Slugs Love My Delphiniums

It's that time again. That time when the weather wakes up, along with the slugs. Problem is, the delphiniums are also awake, producing tender new roots - the ideal breakfast for hungry slugs. Yes. There's no doubt about it. Slugs love my delphiniums.

Treating the roots with aluminium sulphate (pellets dissolved in water) at 2 oz per gallon, given at about 1 litre per plant last year, seems to have been successful. This was outlined last year in 'Slugging It Out - Part I'

Not all slugs attack plant roots, but the ones that do - such as the Garden Slug (Arion hortensis Agg) and the Keele Slug (Tandonia budapestensis) - cause devastation.

Aluminium sulphate is a contact poison. This means that it is not ingested (as are stomach poisons, such as methiocarb), but is absorbed through the skin when contacted. So the slugs need to be active, as they probably now are. And if they're not, no matter - aluminium sulphate destroys the eggs.

To help avoid damaging the beetles, which also eat eggs, I poured the solution close to the old stems. Sorry beetles. But I just can't take a chance.

Note that aluminium sulphate only works on small slugs.

Pests Have Favourites - Usually Mine!

Most garden pests can be tolerated, at least to a large degree. And, if left to its own devices Nature has its own methods of dealing with most of them.

I am absolutely fascinated by the ways in which plants can not only resist attack by pests, but also communicate with both insect predators and with other plants, in the process. There has been much research of late, most of which has already been outlined, for example in this review by Sophie Wilkinson.

PESTS HAVE FAVOURITES - USUALLY MINE
If you were with us last year, you will recall the problems I had with snails on a hosta and on some dahlias. But it was only on certain plants, not them all.

This is typical of pest attack. They usually tend to attack just certain varieties and leave others. And these seem to remain attack-free, year after year. So the obvious way would be to keep the ones which survive without protection and discard the rest. This, I do - and given the problems I had with snails on one of the hostas last year, I am also thinking of doing the same here. Problems arise when favourites are attacked. What then?

As you know, I don't like using chemicals for pest control. I know I recommend them, but this is to show that pests can be controlled this way, and also that it's not a closed shop - although I would prefer natural control, I am open to any means possible to control them, especially to preserve my favourites.

But, more than this: There are certain pests and certain types of attack which I am not confident can be left alone. I am thinking of slugs, snails and vine weevils, which attack the roots. I have lost endless plants this way.

I know there are nematodes (these look like tiny worms and enter the pest to destroy it from the inside) which will work in the soil. But these are expensive and will only work in warmer conditions - not now when the slugs are doing the worst of their damage on the tender young delphinium roots, and vine weevil grubs are attacking azaleas, primulas and pansies the same way.

Snailed Again

I knew it! Something told me the other day to check the hostas for snail damage. I forgot. This is the result.

Once these leaves have opened out, they will look awful. So am going to remove them and hope for some re-growth. Don't know if they will re-grow. But I can live in hope.

So much for the prevention methods. Looks like it will be 'back to the drawing board'. Think I might dig up the hosta and put a couple of fuchsias there instead.

There is some possibility that it might not be snails: I have seen a couple of wood pigeons around recently. And the holes do look rather ragged, as if they have been torn, not chewed. But, having said this, there seems to be some slime on the back of the leaves, which would indicate slug or snail damage.

Always follow your instincts. They keep you in tune with your plants more than you might think. This has been my experience.

Slugging it Out Part 1

Nearly lost a blue hosta last year. Slugs reduced it to a skeleton early on - It stayed this way all season, much to my embarrassment. Will try a different approach this year.

Recent warmer damp conditions are ideal for slugs - many have already hatched from overwintered eggs. These pests need controlling before they also start laying eggs (upto 300).

Slugs are usually more of a problem BENEATH GROUND - where they cannot be seen and are safe from frost - than they are above it (although they also cause problems with pots and containers; tending to shelter beneath them). Delphiniums and Hostas are particulary susceptible. I find liquid slug killer is the only way to deal with these. The problem is, which one?

Metaldehyde liquid
Aluminium Sulphate liquid

Yes, I know metaldeyde is poisonous, but we are talking about underground slugs ('Garden Slugs' and 'Keel Slugs'). The problem is that metaldeyde works by dessication (it affects the mucous glands thus causing slugs to dry up), and with the soil being wet, they might survive and become resistant. I have already given them a treatment of this in February when the soil was drier.

Decided to use Aluminium Sulphate. Showers forecast for week, on BBC. Will use pellets at recommended rate, since heavy rain could dilute a liquid too much. [No, I didn't: Weather suddenly changed, so used liquid after all, not pellets, at 50 grams per 4 litres (2oz per gallon)]

Will be coming back to slug treatment very soon. Meanwhile, here are a couple of articles you might find interesting:

Dr. Bill Symondson, Cardiff School of Biosciences: SLUG CONTROL
Earthasy.com: Natural Slug Control

If you are planting seeds outside, look out for new organic slug pellets based on Ferric Phosphate. This looks good for surface use. Not sure if it can be applied as liquid.

And have a look for slugs under your pots!