To re-pot or not re-pot?

[David Nicholson]

In the past I have annually re-potted all of my European Primula collection usually in mid May when I move them out of the greenhouse to their Summer quarters. Many of them are quite small plants in 3" or 3.5"  pots with one or two in 5" pots. None of them will require potting on and I do wonder if I could get away with not re-potting this year. What do other growers do??

[Maggi Young]

First, a question: do you have vine weevils around? If the answer is 'Yes', then I would repot, even if the plants are going back into the same size pot, it is a chance to wash off their roots to see there are no nasties lurking, weevil grubs, root aphid etc. and the primula will enjoy the fresh compost.  In a little pot, such as yours are, even quite a small plant will use a lot of the goodness up over a season and repotting little plants is just as easy as cleaning off the top and redressing, in my view.

[David Nicholson]

First, a question: do you have vine weevils around? If the answer is 'Yes', then I would repot, even if the plants are going back into the same size pot, it is a chance to wash off their roots to see there are no nasties lurking, weevil grubs, root aphid etc. and the primula will enjoy the fresh compost.  In a little pot, such as yours are, even quite a small plant will use a lot of the goodness up over a season and repotting little plants is just as easy as cleaning off the top and redressing, in my view.

Thanks to 'Provado' I don't have trouble with vine weevils Maggi. It's really not a job I hate doing (in some ways I quite enjoy it), just wondered if I was making work for myself?

[Maggi Young]

Stand back and wait, David... I'm sure there will be folks who will say just that, that you are making work for yourself. But I have a sneaking suspicion that one of the main definitions of gardening is " making (pleasurable) work for oneself"...... I think the primulas will thank you for it. And anyway, Mrs N cannot, surely, have MORE decorating in mind for the summer? That house of hers must be the freshest home in the country....if she wants more painting and papering, send her up here for a week, I'll show her how the other half live!

[johanneshoeller]

I have great problems with vine weevils. Nearly all looses are a result from their grubs. I have not found a good insecticide in Austria.
I do not repot the Primulas every year, only when they look not so happily or there are demages or the plants are too large (pots too small) and should be propagated. In which concentration do you use Provado??

Hans

[David Nicholson]

Hans, I use 30ml of Provado to 1 litre of water and thoroughly water the plants with it three times each year. Once when I re-pot later this month, again when I put the plants back in the greenhouse at end of October/early November, and again the third watering I do after the plants are woken from their Winter slumber. This seems to keep vine weevils away. One other factor that helps is I use only loam based compost-weevils seem to like soilless compost.

[David Nicholson]

Maggi, all talk and practice of the D word is banned until Autumn at the very earliest

[Maggi Young]

The active ingredient in Bio Provado is imidacloprid, listed on the bottle as Thiacloprid which I take to be a trade name. this may help gardeners outside the UK source the product.

[David Pilling]

State of the art down at the super market is "Provado Vine Weevil killer 2" which it says contains Thiacloprid, compared with "Provado Ultimate bug killer" which contains Imidacloprid and is the stuff you spray on to control aphids.

I presume that there was an original Provado which proved to not be powerful enough for vine weevil.

Provado is a Bayer product, big German chemical company which has global reach.

An (not very helpful) observation is that if you get plants waterlogged the weevils will come to the surface providing a way of removing them. The downside is that whilst some primulas will stand this, many would rot. Also the weevils don't like this and tend to attack the plant above the surface.

[Katherine J]

Could you please tell me the scientific name of this vine weevel? I don't know exactly what it is, and I cannot find it in my english-hungarian dictionary.

[Martinr]

Kathrine, I think the correct name is Otiorhynchus sulcatus.

Martin

[mark smyth]

here's one

It's a myth about them not liking soil. A neighbour grows his own primulas from seed and they were wiped out this year

[David Nicholson]

As my Primula season draws to a close for this year I think I am in a better position to answer the question I posed at the start of this thread.

Overall I think I have had my best Primula year in the short period that I have been growing them. I did re-pot all of my plants in early May and I shall do so again this year. In previous years, after re-potting, the plants were taken out of the greenhouse and placed in a set of covered wooden shelves I use for over-summering my Auricula collection, but last year I left them in the greenhouse but dropped them down a shelf on the North facing side. Not only did it make it easier to handle the plants to see how they were faring, but it was much easier to cater for their watering needs too. It also helped that our Summer was pretty grey and dreary.