Fungal diseases

[David Lowndes]

Hello everyone,
I'm new here and this is my first post.  I'm also a new galanthophile.  I started my collection last year using eBay and various snowdrop sales events to begin to build a collection. The site was chosen and the ground prepared with grit and leaf mould.  Bishop et al  was closely scrutinised and I planted up with snowdrops in the green during the late winter/early spring and with bulbs in the autumn.  All were obtained from what appear to be reputable suppliers (although you can't be 100% sure with eBay).
You can imagine that I was really looking forward to this season's growth to see how successful all the planning and hard work have been.  I haven't been disappointed except for what appears to be a potentially serious problem.  The little group of 'South Hayes' didn't thrive.  Well, to be honest, two of them didn't really grow at all.  All that appeared was a shrivelled, yellowish shoot; one with no flower, one with a miniature flower.  So, I dug them up.  At first I thought it was Stagnospora curtisii or Stagnophora gladioloi but, on close inspection the bulbs were a uniform darkish brown all the way through; the feeble stems and leaves just came away as did the basal plate and there were mites.  The bulb wasn't mushy but dryish so now I think it may be Fusarium oxysporum.   The symptoms do fit with the description in the article by Paul J van Leeuwen in The Daffodil, Snowdrop and Tulip Year Book 2014. 
Whatever, I guess they need to be removed, along with the soil so I have started to do this.  Nearby, within a 60cm radius, is 'Mother Goose', 'Green Tear', 'Elizabeth Harrison and 'E.A. Bowles'. Not to mention 'Rosemary Burnham' and a few others.  Rather optimistically I have sprayed all these with a garden centre systemic fungicide but don't hold out much hope for that as a method of control.  There are many other small groups of Galanthus in the immediate vicinity.  So my questions are 'How much soil do I need to remove?' and 'Should I dig up these nearby groups, although they appear healthy, and, if the bulbs  are OK, pot them up ready to move them to a new site'?  I am unsure as to the distance from the original infection beyond which I can assume the soil is clean.  Any suggestions would be very much appreciated.

[Maggi Young]

Welcome David - mercy,  nothing is ever easy is it?  Sorry to hear about this  rather knotty problem - hoping the many galanthophiles, or as I prefer to call them, 'drop fiends, will have some  really useful advice for you.

[Alan_b]

I keep all new snowdrops in pots for the next two seasons after I acquire them to allow any problems to manifest whilst reducing the risk of spreading those problems.  I also test any new ground with inexpensive snowdrops before risking the costly ones.  There are few if any good fungicides available to the amateur gardener.  Beneficial fungi, like Trichderma harzianum, might possibly help to fight-off the bad ones.

[David Lowndes]

Thanks Maggie and Alan.
I'm taking the lack of much response as a respectful silence or, possibly, even an ominous one! This is what I have done so far:
I started with apparently healthy clumps about half a metre radius away from what I have decided is the source, 'South Hayes'.  I dug these up and checked them.  If they were OK I replanted them in large pots with a new mix of gritty compost.  'Mother Goose', 'Green Tear', 'Selborne Green Tip', 'Elizabeth Harrison' and 'E.A.Bowles' were all, thankfully fine.  I will inspect these again when they are dormant.
As I moved closer to the source there were two clumps where just a few bulbs were affected.  Reluctantly I discarded all of them.  This included a really nice group of 'Rosemary Burnham' but I knew it wasn't quite right when it started to show through last month.
Nearest to the source was 'Lady Elphinstone' and 'Primrose Warburg'.  These were also slightly affected and so I dispatched all of them. None of the discarded clumps were fully infected, in some cases just one bulb, and there were no mites.
Then I removed the soil (a metre diameter by 40cm depth) and replaced it with twice as much of a new mixture of sterilised topsoil, grit, sand and tree and rose compost (it was what I had handy!) about 2:1:1:1.  Now there is a small mound which I am expecting to be well-drained.  On reflection it looks a bit like a newly dug grave -I won't pursue that metaphor!
The tools were washed in Jeyes Fluid (what is it with the smell of that stuff?) and the new snowdrop temporary holding area (the green house) has been scrubbed up like an operating theatre.  My wife has offered to help create a new raised bed to act as a quarantine area for future purchases.
I can't do any more!  I'll monitor it and let you know if it has worked.

[Maggi Young]

I think you have indeed taken all reasonable measures, David. Will cross fingers ( since hope costs nothing!) that it works. So disheartening to have these setbacks - I know Jennie S.  has had  more problems this year with the  quite disgusting swift moth larvae and has has to embark on another rescue mission.
Why do we bother?!!
(Cos it's fantastic when all goes well!! )

Pictures of assorted moth larvae and caterpillars : http://www.wildlifeinsight.com/british-caterpillar-galleries/british-moth-caterpillar-galleries/

[Bernadette]

Possibly it would be better to as a new collector to start off with the cheaper but good
doer snowdrops than the expensive ones.   That way you learn what works, soils,
compost mixes, aquatic baskets or not, and get a better feel for them, I've been collecting snowdrops for about 15 years and am quite happy to admit I still know nothing in comparison to some of my friends but my drops are healthy and look pretty and natural in clumps. 
So don't rush in to big purchases like green tear just relax and enjoy collecting them and
every year that knowledge will improve and you will have less setbacks and more confidence. 
To be honest some of my less expensive snowdrops are still my favourites and they are the
stronger growers.

[David Lowndes]

Thanks for the tip Bernadette.

[Brian Ellis]

You seem to have done as much as you can David, I hope it is successful.  I grow in lattice pots and dig them up in the summer (from late May) every two or three years, depending on their rate of growth, and thoroughly inspect them, feed, renew compost etc, split and replant.  I always think if it looks like you have a good looking clump of any variety that is the year to split them.  The next year the clump will not look as good but it picks up again the year after if it is a slow grower.

[steve owen]

David, try disinfecting the soil with Jeyes Fluid.

[David Lowndes]

Thanks Steve, hopefully the smell wears off quicker! What is this Trichoderma ?

[steve owen]

What is this Trichoderma ?

Pass. Not my suggestion.
For possible future reference: if ill-health develops in an in-the-ground lattice pot, I take the pot up and investigate/treat the contents - and fill the remaining hole with Jeyes Fluid, twice on successive days, to the brim, before filling with fresh John Innes 2 prior to any replanting. Tough love but it seems to kill the unwanted organisms.

[Maggi Young]

What is this Trichoderma ?

 A treatment of beneficial fungus , simply put.  A search of the forum from the  search button, fourth from left  in line of options near the top of each page will bring up quite a lot of results - the main page of interest to you will be this one, I think http://www.srgc.net/forum/index.php?topic=6697.0

[David Lowndes]

Steve, when you say 'any replanting' does that include replanting Galanthus?
Maggi, you are the fount of all knowledge (or should it be 'font'?)! I will investigate Trichoderma (translates as 'hairy skin'?) as you suggest.

[johnw]

I have seen stag symptoms on Galanthus bulbs but very rarely on leaves.  Last autumn I got an elwesii that I potted and marked as "QUARANTINE"; I presume I must have seen stag symptons on the bulbs as it would obviosuly have been leafless then. As you can see I had not peeled away any scales, there is a remnant of the tunic.  Clearly the leaves and unopened bud are showing stag, at least to me, but the bulb is presently clean.  The only thing I did was to do a trial treatment with Actinovate in December when soil was very cold though not frozen.  In any event the Actinovate would not have cured discoloured scales nor repaired damaged scales.  I am truly baffled but to be safe have tossed it.

Comments?

photos of both sides.

john

[David Lowndes]

An update.
The bulbs that were moved as a precaution last year are now showing. All were placed in pots and, at first, all seemed to be ok.  This morning I noticed one of the Elizabeth Harrisons, which was just starting to show, had symptoms of Stag and, on closer inspection, so did E.A.Bowles and Selborne Green Tips. So they are in the bin - pots, compost and all.
The good news is that Mother Goose, a second Elizabeth Harrison  and Green Tear seem unaffected so far. These are growing well. I’m hoping this is the end of it but won’t hold my breath. All the snowdrops in the garden seem to be fine including those close to the original infection.
I now plant all new acquisitions in pots for quarantine and scrutiny and I’m not in a rush to plant them out. This is working well as is my attempt at small scale twin scaling.  I’m also planning more raised beds for more delicate varieties. Nothing beats learning from experience - your own and that of others. Thanks again for all the help last year.