Some of the most beautiful spring-flowering plants that grow well both in sun and shade are forms of pulmonaria. I first remember seeing this form of the lungwort at Beth Chatto’s garden in Essex when we visited as horticultural students from nearby Writtle College. It was then planted in an inspiring combo with Spirea ‘Gold flame’. The latter had been cut hard back so that its vivid new shoots – in shades of orange-red – were timed to contrast beautifully with the deep blue flowers of this pulmonaria.
While there are a whole host of different forms of this robust, herbaceous perennial, ‘Azurea’ earns its place in the garden by having some of the darkest blue flowers which open from pinkish buds. It also bears plain green foliage which makes a good background contrast to the silver- and spotted-leaved forms of the same species, as well as to other plants.
I like planting this pulmonaria under the edges of deciduous shrubs where it can be seen blooming before the foliage emerges on the bush above. The greener leaved forms can tolerate this situation well, whereas the more variegated types can suffer badly from mildew when they’re stressed by dry soil and enclosed by other plants in summer.
HEIGHT: 30cm (12in.)
These dimensions refer to the ultimate height and spread that you can expect shrubs or trees to reach in 10 years with moderate pruning. Some woody plants may be maintained at a smaller overall size – for example, cutting coloured-stemmed dogwoods or willows back hard each year. Fruit trees and bushes may also be controlled in size by pruning.
For herbaceous perennials, the dimensions represent the height and spread reached in 5 years. Remember that these plants will usually reach their maximum height in the first couple of years, but may spread more slowly. In addition these plants do not produce woody growth and taller sorts will often be cut down at the end of the winter. This category also includes spring and summer bulbs.
With annuals and biennials, the dimensions refer to the height and spread in their lifetime – either a single growing season (annuals) or spanning two growing seasons (biennials).
SPREAD: 45cm (18in.)
SOIL: Clay, loam or chalky soils, acid, neutral or alkaline soils. Moisture-retentive, but free-drained.
The type of soil in your garden will determine which plants you can grow. At the most basic level, soils vary according to their acidity or alkalinity (pH), and their texture/structure/parent material. Soils of pH6.5 can grow the widest range of plants, while loam soils that are composed of different soil particles – clay, silt and sand – are reckoned to be the best type of soil for gardening.
In the UK and Ireland, most soils vary between pH3 and pH8
Very acidic soils: pH3 to pH4.9
Acidic soil: pH5 to pH5.9
Moderately acidic to neutral soil: pH6 to pH7
Alkaline soil (limey) pH7.1 to pH8
Heavy soils usually contain small mineral particles
Clayey soils are densest and therefore heaviest, based on very small particles of clay. They can be poorly drained and lacking in air, especially if compacted.
Silty soils are composed of fine, river-smoothed particles that pack together closely and can be prone to compaction or being washed away.
Light soils are composed of larger particles
Sandy soils have larger particles in a range of sizes which prevents them being packed together and thus leaves them open to aeration and freely drained.
Peaty soils tend to be almost exclusively based on the weathered organic remains of mosses or sedges. They are usually dark in colour and fibrous.
Chalky/limey soils are usually pale in colour with visible lumps of chalk and flinty pebbles.
ASPECT: Full sun, part or dappled shade. Best in a north-, west- or east-facing location.
This is an indication of the amount of light that a particular plant requires in order to thrive, as well as suitable orientations in which it can face.
Light levels are usually listed in the following range:
Full sun – site with full sunlight for at least 10 hours in summer and 6 hours in winter, with overhanging branches and foliage of other plants.
Part shade – position that is shaded for part of the day by a structure or natural feature, usually getting sun for 5-6 hours in summer and preferably a few hours in winter.
Dappled shade – where direct sun is partly blocked by the foliage of trees, shrubs or other plants that lose their leaves in autumn. Although reduced, dappled shade is often at a consistent level through the day.
Full shade – little or no direct sunlight but usually with diffuse, ambient daylight. Such shade may be found in a courtyard enclosed on all sides.
Deep shade – The lowest light levels, found at the base of a shaded wall or under the dense canopy of an evergreen tree or shrub.
Orientation is normally listed as follows:
North-facing (between NW and NE). Low, but steady light levels and temperatures throughout the year, although exposed to cold, northerly winds. May receive direct sunlight in early morning or late afternoon during summer.
East-facing (between NE and SE). High light levels and temperatures in morning – which can be a problem after a winter or spring frost. Exposure to potentially cold and dry east winds and high temperature fluctuations.
South-facing (between SE and SW) Potential to receive high light levels and tempertures all year round. Can be very hot and dry in summer, but affords useful shelter from the worst of the cold in winter.
West-facing (between SW and NW) Usually the mildest orientation with high light levels and temperatures in the afternoon. Protection from coldest easterly and due northerly winds in winter and spring.
HARDINESS: Hardy down to -20C
The Royal Horticultural Society lists graded RHS hardiness ratings for plants from H1 to H7, but in a simpler form, most garden plants can be identified as follows:
Tender – can’t survive frost and requires temperatures above 1 Celsius to thrive. Best brought under cover in winter.
Half-hardy – tolerant of short periods of frost down to -5 Celsius, especially in sheltered locations.
Hardy – can survive temperatures down to -10 Celsius in average UK winters.
Very hardy – able to survive temperatures below -10 Celsius in the coldest UK winters.
Some plants can be considered ‘root hardy’ which means that the top growth may be killed in frosty conditions, but the roots will survive underground to produce new shoots in the spring.
In the British Isles, the mildest winter temperatures are found in coastal areas, particularly in the south and west. Meanwhile, inland locations will experience the lowest winter temperatures.
Click on Height, Spread, Soil, Aspect or Hardiness for general information about these terms
