Peony specific advice
The main advice when planting bare root peonies is to not plant them too deeply. The crowns need to be just below the surface with the buds no more than 3cms below the soil. A sunny, well drained site is best to encourage the best flowers from your peony plants, but peonies will tolerate some partial shade too.
In spring, once the plant is growing, use a slow release fertiliser like Vitax Q4 spread around the base of the plant. This will feed your peony during its growing season. You can also mulch around the plant with well-rotted manure taking care not to let any manure touch the plant buds as this can cause them to burn.
Deadhead after flowering but leave the foliage intact until the leaves die back in autumn. The plant will remain dormant in the winter months and then regrow the following spring.
Peonies prefer to stay in the same spot but can be divided every 5 years or so if they outgrow their position.
Bare root perennials will benefit from a soak in a bucket of cold water for an hour before planting, to ensure that the roots are fully hydrated. Dig a large enough hole to plant the whole root, without damaging it, and incorporate fresh compost with the soil to aid drainage. Using a mychorrhizal plant powder sprinkled onto the roots will help to ensure that good root growth is achieved. The powder contains symbiotic fungi that will help the roots to draw in moisture and increase root spread. This boosts the plants overall and they are quicker to establish and produce more healthy plants.
Plant not too deeply but making sure the roots are covered with compost/soil mixture. The crowns (the tops of the plants) should be 2/3cms below soil level. If you can see a tiny amount of shoot or greenery make sure this is just above ground level. Firm gently in, ensuring there are no air pockets under or around the roots and water the area well. This should be all the moisture they need until you can see the plants are actively growing. Once your plants are 15-20cms in height they can be fed using a multi-purpose feed.
Place a cane or label in the ground next to your bare root perennial just before you cover the roots over so that you know where and what you have planted.
*Do not plant bare perennials if the ground is waterlogged or frozen. If you need to plant when a very cold spell of weather is forecast, cover the area with cardboard or plastic sheeting to keep the worst of the cold out.
Alternatively, a successful way to start off your bare root perennials is to plant up each bare root plant into a pot using fresh compost. Ensure that the pot is large enough for the roots to spread evenly in the pot. Plant not too deeply but making sure the roots are covered with compost. The crowns (the tops of the plants) should be 2/3cms below soil level. Water in well and place a label into each pot. Leave until early spring or once the weather is more clement, when they can be planted into their final flowering positions in the garden border.