[Pescador]

Harvested my 1st ever horseradish today, this root was 70cm long and approx. 1.5cm diameter.
Back in the spring I planted a thong in a bottomless bucket buried in the soil.
This root had come out from the bottom of the bucket and upwards to within about 25cm of the surface. Then continued at that depth for 50cm before going back downwards again. As you can see from the thickness of it, I must have left plenty in the ground at both ends, which is more than a little worrying!
Should make a lovely sauce to go with the Rib of Beef on Christmas day!!

[sunshineband]

Good idea to grow it in a bucket as it can go really deep and is the devil's own job to dig some up 

[Plot 1 Problems]

I've used the base of an old damaged compost bin as a planter for my horseradish, about two foot tall and it's been great! I planted two thongs this year and dug a couple of decent roots like yours to make some horseradish sauce. It was delicious, not as fiery as I expected, but much tastier than the jarred stuff

[victoria park]

Those narrow long roots snake everywhere. Far more invasive than mint.
On the fiery thing, you might find that some of the narrower roots and some of the thickest roots aren't as hot. My horseradish for two years was very hot, but for the last couple of years not so. Yes, the taste is there and the heat can be augmented by mustard, but I haven't worked out why the heat has disappeared.
Accepted advice is the middle sized roots are the hottest, but I'm wondering if the soil and/or weather has an input. Anybody out there have any experience ?