Question
Hi, please help - I left my husband's new plant [adult, with about 50 leaves, nice and ready to bloom desert rose] in rain overnight and it was quite cold. Next day when I wanted to point out how nicely it is getting ready to bloom I noticed the first yellowing leaves. Each day I see 4 more leaves getting yellow now. I took it promptly out of the pot (one third of the soil fell out!) and tried to ventilate it in the sun and put in on newspaper so it would dry out more quickly. I am keeping it inside now as soon as the sun sets. I am thinking whether I could disinfect it against root rot with peroxide or KMNO4 solution but do not feel like getting it more wet again. Please help, it still looks like it wants to live and bloom! Thank you, Martina

Answer
Hi Martina,

A single overnight soaking will not damage a desert rose as long as it is allowed to dry out normally after the soaking. After all, that is what we do when we water potted plants - soak them and then let them dry out.

However cold temps below 50 degrees will definitely cause leaves to yellow and fall off. Temps below 40 degrees will damage the roots and may kill the plant. You didn't say how cold it got.

I suspect that is was the cold more than the rain that has caused the yellow leaves.

Unfortunately, your desperate efforts to correct the situation may have made matters worse. The plant needed warmth and a chance to dry out normally. Disturbing the roots has aggravated the problem and exposing the roots to dry air and newspaper was not a good idea. Disinfectants would also do more harm than good.

Try to get the plant back to where it was before you took it out of its pot. Put it back in the pot with some damp soil. The let the soil dry out normally in room temperatures and good light. Resume normal watering after that. Do not put anything in the soil except plain water. Try to be patient and let the plant recover at its own pace. If the roots have not been severely compromised, it will recover slowly.

I know it is frustrating not to be able to do more to correct the situation, but unfortunately this is a case where doing less is better and patience is a virtue.

Please let me know if any of this is unclear or if you have any additional questions. If you would like to e-mail me some photos, I may be able to provide some additional insights.

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Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

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