing the bulbs somewhere cool and dry, and replanting in autumn. Either way, the reward for a couple of hours' planting in September is a pot or border that quietly gets on with flowering for four uninterrupted months.