There are two types of popular perennial poppies; Icelandic and Oriental. Common characteristics of Poppies is that they are generally easy to grow. The Icelandic Poppy illustrated top left and Oriental Poppies top right, also prefer soil on the dry side which is well drained, and with plenty of sun. The Icelandic poppy , although not from Iceland, developed from a species originating in cold arctic areas and as such Icelandic poppies do prefer cooler growing conditions and are fully hardy, a smaller poppy growing upwards to 30cms or 12". Not technically a perennial but a biennial and self seeder it does make a re appearance each year although not always in the same spot. It's flowers are short lived and blooms are yellow, white, and orange. It is very colourful and makes a great splash of colour in the border. Easy to grow and freely self seeding it reappears in borders from year to year.
Shown on the top right is Papaver Orientale, the oriental poppy, in fact originates from Turkey and Iran and is a big blousy poppy with lots of style and colour, and easy to grow. It has much larger flowers and is a perennial which reliably comes up year after year. It will tolerate a damper soil than the other two varieties. Whereas some poppies are annuals and bi annuals, the Oriental Poppy is perennial bringing colour to the garden year after year.
It flowers late spring to early summer with each stem supporting one large flower. This poppy also likes sun to flower well, but otherwise is not fussy about conditions. The oriental poppy can have quite large large flower heads which tend to bit floppy with a risk it will overlay other plants if not staked. The Oriental poppy is a keen seeder and you will soon have other clumps emerging. The one down side is that the leaves die back on the Oriental Poppy after flowering which can leave a gap in the border. It is possible to get a second flush of flowers by cutting back the flower stems on Papaver Orientale as soon as it has flowered, cut right back to the ground level. Oriental poppies are suitable for the middle of the border, medium height around 45cm - 90cms. Oriental poppies are easy to grow and reliable flowering plants.
If poppies are not the flower for you take a look at Spring and Summer flowering plants.