how to plant a bulb lasagne
To get dense and flowery spring pot displays, you have to try layering bulbs in what the Dutch call a bulb lasagne, layering them up one on top of another. The largest and latest flowering bulbs go in deepest, moving to the smallest and earliest in the top layer. The emergent shoots of the lower layer bulbs just bend around anything they hit sitting over their heads.
Done like this, you need to plant the bulbs slightly further apart than you would in a pot with a single layer so 1 to 11/2 inches apart is the right sort of spacing. The first layer can go as deep as 11-12 inches deep. Then cover them over with a couple of inches of potting compost, before you place the next layer of bulbs.
These combinations involve a two-layer lasagne, but you can push it to three, and branch out from just tulips to crocus, narcissus, or hyacinths. I’m experimenting with this triple-decker this year.
For the deepest layer, I’ve chosen the parrot tulip 'Orange Favourite' with huge, crinkly orange flowers, and the scent of freesias. It’s the last tulip to flower which is totally invaluable. In the middle I’ve chosen a mid-season bulb, good-old Tulip ‘Prinses Irene’ and I’m also trying out its newly bred sister, ‘Cairo’. This has the same silvery-green handsome leaves but is a deeper, richer colour. For one pot, my top layer is the famously reliable and handsome Narcissus ‘W.P. Milner’. The foliage appears in January in a sheltered spot and it can flower from February until April if you keep deadheading.
I’ve got another pot with the deliciously scented and delicate, March-flowering Narcissus ‘Minnow’ so I can compare which works best.
In my large Long Toms, (16 inches wide and 25 inches deep) I have fifteen bulbs in each layer, so forty five bulbs in the triple-decker. The bottom layer planted at nearly a foot, the middle at 8 inches deep, and the top bulbs 4-5 inches below the compost’s surface.
As well as one variety flowering at once, I’ve also been experimenting with mixing synchronised flowerers. I’ve had ‘Prinses Irene’ in my Long Toms mixed up with another couple of early varieties - Tulip ‘Havran’ and ‘Couleur Cardinal’. The colours of the three work wonderfully together – I call it my Venetian Tulip Collection - black, deep red and burnt orange, all at their best at the same time.
Last spring, I tried another trio of current favourites ‘Bruine Wimpel’, with ‘Jan Reus’ and ‘Helmar’. Tulip ‘Bruine Wimpel’ is incredible, the inside of its petals the colour of a brandy snap, the outside a mix of copper, chalk and pink, which looked magnificent planted with the deep wine-red ‘Jan Reus’ and a zing of boldness from the deep-red, flashed yellow ‘Helmar’.
This was a rival to my Venetian group, looking fantastic with bright, healthy, springy foliage through March, topped with flowers for April into May. ‘Havran’ and ‘Jan Reus’ are both the tallest of their groups, so they go in the deepest. Then comes ‘Prinses Irene’ , ‘Bruine Wimpel’, ‘Couleur Cardinal’ and ‘Helmar’ all about the same height, so it doesn’t matter which goes in which layer.
Large pot or smaller containers, in a group, or just one on its own, autumn is the time to plot, plan, and plant your spring-flowering bulb fiesta.