Whilst you could, I suppose plant early peas and strawberries in that container it would not be companion planting. Companion planting is where one plant helps to deter an insect infestation in another, for example, growing a row of carrots between two rows of onions or garlic.

Is the container lined with some sort of plastic material and, if so, does it have drainage holes in the bottom.

Copy and paste this link to your browser for a full list of companion plants:
http://bit.ly/v7gr62

Not totally relevant to your question, but my Grampy used to plant Nasturtium with his Broad Beans - the blackfly went for them everytime.

thank you, Moon growe and Meanie, Novice in me coming to the fore Moon grow.
I was thinking using the dormant time of the strawberries to allow the peas to grow. The trough is lined with poly/weed membrane with a 1inch channel at the base of each sloping side.

Early peas and strawberries will be growing at the same time and if you are not careful the peas will smother the strawberries. I'm still concerned that you do not have adequate drainage, I'd make lots of holes in the membrane... out of interest why did you use it?

I saw them at the Harrogate Show in Sept. and they were lined there, (stitched and made to measure) assumed it was to stop soil/compost falling through gaps in timber.. So took a couple of pics and made my own. The water should drain through the fabric as its the thin type. So in effect they have a 1inch slot 10ft long. Does that sound right Moon grow or would you still advise more drainage. Take on board suggestions re plants, might put strawbs in baskets as last year. So now need sugestions on planting up the tub, 5ft X 2ft X18in deep.

http://bit.ly/v7gr62.
google didnt like the link Moon grow

It looks beautifully made Geordielad!
Not sure what veg you like, but dwarf french beans (available in different colours to be attractive too), trailing cherry tomatoes, Nastertium (great in salads), "ball" type courgettes trail well (add moisture granules when you fill it) and herbs of course.

MG is far better placed to say what works with what than me though.........

thank you Meanie,
got two or three more to make then the top end of deck will be my no bending veg patch. Have made two lower ones to go in front of railings.

Geordielad, you need to copy and paste the link MG gave you into the address bar at the top of your screen. It takes you to an article about companion planting on Wikipedia. You don't involve google in the process.

Highlight it, right click and select the option "go to............"

Bingo, Thx

Oh good you got there - was about to put up the full long link. Yes, on reflection, I think your drainage should be fine.

I was tempted to get a couple of these for my Sister who has a severe back problem. I will follow your progress with interest Geordielad.

Meanies idea about trailing Tomato at the edges is good as they do well in hanging baskets, so should thrive in there.

Ps. You have built it well. I thought it was Garden Centre bought.

Thank you Pimpernel,
these cost less than £30.00, Depending on quality of timber used. I just used standard fencing rails and boards to keep cost down. Minimal diy skill required. Hardest part was joints for cross legs prior to bolting.
thanks to MGs links Im going to try cauliflower and garlic.

Good luck Geordielad!

£30.00...........£155.00 here! Well done you.

and as MG says Good Luck