I have 6 pots of Japanese Skimmia on my north facing balcony for 2 years. Then 2 turned completely yellow and died a few months ago while I was away. Now the 3rd one turned yellow, from the bottom of the branches. The other 3 are healthy and bigger than the sick one. I don't see any bugs. They all have the same soil and water. I added some 30-10-10 fertilizer twice in the last 2 weeks. No improvement. Can someone please tell me what I can do to save it? Thank you!
Are you adding fertilizer to the sick plant's? If the plant's are already stressed from something...I would not give any fertilzer at all at this point. Off the top of my head, I would re-evalute the watering of your plant's.Too much water can lead to yellowing leave's but I am not saying that's your problem either.
Can you post a picture? I agree with Rachel about not fertilizing plants that are stressed (unless you post a pic and people suspect that lack of fertilizer is your problem). I would also suggest checking your watering, incorrect watering is one of the leading causes of symptoms like yellowing leaves. It's definitely not the only possibility, but it's common and easy to check for so that's where I'd always start. Try sticking your finger down into the pots and see how wet it feels. If it's really wet, then you're watering too much, and if it's really dry then you're either not watering enough, or not watering thoroughly enough when you do water, or maybe the plants are getting rootbound and need to be repotted. Since you mentioned that at least that one plant is smaller than the others, you can't assume that they all need to be watered at exactly the same frequency--what's the right amount for the bigger plants may be too much for the smaller one.
3-5x a week sounds like it could be too much and the yellowing leaves definitely could be from too much water, but you really won't know unless you stick your finger in there and see how things are feeling. You could do the finger test now just to get a sense of things, but the real test would be doing it just before the next time you would have normally watered them. Also, when you water them, are you taking the trays off the bottom and emptying out the water that flows through into them? If not then the plants might be sitting around with wet feet which is not good for them and could be part of the problem.
If you have two plants and one is smaller and you water them both the same, the smaller one won't go through water as quickly as the others so what's a good amount of water for the larger plants may be too much for the smaller ones. And since the bigger ones go through water quicker, if you've been consistently giving all of them just a little too much it may just be taking them longer to start showing symptoms, so if you find out the smaller one's too wet I'd check the others too.
If it were a soil acidity issue, you'd see the newer leaves turning yellow except around the veins would still be green and that doesn't look like what's happening here. Coffee grounds won't hurt plants, but the brewing process removes much of the acidity so if you ever do have a soil pH issue that's not the most effective way to correct it.
I just found the trays attached to the pots can be separated: I didn't know this although I have had the pots for more than 2 years. See I am a real beginner...And I think WET FEET is the problem, especially the sick one, the water poured out from the bottom while the top doesn't look wet at all. Now I have the trays separated from the pot and there is a space between them. I think there is room to breath for the roots now. With reduced water and improved bottom, the sick one may become healthy again. Thanks for all your help!
How are your plants doing? Was the problem solved? I'm wondering if you have changed the soil since you got them 2 years ago? I hate to think that they are dying off one by one. They're beautiful plants.