Your peppers and tomatoes won't be able to be planted outdoors until early June because of the risk of a late frost. However, look around plastic recycling tip bins for the large square 5 litre mineral or squash plastic bottles and cut the bottoms off. They make ideal protective individual cloches. If my tomatos start looking leggy and need to be planted outside, I plant them out and slip the open top over a tomato cane to hold it in place and act as a cloche until the weather has warmed up. Similarly, you can plant your peppers in bigger pots (preferably 8 inch diameter) and slip one of these plastic cloches over the plant achoring it with a stick. If you locate your pots outdoors in a sunny place, you can probably get away with putting them outside earlier as long as you've got this protection over them.