A laburnum tree in full flower is a rare sight these days, but the burst of golden yellow flowers in late spring and early summer is truly glorious. It looks its best trained over a pergola or archway, to show off its pendulous pea-like flower clusters. It does, however, have a dark side, as the seeds that follow the blooms are highly toxic (it’s recommended not to plant laburnum near children’s play areas). Traditionally laburnums were planted in larger gardens, but there are newer varieties that will suit smaller gardens and containers.
Where to grow laburnums
In its natural habitat, Laburnum grows on scrubland and hillsides, so it prefers well-drained soil and full sun in the garden.
How to plant laburnums
As with most trees, plant Laburnum in autumn. After planting, mulch the soil well-rotted manure or garden compost, to aid fertility, and stake firmly.
How to propagate laburnums
Laburnums can be propagated by taking hardwood cuttings in late autumn and winter. You can also sow the seed in autumn.
Laburnums are relatively trouble-free, although can be prone to honey fungus. They may also suffer from black fly, leaf miners and powdery mildew.
How to care for laburnums
Laburnums flower on the new season’s growth, so prune between late summer and mid-winter. Free standing laburnums don’t need much pruning, other than standard maintenance for size, shape and health – remove any dead, diseased or crossing branches. However if you’re training your laburnum over an arch or pergola, you will need to trim and tie in the stems.
Great laburnum varieties to try
- Laburnum anagyroides ‘Yellow Rocket’ – a new introduction with a narrow, upright habit which makes it ideal for smaller gardens.
- Laburnum x watereri ‘Sunspire’ – a new variety, with medium height and a narrow habit, that would suit smaller gardens.
- Laburnum x watereri ‘Vossii’ – this is the best known variety, a cross between the two species laburnums. It’s a fast-growing tree with dark green leaves, and very long flower racemes. It has been given the prestigious RHS Award of Garden Merit.
- Laburnum alpinum ‘Pendulum’ – this is a weeping cultivar of the Scotch Laburnum. A smaller tree, it looks great as a stand-alone feature tree, and is a good choice for smaller gardens and containers.