Reaping rewards on the allotment - One year's seeding - seven years weeding

Autumn seems to have come early this year - but then we had our summer in the South of England in April and May and the weather has been wet and dull for much of the time since, until this week. 
And just when there is so much to do on the allotment, the temperature has soared to 28 or 30 degrees, especially up there where there is no shade at all.
My first and urgent job today was to carefully remove all the poppy heads, especially those that have ripened and are full of seeds, carefully collecting those into a bucket for storage and disposal elsewhere - not sure where yet. Anyone want a field full of oriental poppies that will appear year after year into perpetuity?!
One year's seeding is seven years weeding, and that is a wise old adage true not only of the poppy, but of many other weeds - chickweed, dandelion, teasels, groundsel, ragwort, scarlet pimpernel and many others. And once weeds like dandelions take a hold in numbers and get their deep perennial taproots down into the ground that spells double the problem. So keep on top of those weeds before they seed!!
Other plotters often ask me how I keep on top of the weeds, and that is one vital ploy. But there are other useful tricks:
1. Rotate a potato crop around the plot. The cultivation of these cleans up even the trickiest soil - by smothering everything else in sight as the plants grow, but also by means of the cultivation necessary - the digging, pulling out perennial weeds along the way, the planting, drawing up the ridges, digging up the plants for harvest, etc.

2. Do not rotavate the plot with a mechanical digger!! Yes I mean that! If you cannot manage digging by hand each year, then have raised plots of such a width that you don't have to walk over the soil at any time. Then a light forking over as necessary suffices. My observation of other plots that have been well and truly rotavated mechanically is that millions of weeds come up in no time at all and unless these are quickly removed, the plot is out of control in no time at all!
3. Plants crops a little closer than the recommended spacing - smaller crops result but more weeds are smothered.
4. If you have some bare ground between crops,either sow some "green manure" seeds like alfafa that are dug in before they seed, or cover with some old carpet or black polythene or, even better, lots of manure if you can get hold of it (unless you intend to grow root crops such as carrots on the plot afterwards - they won't like that.
That's enough for today - next time up there I need to do some harvesting, sowing, and emptying the bin that's full of ready- to- spread compost - so that I can start filling it up again!