Your gardening questions answered: What’s wrong with my magnolia?

It may be a glory of spring, but the magnolia is also challenging to grow well

Q: I have a magnolia tree since 2018. There was a few flowers on it when I got it, but it hasn’t flowered since. It is also late to produce leaves every year – mid-May. What can I do to encourage flowers please? MM, Co Tipperary

A: These slow-growing flowering shrubs or small trees are one of the glories of spring and can be found growing in many of the country’s finest gardens. But as is almost always the case in gardening, a happy, healthy specimen is inevitably a result of the right plant in the right place, and they can be challenging to grow well. This is especially true in colder midland gardens, where their foliage and flowers are more vulnerable to late harsh spring frosts and cold winds that singe the emerging leaves and buds.

Along with a sheltered spot in full sun or light shade, most (but not all) types of magnolia also need a fertile, humus-rich, damp but free-draining, neutral or slightly acidic, soil to flourish.

I say not all, because Magnolia grandiflora and M. delavayi are among the few species that are more tolerant of a dry alkaline soil, while varieties of Magnolia sieboldii and Magnolia wilsonii will tolerate a damp alkaline soil. But most tolerant of an alkaline soil is the lovely star magnolia or Magnolia stellata, a compact, relatively resilient, deciduous species suitable for small gardens with large, white, starry flowers that appear on the plant’s bare stems in mid-spring.


Although it still appreciates a sheltered spot, its long lasting, graceful blooms are also more resistant to frost damage than those of the larger, tulip-flowered species of magnolia, making it a better choice for gardens in colder parts of the country. It can also be grown in a large pot or tub, unlike other popular, but much larger kinds, such as Magnolia x loebneri ‘Leonard Messel’ or Magnolia soulangeana, both of which form small trees.

In the case of your own magnolia, you don’t say what species you’re growing but my guess is that it’s one of the large, fussier, earlier-flowering kinds. To find out what’s wrong with it, I’d suggest that you start by evaluating its growing conditions to see if the reason that it’s struggling is that: (a) the soil is too alkaline; (b) the soil is too dry and is lacking in organic matter; (c) the soil is too wet; (d) the site is too cold or exposed; or (e) it’s in a spot that’s too shady.

Young plants can also often struggle to thrive in their early years until they establish a strong healthy root system. So it may also be the case that yours is just biding its time while it gets its feet properly in the ground. But if you do decide to transplant it to a more favourable position in your garden, then it’s important to do so in late autumn or early spring, choosing a time when the soil isn’t frozen or waterlogged. See what I mean about magnolias being challenging to grow well?

Fionnuala Fallon

Fionnuala Fallon

Fionnuala Fallon is an Irish Times contributor specialising in gardening