Perennial Plants During Winter...

The majority of perennial plants will die back naturally during late autumn, after they have spent the summer working hard producing many flowers they need to rest and gather their strength for the following year. 

Planting during this period does have its advantages it gives the plants plenty of time to get settled, the roots will begin to grow and spread out during the milder winter days and no watering will be required. They will then be ready to push their new fresh growth out of the ground during spring to repeat the process and produce flowers throughout summer again.

How To Plant Your Sleeping Perennials..

Ensure the ground isn't water logged or frozen when planting out of season, it is not advisable to plant into heavy clay soils these are wet and cold and take a long time to warm up during spring the plants may rot if they are planted into clay soil so wait until spring if you have this soil type.

When planting out of season perennials, and you receive your plants, the pots will resemble pots of soil, but the root system is just resting. Plant the perennials as you would at any other time of the year, prepare the planting hole by digging a hole large enough to accommodate the depth of the pot and wide enough to ensure the roots have space to spread out. Incorporate plenty of organic material or compost and plant firming down the soil to expel any pockets of air.