Sickly Magnolia Grandiflora
Caliope
Posts: 6
We rescued a VERY pot bound 10/12ft Magnolia Grandiflora about 3 years ago. It was extremely sickly looking, yellow leaves and only a handful of leaves on the end of each branch. It did have 2 flowers last year that lasted about a couple of days and the leaves are now beginning to look a bit brighter (watered with Epsom salts last summer) but it still only has about 5'ish leaves at the end of each branch and none further along the branch. I have left it alone for 3yrs to let it settle but am now tempted to give it a prune to see if that sorts it out. Would love advice on this please as I don't want to kill it but going into its 4th year in the garden it isn't looking much happier. I am on clay soil if that helps explain anything...
Thank you
Posts
I think it might be a good idea to post a photo of this plant. 10/12 ft is quite a huge size in a pot. Being pot bound and at that size is a worry. They may find it very difficult to settle into the ground at that size too. Usually, it's not advisable to prune these plants down hard, but I suspect the top growth is also causing the plant to stress due to the early problems in the pot.
Without seeing the shrub/tree, I think, being on the safe side, you can prune it down by a third to start off with and wait to see how it goes throughout the year. Mulch the base with loads of good compost/manure and try to loosen some of the soil around first. The Grandifloras are far more tolerant of alkaline soils, but they do need a good thick mulch.
The plant position should ideally be protected close to some type of wall or fence to keep it away from harsh winds. They do not flower that reliably in this climate, so bear that in mind. They need very hot summers to start flowering.
Last edited: 31 January 2018 18:37:54
Thank you both for your advice and, as suggested, I have attached a photo below so you can see the plant and let me know what you think - sorry its come out rather tiny!
The plant could be too exposed as you suggest...however, it is definitely happier than when we bought it having been set free from its 15 year pot but it is the sparseness of leaves that worries me. Also there are some branches with no leaves and I have left them for a year or two but think I might chop them off, would you agree?
Thanks so much for your help.
I have attached another image from a different angle as this might help you view the plant better.
Thanks
Thanks for those photos. The shrub/tree needs feeding, but I think the biggest issue is you need to remove a bit more grass around the base. Considering it had a difficult start being root bound, the soil conditions needs to be prepared with much more care. Get hold of good compost or well rotted manure and lay it or work it into the top layer once you have cut away at least 2-3 feet of grass out.
The shape of the shrub/tree is quite nice and not at all what I thought it would be. I would be tempted to reduce the length on some lower branches and prune back any branches without leaves. Apart from that, leave it for another year.
I think the sparse growth is due to the exposed position. And it will likely slow the growth down. If you want to keep it in its orginal position, maybe think about growing some shrubs behind it. They need protection and warmth from a house wall or some type of barrier.
Great, thank you, really helpful - I will take your advice and see how it is in another year.
When you say "prune back branches without leaves" do you mean prune them right back to the trunk or just take say a third off?
Thanks
Hi Caliope, on looking at the picutres of your shrub, I can see it wants to go upwards. The newest and strongest growth is showing at the top. I think you need to shorten or even prune right back into the main trunk some of the older and weaker looking lower branches. It's entirely up to you. It's all about planning how you want your plant to look.
When I say shorten, look at the branches lower down and prune to just before you see a bud/swelling if not to the main trunk. Don't worry if you are not sure, you can just shorten them. Magnolias are best pruned lightly and then wait a year to see what happens. Due to the previous stress, I don't think it's wise to take too much out. I think you need to also concentrate on feeding and making a better base for it to grow from. But generally, you have done a good job so far.
Thank you and last question and then I will leave you in peace, should I wait until the last frost before I prune it? So do it late March / early April?
They do take a long while to recover from bad treatment. (Which is why it's best to get a bare-root maiden whip of a tree not a pot-grown mature one). Definitely give it some more food and TLC as described above. Remember they can be used as hedging so cutting back should produce more bushiness but I'd be inclined to leave it as long as you can stand it, so it can form a tree shape in the long run. Also I agree with Borderline's comment about starting by shaping it into a tree and pruning lower branches so it continues growing from the crown.
Caliope, it's best to prune now till early spring but not later. When you see a mild spell (which I don't think is this coming week), do the pruning. Good luck with it.