It depends on what you are planting in the respective bed and if it has been neglected in recent years.
I only add manure to my spud beds when planting the puds.
I lightly manure my brassica bed the autumn before planting along with plenty of well rotted compost.
I top up the manure around rhubarb, raspberries and strawberries any time now.
I add manure to individual plants such as squash, courgettes when transplanting to their final growing position.
Well rotted compost is added to other beds as and when required. A sprinkling or general fertiliser such as chicken manure will do well a week or two before planting on almost any bed. Give brassicas a boost with the same fertiliser when they have plenty leaves about half way through their growing period.
