As gardeners rush to get bulbs in the ground and containers for flowers next spring, there's one approach well worth trying right now: The lasagna method. The basic idea is to plant bulbs with different bloom times at varying depths in a pot, so you have a succession of flowers throughout spring.
"It gives maximum impact from minimal space—in pots—because you can stack the bulbs deep, in layers," says garden designer, nursery owner, and bulb expert Sarah Raven. Here's Raven's step-by-step guide for using the lasagna method and her favorite combos for a spring full of color.
Sarah Raven is a U.K.-based garden designer, author, and owner of mail-order nursery sarahraven.com. Her latest book is titled A Year Full of Pots.
Lasagna Planting Step-by-Step
Planting using the lasagna method is nearly as simple as potting up any other bulb. The key is to plant the right bulbs at the right depths.
1. Gather materials: Choose three bulb types from large to small that bloom at different times in the season. Select a large pot with drainage holes, filling it with high-quality potting soil.
2. Plant: Place several of the larger bulbs—like alliums, tulips, or daffodils—at a depth of around 12 inches. Alternating a layer of soil with bulbs, plant the second-largest bulbs in the middle at around 8 inches, and the smallest bulbs (like anemones, crocus, or iris) 4 inches deep. At each layer, bulbs should be spread about 1 inch apart. Water well.
3. Overwinter: Fall-planted bulbs need 2–3 weeks of consistent 50°F–60°F temperatures to set enough roots. In USDA Hardiness Zones 3–5, store potted bulbs in an unheated garage or shed, where temperatures remain cold, watering once a month so they don’t dry out. In Zones 6–8, place potted bulbs outside in a shady spot. Keeping them in the shade helps prevent the plants from starting to emerge early if there’s a sunny spell midwinter.
4. Protect: To prevent squirrels or rodents from digging up bulbs outside, you can firmly attach chicken wire over the top of the pot or try Raven's method: Sprinkle chili powder and chili flakes over the soil, followed by a layer of spiky twigs and branches (like thorny rose prunings).
Related
Top Bulb Combos for Layered Planting
Raven is famous for her elegant bulb containers. Here are some of the combinations she plants year after year.
Jonathan Buckley. From A YEAR FULL OF POTS: CONTAINER FLOWERS FOR ALL SEASONS by Sarah Raven, from Bloomsbury Publishing
Fragrant
"I adore scented tulips so any mixes including ‘Ballerina’ are winners," says Raven. Her current favorite lasagna combination, above: ‘Ballerina’ with the bright pink ‘Mariette’ and the crimson ’Sarah Raven’ tulip (which was just awarded a prize from the Royal Horticultural Society).
Monochromatic
Raven loves to stick to a simple, serene palette by combining a variety of white tulips with different bloom times. In a window box, she likes to combines ‘Ice Stick’ and ‘White Valley’ with ’Starlight Sensation’ daffodils. It's a combo that delivers "whole-spring flowering, scent, and calm glamour," says Raven.
Richly Colorful
For a bolder palette, try tulips in shades of orange, deep red, and dark purple. Raven opts for bulbs in these hues from her own Venetian tulip collection— ‘Prinses Irene’, ‘Couleur Cardinal’, and ‘Havran’. "I’ve grown this combo every year for nearly 20 years now and still love it," says Raven. "I’d tuck Iris reticulata ‘George’ or similar in the top to give February flowers and color as a bonus."