The trick with this particular plant is to be able to provide it with an acidic, moist, yet free draining soil that won’t dry out – especially during the summer months.Taking this into consideration, when introducing this plant to the garden, the ground will need to be dug over deeply, adding plenty of humus rich and ericaceous (lime-free) compost. Meconopsis also has high nutrient requirements so it’s worth mixing in some well-rotted farm manure as well as periodically feeding with a dose of balanced fertilizer as the plant becomes established. Try and avoid any competition from tree roots, and the area should be partially shaded – preferably from deciduous plants - so as to protect the plants from mid-day summer heat, but also allowing plenty of winter light.In its native habitat the Himalayan poppy is the product of its environment which – outside of the harsh winter months - is permanently watered by the melting mountain snow. Although tolerant of cold temperatures, sharp frosts and heavy snowfalls, if they are over-wintered in wet, soggy conditions, especially around the crown of the plant, then the root system of this stunning plant will fail with no hope of new growth the following spring.Even with the extra work involved in preparing for this unusual yet beautiful perennial, it’s well worth the effort for the reward of those captivating blossom. They first start to emerge in the spring, producing a rosette of light green, hydrophobic leaves. Then in late spring, they will end up a flower shoot sometimes several feet tall. This will produce one or more terminal flowers usually followed by further flowers lower down the stem. If you happen to live in an exposed area you would be wise to employ some kind of plant support as unless they are surrounded by herbaceous plants of a similar height they are inclined to flop over in windy conditions.The flowers tend to nod downwards but some will face upright. Like hydrangeas the soil ph will affect the shade of blue that the flower will display, ranging from a clear pale sky blue through intense pure blue and even on to violet shades. Alkaline soils produce more violet shades even in cultivars which would otherwise be a pale blue.
Pre-chill seed for 3 weeks. Sow in winter or early spring in good free draining seed compost covering the seed with a light sprinkling of compost. Place out of doors in a coldframe or sheltered spot. Keep compost moist, protect from heavy rain but not from frost which is beneficial. Leave for about five weeks then bring into warmth of 13-18C (55-65P).
At two-leaf stage transplant seedlings to 8cm (3in) pots. Keep shaded from strong sunlight. Gradually acclimatise to outdoor conditions and plant out when well established into deep, moist loam in sheltered semi-shaded position, spacing the plants 46-60cm (18-24in) each way.