As long as the compost is still moist and friable it should be fine to use. Peat-based composts have a long shelf life and the nutrients in them break down extremely slowly. We would recommend using the compost in patio tubs and to start feeding the plants after four weeks with J Arthur Bower’s Tub & Basket Liquid Plant Food. If the compost is very dry or very soggy it would be best to incorporate it into your garden as a soil conditioner. Peat-free composts and loam-based composts do not keep as well and are best used within one year of purchase.