How to create a spring bulb ‘lasagne’

If you haven’t yet ordered your spring bulbs, put that job on your radar because autumn is a perfect time to start planting for a blast of colour next year.

Planting two to three layers of different bulbs – depending on the depth of your pot and bulbs selected – to create a bulb ‘lasagne’ can make the colour last for months as a succession of bulbs bloom at different times, says gardening broadcaster, writer and teacher Sarah Raven .

“Bulb lasagnes create the most dense displays that bloom marvellously in succession over several months,” says Raven, whose latest book A Year Full Of Pots features many ideas for bulbs as well as other flowers.

“By staggering the flowering times of your bulbs, you can achieve a continuous display of abundant colour, with new blooms emerging as earlier ones fade. At Perch Hill (her East Sussex garden where she runs courses and events) we plant our bulb lasagnes in October, using either two or three layers depending on the pot’s depth and chosen bulbs.

“Use large pots for bulb lasagnes. I recommend ‘Long Toms’ that are 16 inches wide and 25 inches deep. If the bulbs get wet, the lasagne will fail, so cover the container’s drainage holes with broken crockery, pots, or gravel.”

Planting bulbs in autumn can also save money in the long-run, says Nigel Lawton, plant buyer for Dobbies Garden Centres .

“It’s a great value way to fill containers and beds with colour, as buying bulbs and planting now is more cost effective than buying mature plants for instant colour next spring.”

Spacing is slightly different in pots. Plant the bulbs slightly further apart than you would if you were planting them in a single layer, but closer together than if you were planting in a border – about 2-3cm (1 inch) is the right sort of spacing, so you can position your bulbs closer together than you would in the ground, Raven advises.

Don’t worry that your bottom layer of bulbs won’t be able to grow up through the layer of bulbs above because they will just grow around anything in their way.

Be prepared

“Preparation is key when it comes to planting in autumn,” says Lawton. “Fill your container around three quarters full with a good quality peat-free bulb fibre compost, and if you’re planting in the ground, loosen the soil to about 12 inches deep and add in your compost to provide a nutrient boost.”

Layer your bulbs

“When it comes to lasagne planting, you should always place the largest, latest flowering bulbs in the deepest layer of your pot or bed, moving to the smallest and earliest flowering as you get to the top. If you’re unsure about when your bulbs will flower, check the packet for instructions and organise by size and blooming time,” says Lawton.

Raven advises that the deepest layer of bulbs should be around 11-12 inches deep,  that they shouldn’t be touching and they shouldn’t touch the side of the pot.

Add a few inches of compost before planting the next layer around 8in deep and the top layer a few inches below the soil’s surface.

For the deepest layers, try parrot tulips such as ‘Orange Favourite’ before moving to mid-season bulbs like ‘Prinses Irene’ and ‘Cairo’. Narcissus is a reliable and deliciously scented option for the top layer, such as the handsome ‘W.P. Milner’ and delicate ‘Minnow’, she suggests.

“If you’re looking to bring instant colour to your pot or bed while waiting for your bulbs to grow, you can add bedding flowers such as pansies or primroses on top of your display,” Lawton adds.

Ideal recipes

“My perfect recipe for a bulb lasagne would be tulips, narcissi and crocuses,” says Raven. “Tulips are the ideal base layer and will complete the container’s cheery colour scheme. For the central layer, narcissi are perfect as they come into flower mid-spring.

“Muscari (grape hyacinth) is another stunning option. Crocuses are one of the first flowers to bloom in spring, making them the perfect bulb for the lasagne’s top layer.”

Lawton suggests a lasagne combination including Crocus ‘Blue Ocean’ (top), Narcissus ‘Twinkling Yellow’ and ‘Filly’ (middle), and Tulip ‘Pinocchio’ and ‘Sunlover’ (bottom).

Protect your bulbs

To ensure your bulb lasagne lasts throughout winter, continue to water your display once planted and ensure the compost is kept damp, but not wet, Lawton advises. Place your container in a shaded spot and when green shoots appear, move it to a sunny spot in your garden.

“To protect bulbs from frost over the winter months, mulch well with a peat-free bulb fibre compost, and if temperatures are expected to drop, cover with frost fleece. Add a dusting of bonemeal to feed over the coming months,” he says.