Picture of Medwyn Williams

Medwyn Williams

Hello. I'm Medwyn Williams – eleven times Gold medal winner at the Chelsea Flower Show, Past Chairman of the Royal Horticultural Society Fruit Vegetable and Herb Committee and President of the National Vegetable Society.

Onions and Leeks for The Tatton Park Flower Show


How lovely it is to have some fantastic sunshine for a change; looking at the weather forecast last night Anglesey was one of the hottest places in the UK, what a change from what we had experienced during Spring.  The only problem now is the watering, you really do need to be on top of it with this persistent heat. I popped into the glass house at the University farm complex this afternoon

and I was extremely pleased with most of my onions.  I say with most as some have had the dreaded Botrytis hit them on the side and just above soil level.

Botrytis hit the onion 09061
Botrytis hit the onion 09061

The problem I have at Aber is that I can’t be there every day and the humidity is often far too high making it a perfect environment for disease to spread.  The onions are all in 25 litre pots in three rows spaced out in domino fashion. The strange thing is that the Botrytis seems to have affected the whole of one outside row and a couple in the middle row with the third outer row totally unaffected. It really is heart breaking when you see a really well shaped onion of good size only to find the dreaded patch of disease on the opposite side.

The good news however is that I may well get the 15 that I need for Tatton Park, failing that I can still make a good stand using just 10. They are undoubtedly the best onions that I have ever grown for this time of year with the biggest onion a touch short of 24 inches in circumference, and that’s after being dressed down to one skin. I have no doubt that they will continue to grow bigger as I am now supplementing the original Professional Slow Release Pellets that was added way back in January to the mix.

Onion with 20 leaves and looks as if it could really be big one
Onion with 20 leaves and looks as if it could really be big one

These Pellets from Everris are without a doubt way ahead of any other that I have used, they really do work throughout their 6 months span. In this case the one I used was The Osmocote Exact Standard with a slow release action of nutrients for 6 months 15+9+12.  This of course means that the nutrients will soon be drained so I am now feeding on a weekly basis with Peters Professional Liquid feed with a high ‘K’ 9+9+36 to harden up the plants a little (Both of the above are available in my catalogue as Items 0026 and 0031).

Having had this success using just 25 litre pots sitting on a bench, I have no doubt that anyone can grow onions to match mine.  The other difference to previous years was by following the advice I gleaned from Peter Glazebrook, water only on the inside rim of the pot and never in the centre. There’s still five weeks to go to Tatton show so towards the end of next week I shall have to pull the biggest and hopefully wait a few days for the others to match them, hopefully! Bear in mind that these onions were sown around mid August last year and were intended for the Chelsea Flower Show and not one has split or bolted on me. It does make you wonder regarding sowing dates.

A good good few onions together all over 22 inches around and  in 25 litre pots 090613
A good good few onions together all over 22 inches around and in 25 litre pots 090613

My leeks have now been on 21 inch collars for over a week in an attempt to lengthen them a little to try and prevent them splitting. A few are now splitting about three flags which I don’t mind as I have still 5 weeks to go and they should throw new roots around the root plate by then. The challenge is if they will pull now as they are already nearly 9 inches around and looking very powerful.  The 21 inch collar is black damp course with the old silvered collar placed over it to try and keep them cool.  Again the slow release feed will now be coming to the end of its life and these will get fed the same as the onions with a high ‘K’ feed.

Another view along the bench
Another view along the bench

I shall check them thoroughly about three weeks before Tatton and if it looks as if they are not pulling or lengthening, I shall remove the 21 inch collar and revert back to the 18. If they haven’t pulled then it’s pretty certain that the lower flags area will be blanched and I certainly don’t want that.  By reverting back to 18 inches I hope the Chlorophyll will get back into the flags in time for the show. Time will now tell how they will perform.

One thing is certain I shall be growing all my leeks and onions in future in pots, it is going to be more expensive, but it’s also a hell of a lot easier with the plants growing at waist high level.

Leek Pendle with 21 inch collars as well as foil around 090613
Leek Pendle with 21 inch collars as well as foil around 090613

Leeks Pendle nearly 9 inches in circumference and still growing well with hardly any pest or disease damage




Growing Parsnips

25th July 2007 I am often asked what is the best method of growing both long carrots and parsnips for the show

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2 thoughts on “Onions and Leeks for The Tatton Park Flower Show

  1. Also a great method if like me, your garden soil is infested with white rot. Expensive yes but at least you’re not throwing away 80% of the crop as it seems to always strike right at the end of the season just when you think you’ve got away with it.

    1. Couldn’t agree more with you, if you want the best then you simply have to invest in it. If you take the pots for instance, and we will be selling these competitively next year, they are such good quality they should last for many many years.

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