How to grow magnolias
With hundreds of varieties available, choosing which magnolia to grow is like having to choose your favourite child, writes Barbara Smith.
What do dinosaurs and magnolias have in common? They coexisted around 100 million years ago during the Cretaceous period. In fact, magnolias were among the first flowering plants to appear, before bees, and were pollinated by beetles.
The Magnoliaceae family has been through a lot – ice ages and continental drifts being some of the biggies – so it’s not surprising that they’re a scattered bunch.
However, in general, deciduous magnolias are from Asia and evergreen magnolias from America.
How to grow
When it comes to choosing a magnolia, there is a glorious spectrum of shapes, sizes and colours available. Always check their specs first as some are 10-metre-high monsters best suited to larger gardens. You also need to find out whether it’s upright in growth or spreading. If you only have a small section, your magnolia dreams needn’t be dashed as there is a range of smaller, upright cultivars (usually up to 2m high) available.
Magnolias like moisture-rich, freedraining soil. If your soil is not up to scratch, fill your planting hole with rich compost and add gypsum to clay soils, then add plenty of mulch around the tree to lock in moisture over summer. It is crucial to water them through their first spring as they’re leafing up. If the plant has not had any good rain for a week, tip a 10-litre bucket of water around the roots.
In the north of New Zealand, deciduous magnolias will flower from July until September, whereas in the south they will flower later. Evergreen magnolias flower from summer to autumn.
Magnolias don’t really like being pruned. If you must prune, do it only when the tree is young as large branches can struggle to heal from cuts.
Varieties
With more than 210 species in the family and countless hybrids available, there truly is a magnolia to suit everyone, and New Zealand has smashed it out of the park when it comes to the international magnoliabreeding scene. This is largely thanks to the work of some Taranaki plant breeders who have bred some starquality cultivars.
For starters, there’s stunning ‘‘Iolanthe’’, a hybrid of Magnolia campbellii bred by the late Felix Jury of Waitara, which has deep-pink and lavender cup-shaped flowers. Bestsuited to a larger garden, it will reach 8m high x 3.5m wide. Jury also bred ‘‘Vulcan’’ (5m high x 4m wide in 10 years) which for a while was considered the reddest magnolia in the world. For smaller sections, ‘‘Black Tulip’’, bred by Jury’s son Mark, grows 3.5m high x 3m wide and has purple-black goblet-shaped flowers.
Further down the road in Taranaki, Vance Hooper has also produced magnolias of note, including wine-red ‘‘Genie’’, an excellent, longflowering variety, which was named best new tree or shrub at an international plant fair in Germany in 2011 and vibrant purple Cleopatra, which took out the same award in