If you have couch grass, you'd be better off NOT rotovating it but digging slowly. Otherwise you'll have tonnes of tiny roots, each ready to make a new plant.

Dig a bit and plant it up straight away instead. Remove EVERY root you can while digging - it makes a huge difference later on. And cover what you haven't dug with cardboard, plastic, whatever mulch you can.

As for plants, why not put a couple of pumpkin, squash and courgette seeds in pots back at the house, and some beans as well. They would be ready to plant then when you need them. You should still be able to put in sweetcorn, beans, peas, salads, spring onions etc in June. I think even carrots too. Do a couple of trays of brassicas at home as well - I found they were great at covering ground last summer when we were trying to clear it. Have a good look around garden centres - some should have some interesting plants still and might even be starting to sell them off cheap now or inthe next few weeks.

Also, consider what you could over-winter. Things like leeks, brassicas, autumn sown onions and garlic, broad beans and peas. Think about where you'd like these to go, digging ground for summer veg straight away but leaving the other areas for a little later - gives you a bit of breathing space, as you can just cover that area up with cardboard etc in the meantime, dig when you can and cover it again until ready to plant. Perhaps the after digging cover could be an organic mulch life well rotted manure or compost to enrich the soil if needed.

One other point on the pre-planning is considering an area for fruit bushes, if you wanted them. This is the wrong time of year for planting, I think, but you ould decide where you are putting them and take the same principle there as overwintering veg spots - cover now, dig and cover until ready to plant.