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Can anyone tell me what is damaging the leaves on this evergreen Rhododendron
Hi spring jean, is it merely discolouration? It's quite difficult to see on your photo. If so, it might be lacking nutrients, either because the rain's washed them away or because it's not compatible with the soil/compost it's in. According to the RHS plant finder website, they like 'moist, humus-rich, acid soil but will not tolerate deep planting'. So, in pots they usually need to be in ericacious compost. And does it need potting on in fresh compost and a slightly bigger pot?
Give it a dose of sequestrene. It won't turn the current leaves darker green but new growth should be a lot healthier. If you live in a hard water area use rain water when possible or else retreat with sequestrene every 8 weeks through to autumn.
And be careful with the mulching. Mulches must not be too thick or roots will be deprived of air
So, when the leaves are yellow on any plant will sequestrene help? I have a few plants that have yellowy leaves (including a digitalis) and I think it's due to all the rain washing the nutrients away (the digitalis that were in other drier places look healthy). I was going to scatter blood fish and bone around but is that inadvisable?
Yellowing (Chlorosis) is due to lack ofnutrients . this can be because the soil or compost is short of nutrients, or because of waterlogging which can prevent nutrient uptake, or, in the case of acid loving plants, it can be because the soil is alkaline, which stops the roots from absorbing the nutrients. Sequestrene contains nutrients in sequestered form, which is techie for a form allowing them to pass into the roots. Basic sequestrene only has sequestered iron, the main cause of chlorosis. Sequestrene + has a lot more nutrients in this form.
Digitalis is OK in alkaline soil so use something like miraclegro for a quick pick me up.
Oh blast, I just bought the basic sequestrene online and now wonder if I should have bought the +. However, it won't go to waste - a friend has a magnolia with the same problem as the rhododendron so I can give it to him. But that's great about the miraclegro idea for the digitalis - I'll do that, thanks.
I was given this as a gift last spring in a pot, I planted it in this big tub soon after also using ericacious compost. I wondered if I fed it with plant feed ericacious that might help
Are you in a hard water area?
Ericacious feed should help, in a pot it will need feeding anyway. Rain water is best for watering. Every year you should scrape away a bit of the top compost and give it some new ericacious compost. I think it looks hungry.
Hi, some excellent advise on here there's just a couple of other things rhodies can get sun burn so don't keep it in the sun all day and make sure it doesn't get waterlogged and don't let it dry out. It's a good idea to stand the pot on a couple of bricks to be sure it can drain efectively
Rhododendrons don't need much fertilizer. Soluble fertilizers don't last long. so for rhodies in pots it's a good idea to add some slow release pellets, with an occasional Sequestrene+ feed to deal with the acid side of things if you can't provide rain water.
Have you got it in lime free soil?
our water isn't really that hard, but I mainly use rainwater for the Rhododendron. It is planted in Ericacious compost.
The yellow leaves come off easily when touched, will these be replaced by the plant?
Just beneath the flower truss you should see some buds. Once the flower is finished the buds should fatten up. Help them by removing the flower at that point to stop energy going into seed production. If the buds don't develop then it suggests something serious like vine weevil grubs. If you have any vine weevil killer you might want to treat it now just in case. Or you might lift it out of its pot for a quick inspection for grubs, drainage etc..