In fear of the Narcissus Fly

[Martin Baxendale]

My daughter won't let me use her squash racket 

[RichardW]

A couple of comments; firstly in my garden Galanthus generally dont grow well in positions where they dont get any winter sun. The soil here is very heavy and I suspect tat it is just too cold and wet for them to thrive.

Ditto, in fact the areas that are very shady are now only really planted with lattice pots.

I'm fairly philosophical about bugs and beasties, I have lost nice bulbs to both over the years but have to accept it, particularly in a garden of 7 acres surrounded by lots of wildlife that isn't always welcome. Virtually All my new acquisitions go into lattice pots for a few years to bulk up, have found this works very well, gives some protection, good growing conditions and not lost anything yet.

[Alan_b]

Just to clarify, I presume Richard uses lattice pots primarily to replace his normal heavy clay soil with a mixture better-suited to snowdrops.  I myself have tended to use raised beds to control the growing medium but still have lattice pots to confine the snowdrops to a well-defined location and in the hopes that they provide protection against predators.  So whilst many of us use lattice pots, we don't all do so for the exactly same reasons.

[RichardW]

Yes sorry I'm also on heavy clay so use a free draining mix to give them a better chance.

even in the areas where the soil conditions are better I'm still using them after a few years of trials, there are a few downsides but for new bulbs especially singles I think they are well worth using.

[uvularia]

So, Richard, do you just bury the lattice pots filled with free-draining compost in the clay soil?

[RichardW]

Yes, mix is John Innes, general purpose compost, sharp sand and fine well rotted leaf mould, some are also sitting on pea shingle/sharp sand to give extra drainage & prevent a pan forming under the pot. Results have been very good & I'm sure some varieties I struggle with wouldn't be here/doing so well without them.

[Lesley Cox]

I have to agree with Mark that systemic insecticides are the only real way to keep narcissus fly out of all plantings of Amaryllidaceae. Spraying of the foliage as it emerges then further sprays through the season is effective but also, so is the fingering in around the clumps of insect-repelling granules such as Diazanon, Carbaryl and others. suSCon green is also very good and works totally. One needs to remember though that these chemicals are not only very dangerous to other insects and wildlife but to humans and pets. Many are now banned for use by home gardeners anyway. We in NZ have a systemic insecticide/fungicide called Shield, mainly for use on roses. It works well and is, I suppose, relatively safe.

I do think one needs to take some measures to protect plantings in the small garden situation. Learning to live with some of the pests may be a solution for large gardens where the bulbs may be present in many hundreds or thousands but when one has a few pots or garden clumps, it doesn't take many narc fly to deplete one's stock altogether. The swatting option is fine for those seen but how many flies go unseen or missed? As well as removing dead foliage, the surface of the compost/soil around the clumps or on top of pots should be well disturbed and fingered or forked over so that there are no obvious entry points. Holes show the way though I suspect a fly could get into the tiniest space in search of its quest to populate the earth.

[Diane Whitehead]

I've planted hundreds of narcissus, none of which survived.  However, there
is one area where they have multiplied prodigiously.  I finally figured out why.
The ground is thoroughly infested with one of our natives, Vancouveria hexandra,
despite my having attempted destruction of it every year for several decades.
This plant's roots are filling every bit of the soil from the surface down a garden
fork's depth.  It is deciduous in winter, but very leafy the rest of the year. The
daffodils come up through it easily, but the fly is obviously deterred.

[Alan_b]

I find it odd that we have two reports of narcissus fly attack from opposite sides of Canada but in both cases so severe as to destroy the narcissus population.  To me this raises the question of what is sustaining the fly population?  Do they turn their attention to some indigenous Canadian bulb in the absence of narcissi?  Otherwise how could they be present in such large numbers?     

[Maggi Young]

The little blighters are happy to chomp other amaryllids -
http://pacificbulbsociety.org/pbswiki/index.php/NarcissusBulbFly - so who knows what they may adapt to  if need be? 

[emma T]

I wonder if I could train my dogs to sniff out fly infested bulbs ?

[Maggi Young]

I wonder if I could train my dogs to sniff out fly infested bulbs ?

Yes, seriously, Emma, it should be perfectly possible to train a dog to do that - if they can be trained to detect, cancers, explosives, drugs, money, truffles -    manky bulbs  should be a doddle.

[Alan_b]

I wonder if I could train my dogs to sniff out fly infested bulbs ?

I thought of a similar idea a year or two ago that I might have mentioned here - but I don't have a dog with which to put it into practice.  When bulbs are damaged by disease or insect attack they frequently rot.  If you dig-up a rotting bulb then the smell is very strong indeed so I thought a trained dog should be able to identify such a bulb whilst it was still in-situ.     

[mark smyth]

A couple of comments; firstly in my garden Galanthus generally dont grow well in positions where they dont get any winter sun. The soil here is very heavy and I suspect tat it is just too cold and wet for them to thrive.

About half of my collection are in the beds and troughs at the back of the house where they will get no sun until maybe March

[johnw]

  To me this raises the question of what is sustaining the fly population?  Do they turn their attention to some indigenous Canadian bulb in the absence of narcissi?  Otherwise how could they be present in such large numbers?

Alan:

Simple.  Annual Dutch imports by the boatload.  I suspect here it is mainly an urban problem for the time being.  As well we import many Narcissus from BC.

johnw     - +5c and drizzle.