How to revive Mandevilla losing leaves?

[Rosana1]

Hello Bunnings workshop!

I bought a red Mandevilla from you guys a while ago and replanted it in our back yard, in a bigger pot. The spot is half shade/half sun, gets a bit of wind, but I believe it is a good place for it to grow and climb.

Unfortunately, the weather hasn't been very summery here in Adelaide, so it had to cope with a lot of rain, wind and some cold days so far, but also some sunny warm ones, so I'm not sure what's going on. It has many, many flowers, but recently it's been losing so many leaves. They all go yellowish before falling.It has increased a lot lately and they follow so quickly. It is also looking a bit sad, at least some parts of it. There's new growth , so I was wondering if the loss of leaves is normal due to all the flowers or if it has to do with the way we re arranged its branches with new supports and wall climbing devices. I'm attaching photos to give you a better idea. I have a water measurer stick that helps me water it only when necessary, so I don't believe it's water related.

Please help, a beautiful important piece in our backyard, would hate to see it die...

Thank you,

Regards,

Rosana

 

[JacobZ]

Hi @Rosana1,

Your Mandevilla actually looks very healthy, and the leaf drop you are seeing appears to be quite minimal. Mandevillas often shed a few older leaves as part of their normal growth cycle, especially when they are putting energy into flowering. Because yours is producing many blooms and new shoots, it is completely expected that some of the older foliage will yellow and fall away. This is the plant’s natural way of reallocating energy and keeping itself in balance.

The recent weather in Adelaide may still have played a small role, but only in a mild way. Cool nights, wind, and the extra rain can cause a few leaves to yellow, but in a plant that is otherwise thriving, this is not a concern. Since you have already given it a good position with a mix of sun and shade, and you are attentive with watering, the plant is clearly coping well overall. The fact that new growth is appearing strongly suggests that the Mandevilla is happy and establishing itself nicely in its new pot and support system.

Rearranging the vines and adding climbing supports can sometimes lead to a small amount of leaf loss, simply because the plant adjusts to the change. This is temporary and normal. As long as the stems are not pulled too tightly and have room to move, the plant will continue to climb and fill out beautifully.

For now, the best approach is simply to maintain your current care. Keep the soil free-draining, water only when needed, and provide light feeding during the warmer months. With the healthy new growth you are already seeing, your Mandevilla is on the right track and should continue to flourish as the weather becomes more consistently warm.

If anything changes or becomes more concerning, please get back in touch, but at this point, I don't see anything particularly concerning.

Jacob

[Rosana1]

Thank you, Jacob. I did think the photos would not show it all, as I had cleaned most of the yellow leaves, but I'll follow your advice and keep an eye on it. It is such a beautiful plant!

Have a great week, and thanks for the advice.

Regards,

Rosana

[JacobZ]

Hi @Rosana1,

The main thing that makes me think it will be fine is the new shoots. When plants are struggling, they divert energy away from new growth, so the fact you are seeing new shoots, even with the leaf drop, tells me that your Mandevilla isn't really struggling too much.

Keep an eye on it, but I think it will be fine.

Jacob