Posted: 17/03/2016 at 17:31
The best and most ecological way is to dig all the weeds out, just hard graft. The other way is to use a weedkiller, such as glyphosate, unless your allotment rules forbid it.
First things I would sow, and can be done now, are broad beans, peas and onions or onion sets. Then potatoes. Later, when the ground warms up you can try anything really that takes your fancy. Read the seed packets. After the frosts have finished you can plant out tomatoes, courgettes, cucumbers and peppers. Build a frame for runner beans and sow them. They like manure and compost.