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18/09/2012 at 21:51

I bought a Heucherella about 8 weeks ago from a garden centre, not only because it looked nice, but because it is famed to be generally disease and pest free. A few leaves were brown at the base on purchase, but this can be normal with potted plants. I tidied the plant up and transplanted with good compost and some bonemeal. The plant seemed to respond by spreading quite fast, but at the same time leaves kept turning orange brown, with shiny brown patches in the leaves which would then start to wilt. I kept removing the damaged leaves, but noticed that the initial spread was quickly being stunted by the disease and now the plant is shrinking as a result. I have looked up problems for the plant on the internet. It is not rust, because the brown patches are shiny within the leaf structure. No raised spots. I then found a picture of a diseased heucherella leaf on the internet and instantly recognised it as the same as my plant. It was bacterial leaf spot , Xanthomonas species. I then realised the web site was American and this disease is a common problem with Heucherella in the states. I have researched so many UK sites, but none mention bacterial leaf spot in the short list of problems that Heucherella can experience. As anyone else heard of it on Heucherella in the U.K?Nathalie S

18/09/2012 at 23:31
Have you looked for vine weevils? Heucheras and heucherellas can be temperamental. Most of them seem to suffer at different times of the year but the newer red nd yellow varieties struggle for me. Cutting older leaves back is a regular treatment for me
19/09/2012 at 01:55

I had a problem with a heuchera last year - a variety called Black Knight. The leaves turned brown and the plant just lifted from the pot - vine weevil grubs were the culprit.

 

19/09/2012 at 22:34

Thanks for that Christopher and Christine. My heucherella is a green variety called Tapestry. I will dig around the roots and have a look.  I 'm searching for white grubs with brown heads? (correct me if I am wrong, I have never seen them before). If I find vine weevil grubs, what is the best way to get rid of them without damaging the plant roots further?

20/09/2012 at 16:22
It sounds drastic but dig it up and remove soil ....preferably over something to catch it...... And wash it. Then replant in good soil, away from previous site. Or, excavate the growing site and hunt for weevils. I would squash them. They may have gone after damage but if the roots are eaten or non existent it will have been vine weevils. Heucherellas recover v quickly and you will be surprised by that. No harm will have been done to plant but cut leaves off to help it resettle. If not weevils try another spot in the garden
20/09/2012 at 16:35

Hi Pebble, Would you believe I've just been reading an old gardening mag and there is an article about Heuchera rust. It says that there is a specific rust disease called Puccinia. I've never heard of it and haven't googled it yet but it is saying that it spoils the foliage and eventually weakens the plant. It then goes on to say to chop the plant down and spray it with Rose clear or Systhane fungus fighter.

Article in Amateur Gardening mag 28th April. Going to google Puccinia now as I have a heuchera. Be handy to know.

20/09/2012 at 17:09

Just popped back to send you this link.

http://www.heucheraholics.co.uk/heuchera_rust.html

Hope it can help you,

Jean.

21/09/2012 at 01:54

 I find the best way to get rid of vine weevil grubs is to soak the root with Provado. It is quite expensive but a capful dilutes to a watering can full. I treat most of my plants in pots with this as I find it the only solution to kill the grubs - which do have a brown  head. If you remove the plant from a pot, wash the root and replant but make sure that you throw the old compost away as it may still have some eggs that have not hatched.

21/09/2012 at 08:18
Christine's advice is comprehensive. Be aware though that Provado over use can damage plants. Maybe twice a year? Say spring and again in autumn. I found nematodes very effective too and prob works out bit cheaper than Provado but can only be used when soil is fairly warm
21/09/2012 at 17:50

I agree over use of Provado can damage plants and I do only use it in spring and autumn.  I only use a small watering can to one capful - of course the larger watering can you use,  more of the liquid is  required but the instructions of dilution and usage are made clear on the packaging.  I have used nematodes but have a lot of plants in pots, including two auricula theatres so I prefer the Provado.

22/09/2012 at 13:39

Thanks for your responses Christopher, Christine and Jean.

I went out this morning and lifted the Heucherella and at first thought I had spotted some vine weevil grubs, but quickly realised they were white worms!  Not many, only about five of the small  wrigglers. 

 Anyway I checked the roots, all seem intact and no sign of grubs and to be honest I was quite relieved. So I have followed Jeans advice on treating the Heucherella for rust ( thanks for the web-link, very useful). I replanted the Heucherella with some fresh compost and root fungi and gave it a good dousing of seaweed tonic. I then proceeded with the drastic haircut and now wait to see if it grows back healthily. I have some Rose clear already in the shed to spray on the new growth when it appears. I will post the outcome

 

22/09/2012 at 14:57
I find Heucheras and heucherellas to be a law unto themselves. They grow well then look under par, they simply just don't grow or they deteriorate. The yellow sorts are a problem to solve for me. I try them in various positions in the garden until they are happy..I get there in the end. I know how to grow them, what they need,etc., but many of the new varieties are not robust enough. I split them too. Often they grow best where the experts say they should not be, viz., in the direct sun. They are plants to be pampered but are worth it. I grow a blue grass, elymus magellanicus next to berry smoothy and all summer long have looked superb. A good lift and clean every year seems good practice.
22/09/2012 at 16:29

Christopher, I must be really lucky. I've got a sugar frosting heuch in a pot in the front. It seems to thrive on neglect as I often forget to feed and water it. It seems to keep most of it's foliage over winter as well but after reading everyones' advice I may plant it in the garden somewhere . It's a pretty little plant and I wouldn't want to lose it. Berry smoothy sounds nice.

22/09/2012 at 19:22
Hiya jean. I think Heucheras do better in pots, for some reason. Another beauty is snowstorm a silver/white leaved plant with red flowers. Yes, berry smoothy is lovely.....more red with really good white flowers. I struggled with another red leaved Heuchera but put it in a terracotta pot and it looks fine......as you said, it seemed to thrive on being neglected. I think the experts suggest planting in pots so if yours is doing well I wouldnt plant it out
22/09/2012 at 20:32

Hmm. may leave it where it is now but will have to re-pot soon methinks . It's not been re-potted or top-dressed for 3 yrs. Best time to do this , Christopher, Now or wait 'till Spring ?

I like the sound of snowstorm.

22/09/2012 at 21:42
Jean, not now. Spring is best. Heucheras benefit from being split. They get woody. They easily pull apart and regrow amazingly quickly. Depends on variety of course.....some are vigorous and some not.
23/09/2012 at 07:53

Thanks Christopher - I'll do it in Spring then . Probally will split it , think it may be about time.

24/09/2012 at 21:42

I agree heucheras are a law unto themselves. I have several varieties in the ground. Caramel does well and also splits successfully.  I also have berry smoothie - in a pot - for its first year and it is beautiful! I hope to split it successfully, in Spring as mentioned by Christopher 2.  I am also glad that your plant did not have vine weevil, though I must admit I have never seen little white worms! Ever.

24/09/2012 at 23:11
I have a feeling using John innis or mixing it with multi purpose helps restrict vine weevils in pots. I tried sieved garden soil and compost in pots for this reason and, although growth was less vigorous, they seemed to be vine weevil free. Gravel mulch too, if fairly thick, seemed to be effective. Any views?
26/09/2012 at 21:39

When potting plants I use multi purpose compost, grit sand to help retain moisture and slow release feed.  I also mulch with gravel but I put crock and then gravel in the bottom of the pot before planting to prevent the vine weevil getting into the pot from the bottom to lay eggs and thus enabling the grubs to attack the roots via the bottom of the pot.  

 

 

 

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