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How to layer bulbs in pots as a bulb lasagne for a succession of beautiful spring flowers from February to June. It involves layering potting mix and spring bulbs in containers to set on your balcony, patio, porch, or just outside your front door. This fantastic autumn gardening project will set your garden up for spring color and cheer!
For me, the first of the year’s flowers always emerge from planters next to the door or kitchen window. They never fail to put a smile on my face because they remind me that even though the days are still dark and cold, warmer days are on the way. Dainty white snowdrops are usually the first to appear, followed by crocus, daffodils, and tulips. I love them all. I also plant many of these flowers together so that they bloom in the same pots.
Though you may have plans to plant bulbs in your flower beds and lawn, it’s well worth planting some in containers, too. They’re incredibly cheerful and add a splash of early color best enjoyed from the view out a window or doorway. Though you can plant containers with just a single type of bulb, the show ends after one blooming. For continuous color from early to late spring, you can instead plant a bulb lasagne. All it takes is a few types of flower bulbs, planting materials, and about half an hour of your time.
Lasagne Planting for Continuous Spring Blooms
The goal behind planting a bulb lasagne is to have flowers blooming throughout spring. The earliest bloom time could be snowdrops, and it could end with a burst of Dutch irises or allium flowers in late May to June. You accomplish this by planting bulbs that flower at different times and are planted at different depths in a single planter. When lasagna planting, smaller bulbs generally get planted more shallowly than bigger ones, and as they grow, they gently push past one another on the way up to bloom.
In planters, bulbs can be crowded in and layered to create displays that are more impressive than the ones in the garden. The technique of creating a bulb lasagne is similar to making the pasta dish. Instead of lasagne sheets, cheese, and sauce, as your ingredients, you instead layer potting mix and bulbs. You can get many more flowers in a small space this way and create beautiful, low-maintenance displays from late winter to late spring.
Most bulb lasagnes have two to three layers of bulbs, but you could have more if you’re using a larger pot. The video demo below shares how I’ve planted four layers of bulbs. It includes crocus, two types of iris, grape hyacinth, daffodil, and tulip bulbs. I chose the bulbs to give the longest flowering period possible, but you could keep yours much simpler. Planting just two types of bulbs can create a two-layer bulb lasagne. For example, a layer of narcissi and a layer of anemones (technically a rhizome) would give a burst of color in early spring and late.
Planning a Bulb Lasagne
The most important part of planning a bulb lasagne is to choose bulbs that can be planted at different depths. If you can plant a thick layer of tulips about six inches deep and a moderately thick layer of muscari four inches deep, it means you get many more bulbs in a single container! The larger bulbs get planted towards the bottom, while the smallest bulbs tend to be planted nearer the top. As they grow, the shoots move around the plants above and find a way to the surface.
The second most important part of creating a bulb lasagne lies in choosing bulbs that will bloom at different times. For example, snowdrops for an early burst of blooms that then fade away to be replaced by crocuses, daffodils, and tulips. It’s like a conveyor belt of spring flowers.
You can push this idea even further by planning for different flowers to bloom at the same time as each other. For example, crocus with iris reticulata or grape hyacinth with daffodils. I’ve also had daffodils and early tulips blooming at the same time, as well as hyacinths and tulips. When planning for flowers to bloom at the same time, think about the colors and the height of the plants and flower stems. If you pair plants that don’t crowd one another and who look good coupled up, then you’re on to a winner.
How Many Bulbs to Use
You can use a lot of bulbs when planting a bulb lasagne, but how many exactly depends on how large and deep your container is. It also depends on the variety of flower bulbs you choose. Some bulbs can be planted at two inches deep, others at three, four, five, or six inches, or even deeper.
You can create as many layers of bulbs as your container allows you to, providing that you space the bulbs out to allow the lower ones to push through. The deepest layer of bulbs can even be planted so densely that they are right next to one another but not touching. The ones above should be spaced out at least an inch to allow the lower plants to grow through.
Sourcing Flower Bulbs
Flower bulbs aren’t difficult to find and are readily available through nurseries, online retailers, and even supermarkets in early to late autumn. You can also order through a specialized bulb distributor for higher quality bulbs, bulk bulbs, and a wider range of types, colors, and shapes.
Though I buy a lot of bulbs from the local garden center, my favorite company for bulbs in Britain is Sarah Raven. In the United States, you may want to try Nature’s Hill Nursery and other small nurseries. The Skagit Valley is where tulips are grown commercially in the US, and you can get bulbs directly from farms such as Roozengaarde. For the best bulbs in the UK and Europe, try to order Dutch bulbs directly. Here are my picks for types of bulbs to plant in your bulb lasagne.
- Dwarf iris (Iris reticulata)
- Dutch iris (Iris × hollandica)
- Grape hyacinth (muscari)
- Daffodil (Narcissus)
What You’ll Need for a Bulb Lasagne
You’ll need a few materials to create a bulb lasagne, including bulbs, a container, potting medium, and mulch. After you have them assembled, it’s then a matter of layering them so that the bulbs have enough space to grow. Here’s your materials checklist:
- Flower bulbs, ideally that will bloom at different times
- A container that is at least 12″ in diameter and 9″ deep. Terracotta is best since it can breathe and ensure that it has drainage holes at the bottom.
- Alpine gravel as a mulch
- Enough free-draining potting mix to fill the container
- Crocks (optional)
Potting Mix for Bulbs
The important thing about the potting mix you plant bulb containers with is that it’s fertile and free-draining yet can absorb moisture. This generally means that we don’t use soil but a lightweight potting mix made up of fibrous materials that create lots of air pockets. Though optional, you may also want to mix in bulb fertilizer to help the bulbs grow healthily. With so many bulbs in one pot, it can help them to grow strong and beautiful.
To add even more drainage, I usually work in a good amount of perlite (maybe 20-25% of the mix), vermiculite, or grit (tiny stones), depending on what I have. I prefer vermiculite because it acts like little rocky sponges for moisture but doesn’t wet the potting mix. In containers, soil loses nutrients quickly, dries out, and can become rock hard. For this reason, you won’t see experienced gardeners use soil in pots and containers.
Add Potting Mix to the Container
For larger planters, I recommend that you move it to its permanent (or overwintering) position before you begin. That’s because containers can get very heavy once you begin filling them. If you’re ready with your materials and bulbs, you can start by filling the bottom of the pot with at least two to three inches of potting mix. It depends, though, on how deep the bottom layer of bulbs needs to go! If your deepest bulbs go five inches below the surface, measure that distance down and then another inch. That extra inch represents the extra amount of space from the top of the container to where the surface of the potting mix is. You don’t fill containers all the way up to the top with potting mix.
Plant the Deepest Bulbs
Next, lay out the first layer of bulbs. These will be the ones that need the deepest planting space, and the bulb packaging should tell you just how deep they should be. These bulbs are usually relatively large. Space them out so no bulbs are touching, but set them out as thickly as possible for a big display. Remember that the pointy ends of the bulbs are the tops and need to point upward. Sometimes, bulbs will already be sprouting, and that will let you know how to place them.
After they’re laid out, cover the bulbs with another layer of potting mix. At the bare minimum, it should just cover the tops of the bulbs, but how deep this layer is depends on how deep the next layer of bulbs should be. Get your measuring tape out again and refer to the planting instructions for your bulbs. If you’re unsure, plant them a little deeper than you originally thought. Bulbs that are planted a little deep have to work a little harder to get up in spring, but it’s usually no problem.
Plant More Layers of Bulbs
Next, layer bulbs that need less planting depth in a middle layer, and try to space them out so that they don’t sit directly on top of the bulbs below. They should ideally be about an inch apart, but a little more space is good, too. When the second layer of bulbs is spaced out, cover them with another layer of potting mix. Add a third layer of bulbs on top of that, trying to space the bulbs out about an inch or more apart from one another. Cover these bulbs with more potting mix. You could even add a fourth layer if you’d like, and your pot is deep enough.
Finish the Bulb Lasagne
Once you’ve planted all the bulbs, fill the container with potting mix to about one inch below the top edge of the container. Gently press it down with your hands to firm the potting mix down. Though I’ve seen other people recommend planting winter bedding plants such as pansies and violas on the top for temporary interest, I don’t do this. That’s because I tend to see the bulbs’ leaves begin pushing through as early as January. Bedding plants could hinder their growth.
The last thing that I recommend you do is finish the top of the container with a fine layer of gravel or horticultural grit about 1/4″ to 1/2″ in depth. This last layer serves several purposes: it keeps the container from drying out in spring, helps keep the potting mix from eroding, and stops weeds from taking root. It also looks nice! The bulbs below will be able to push their way through without any issue at all.
Overwintering Bulb Lasagnes
I live in a place that gets cold but doesn’t tend to dip much below freezing in winter. That means that I can set my bulb lasagne planters out in their permanent position and leave them there until spring. Winter rains keep the potting mix moist, and the bulbs start sprouting in January, with some flowers even blooming by the end of that month.
If your winters are colder, not only will your flowering times be later, but you may want to consider overwintering your containers undercover. An unheated garage, shed, or greenhouse can all give the bulbs enough protection until it’s warm enough to bring them outside. Keep in mind that bulbs in containers are more exposed to the cold than bulbs planted in the ground. Tulips are especially susceptible to freezing temperatures and may not survive in containers if they dip below 30°F (-1.1C).
Lastly, bulb rot is a real worry in winter. It happens when bulbs sit in waterlogged soil or potting mix, so it’s best to take precautions. Free draining potting mix helps move water out of the container, as does setting the pot up off the ground with pot feet or bricks in winter. It’s a good idea to do this for all of your terracotta pots to stop them from freezing and cracking during cold periods.
Bulb Lasagne Aftercare
Now, the waiting game. Your container will look unexciting for the autumn and winter months unless you also plant the tops with winter bedding plants. Then, all of a sudden, you’ll begin to see perky green leaves pushing through the alpine gravel, and before you know it, you’ll see the first blooms! It doesn’t take as long as you’d think since it’s easy to get distracted by the holidays.
During the time that your plants are growing, keep the container in a sunny spot and the potting mix moist. The best way to gauge when you should water is by getting your fingers in the potting mix to feel it. If it seems dry, water it – which may mean watering it every day as spring rolls on. It’s also well worth watering the container with a water-soluble feed for flowering plants on a weekly basis.
A big question that a lot of people ask is, what do you do with the foliage and flowers once certain bulbs have finished flowering? They can look quite scruffy and get in the way of other plants. The answer depends on your perspective. Some people treat bulb lasagnes as an annual show and aren’t concerned about the bulbs flowering again. In this case, you can remove all the foliage, stems, and spent flowers to make way for the next wave of flowers. This will severely weaken the bulbs, though.
If you want the bulbs to flower again next year, leave the green leaves to charge up with sun energy. You can remove them once they begin yellowing or loosely weave them together and away from fresher green growth but leave them on and in the sun for as long as possible. Your weekly feeds will also help those bulbs to bulk up for future displays.
Bulb lasagnes are something that many choose to replace every year, especially in containers. The first reason is that the potting mix can become depleted of essential nutrients. Secondly, because in many places, tulip bulbs don’t flower as well in their second year. It has to do with achieving their ideal winter temperature rather than anything else.
In Britain, where I live, most tulips will give a weaker second-year display, and then only a small percentage of them will continue to bloom in years afterward. There’s not much we can do about that aside from growing tulips bred to be “perennial.” All tulips are technically perennial, but some are bred to bloom consistently for years, even in places with slightly warmer winter temperatures than tulips prefer.
What I tend to do is set bulb lasagnes someplace out of sight over the summer, then bring them out again for a second display in spring. After that, the tulips in the planting will put up less of a show, and the other bulbs may become congested. Each bulb produces offsets (babies), and an overcrowded container often leads to less and less consistent blooms. After a second display, I’ll deconstruct the container the following autumn and plant the bulbs out in the garden. Then I’ll plant new bulb lasagnes!
More Flower Growing Inspiration
If you have any questions regarding planting bulb lasagnes, leave me a comment below. Here’s even more flower garden inspiration for you to discover: