Growing Meconopsis in the garden
Where is it easiest to grow them?
Meconopsis come from the Sino-Himalaya, and in their natural environment they grow at very high altitudes, where they are covered by lots of snow in the winter and are exposed to monsoon rains in the summer.
These conditions make it easier to grow them in the western and northern parts of Britain, where the rainfall tends to be higher and the summers are cooler. Meconopsis are also grown very successfully in northern, maritime climes all over the world, with areas such as northern Norway, Alaska and north-western Canada and the USA having a long tradition of success. It is remarkable that plants flourish north of the Arctic Circle, when their home is not so far from the tropics – but high in the mountains.
Although they tend to favour the wetter and cooler parts of Britain, with good soil preparation, measures taken to increase the humidity, root competition kept to a minimum and some other key factors taken into consideration, they have been successfully grown all over Britain, in many other parts of Europe, in northern states and provinces across North America, in New Zealand and even some in Australia.
Which are the easiest kinds to grow?
This section on cultivation is mainly concerned with the big blue poppies, which are the most popular, and the easiest to grow. Techniques are similar for the big monocarpic species, such as Meconopsis ×complexa (often called Meconopsis napaulensis in commerce), for Meconopsis punicea, quintuplinervia and their hybrid Meconopsis ×cookei, and for the yellow-flowered monocarpic species, Meconopsis integrifolia and its relatives. The smaller monocarpic species, mostly with purple or blue flowers, are generally more difficult to grow and need rather different conditions. These are mentioned at the end of this page and on the seed-raising page.
In general, deciduous ones are easier to grow than evergreen ones, because they are less susceptible to rotting in autumn and winter. So good news! The big blue poppies are the easiest. Meconopsis ‘Lingholm’ is widely available, and is recommended as a great introduction to the genus.
Meconopsis integrifolia subsp. integrifolia
As with all plants, we will grow Meconopsis most successfully if we prepare the soil well. It needs to be well dug, loose, friable, nutrient rich, moisture retentive, but not prone to water-logging.
If the soil is heavy and likely to become water-logged in the winter, add plenty of coarse sand or grit, allowing it to drain freely. Conversely, if the soil is on the dry side it is important that lots of moisture-retentive material, such as garden compost, well-rotted manure or leaf mould, is added to the soil. This will help to stop the plants from drying out in the summer, and to keep humidity high. Manure, or other fertiliser, gives healthy plants, which are much more able to cope with stress.
In winter, in their natural habitat, Meconopsis are dormant, under several feet of snow. This keeps them fairly dry; it is important that this is replicated in the garden environment. This can be achieved by planting the plants on a slightly raised small mound, which can be created when grit, compost, manure etc. are added when preparing the soil. The mound will allow the water to drain away freely.
Meconopsis thrive in areas of high humidity in dappled shade; they dislike being in full sun. The shade can be created by deciduous trees, but it is important that they are not too vigorous or shallow rooted as this can create too much competition for the available water in the soil. In the south of the UK they are often sited by water, planted on the banks of stream or pools. This both provides water to the roots and raises humidity. A suitable site is easily recognised by the growth of moss.
Meconopsis also dislike being in very exposed areas, where the wind can damage their rather brittle stems and leaves, or bend the flowering stems.
Mulching and feeding
Meconopsis benefit from a mulch, typically of composted bark or well-rotted leaf mould. This can be done in the autumn, when it is often applied to other parts of the garden, or whenever plants are planted out. About 5 cm depth is good, but it is important that the crown is left unmulched, as this can cause rot to set in.
Mulches can also be beneficial in the summer where they can increase humidity around the plant and help with water retention in the soil.
In the wild Meconopsis grow in very nutrient-rich soils, benefitting from lots of passing yaks! It is important that they are fed well with manure or a general purpose fertiliser each year, and more regularly if the soil is very poor.
In the wild Meconopsis grow where the monsoon brings lots of rain in the summer. If you live somewhere that can be dry in summer, it will help if you can ensure that your plants never dry out. Water at the roots is essential; high humidity and/or regular water or mist on the leaves is valuable. If you will be away at a dry time, you should organise automatic watering or good friends! And of course, water new plants well.
It is difficult to over-water Meconopsis in summer, short of drowning them, and deciduous ones are remarkably tolerant of winter rain. Evergreen kinds, such as Meconopsis ×complexa (napaulensis of cultivation) and M. superba, with their wonderful rosettes, and the yellow-flowered M. integrifolia relatives, can rot if the hairy foliage gets too wet, so overhead protection is advisable. A sheet of glass or polythene on a glass or wooden framework works well.