Getting it to bloom
Why won't my Magnolia grandiflora 'Gallissonnière' bloom? (and how to make it flower)
Also called Southern Magnolia, Gallissonniere Magnolia (Magnolia grandiflora 'Gallissonnière').
More about magnolia grandiflora 'gallissonnière'
About Magnolia grandiflora 'Gallissonnière'
Magnolia grandiflora 'Gallissonnière' · also called Southern Magnolia, Gallissonniere Magnolia · flowering
A vigorous, hardier selection of the evergreen Southern magnolia, 'Gallissonnière' bears glossy leathery leaves with rusty felted undersides and large, lemon-scented creamy-white flowers through summer into autumn. It tolerates colder, exposed sites better than the species and is often wall-trained in the UK. Slow to establish but long-lived and stately once settled.
Plant type: flowering
Watch for — Frost-damaged buds: Late frosts and cold winds can brown unopened buds and young foliage; a sheltered wall site and avoiding frost pockets reduces losses in cold UK areas.
The reasons magnolia grandiflora 'gallissonnière' isn't blooming
Almost every non-blooming magnolia grandiflora 'gallissonnière' traces back to one of these, roughly in order of how common they are:
- Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
- Too much nitrogen feed, driving lush foliage at the expense of flowers (very common with general or lawn feeds).
- The plant has not been deadheaded, so it stops flowering once it sets seed.
- Irregular watering — drought or waterlogging at the budding stage makes buds abort.
- It is still too young or was checked by a transplant and is rebuilding before flowering.
Feeding magnolia grandiflora 'gallissonnière' a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.
The fix — how to get magnolia grandiflora 'gallissonnière' to flower
- Maximise sun. Give magnolia grandiflora 'gallissonnière' the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers.
- Switch the feed. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
- Deadhead regularly. Remove spent flowers often to keep it producing more rather than stopping to set seed.
- Water consistently. Keep moisture even through budding and flowering — drought-then-flood swings make buds drop.
Light and feeding do most of the heavy lifting here. Dial in the spot with the light guide for magnolia grandiflora 'gallissonnière' and get the feeding right with the magnolia grandiflora 'gallissonnière' fertilising schedule — the wrong feed (too much nitrogen) is one of the most common silent reasons a healthy plant makes leaves instead of flowers.
Bloom season and what to expect
Magnolia grandiflora 'Gallissonnière' flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.
Post-bloom care so it flowers again
Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.
For everything else this plant needs day to day, see the full magnolia grandiflora 'gallissonnière' care brief and its watering schedule — a stressed, badly watered plant rarely has the energy to flower at all.
Magnolia grandiflora 'Gallissonnière' blooming — frequently asked questions
Why won't my magnolia grandiflora 'gallissonnière' flower?
Magnolia grandiflora 'Gallissonnière' blooms on the season's growth given enough sun, warmth and the right feed — there is no cold or photoperiod trick, just good growing conditions and a bloom-leaning feed. The most common reason it is not happening: Too little sun — most of these need full sun (or very bright light) to flower well; shade gives leaves, not blooms.
How do I make magnolia grandiflora 'gallissonnière' bloom?
Give magnolia grandiflora 'gallissonnière' the sunniest spot you have — for most bedding and fruiting plants, more direct light directly means more flowers. Move off high-nitrogen feeds and use a higher-potassium "bloom" or tomato-type feed as it comes into flower.
When does magnolia grandiflora 'gallissonnière' normally bloom?
Magnolia grandiflora 'Gallissonnière' flowers across its growing season (mostly summer) and, kept fed and deadheaded, can bloom for many weeks or right up to frost.
What should I do with magnolia grandiflora 'gallissonnière' after it flowers?
Deadhead, keep feeding lightly, and many will rebloom; collect seed from the best plants at the end of the season if you want to grow them again.
What is the single biggest mistake stopping magnolia grandiflora 'gallissonnière' flowering?
Feeding magnolia grandiflora 'gallissonnière' a high-nitrogen general feed and growing it in too little sun — you get a big leafy plant and almost no flowers.
Keep reading
- Magnolia grandiflora 'Gallissonnière' care — the full brief (light, water, humidity, problems, pet safety)
- Magnolia grandiflora 'Gallissonnière' light needs — usually the first thing to fix for flowers
- Magnolia grandiflora 'Gallissonnière' fertilising — the right feed for buds, not just leaves
- Should I water my plant? The simple check
- Why is my plant wilting? Wet vs dry
- Underwatered plant — signs and rehydration
- Why won't my peace lily bloom?
- Why won't my jade plant bloom?
- Why won't my tomato bloom?
- All 2023 bloom guides in the Growli library