Perennials for Container Gardens Growing Perennials in Containers
In general growing perennials in container does not differ a lot from growing them in conventional gardens.
In any case, you should take good care of the plants in your container as their roots do not have too much space for growing – therefore it is your task to provide them best possible conditions.
Especially avoid the soil from drying out, and do not allow any standing water in the containers with perennials.
Of course, the sort of soil depends on the plants you are going to grow and the type of containers you have chosen for this purpose.
While purchasing the containers, keep in mind that clay pots and containers make the soil dry rather quickly, and plastic ones do not give that effect. The size matters as well. For example, large containers will preserve moist longer than small ones.
Avoid putting in one container the plants with different requirements to the soil: for example, Baptisia can thrive in the soil with little organic matter, but Peonies require th soil with high level of nutriments.
Gypsophilia needs a well drained soil, and it will flourish especially well if you add some lime into it. Therefore this plant can't be combined with Japanese Irises, for example, which requires an acid and moist soil.
The best mixture for planting perennials for container gardens would include one part of soil from your garden, one part of coarse sand and one part of peat moss.
If you are going to plant the flowers which prefer the moist soil, increase the amount of peat moss in this mixture, and if you want the plants which thrive in a well drained soil – put more sand.
Try to avoid so called 'soilless mixtures' – very often they do not have enough mineral components and usually take a few years to become appropriate for the plants to grow. Moreover, they will dry out much faster and will require daily watering, or even twice a day.
As for fertilizing the perennials for container gardens, use a slow-release substance, like 14-14-14 fertilizer.
Follow the instruction on the fertilizer bag and use the recommended quantity.
If you have the plants which do not require a rich soil to flourish, there is no need to follow the recommendation – you can easily take just a fraction of the dose specified on the bag. Usually you fertilizer your container perennials once every three month,but variations are possible.
Keep in mind that if a plant is naturally winter resistant, its tolerance to cold is much lower if it's planted into the container.
For that reason, it will require some extra protection. Besides, the soil in containers will freeze faster than in flower beds of your garden. It would be a nice solution to take the most delicate perennial plants indoors – it is the safest way for them to survive the winter frosts and snow.
It might be challenging sometimes to take care of the plants in containers, but it is definitely worth that – the containers full of colorful flowers will look great at your balcony, terrace or between the bed flowers.
In any case, you should take good care of the plants in your container as their roots do not have too much space for growing – therefore it is your task to provide them best possible conditions. 
