Height 30-75cm (12-30in)
Planting distance 23-30cm (9-12in)
Flowers early to late summer
Sunny or lightly shaded site
Hardy annual and biennial
Their heavenly scent and dense spikes of pastel and rich-colouredhave made stocks age old favourites for cottage gardens, formal bedding schemes, mixed borders and as cut flowers. The spikes are borne on erect stems clothed with narrow, grey-green and felted leaves.
Most garden varieties have been developed from Matthiola incana, commonly known as stock.
‘Brompton Stocks’ are upright bushy plants reaching 45cm (18in) high. These late spring-flowering stocks have single or double blooms and come in shades of red, pink, purple, yellow and white. Usually sold as a mixture, they should be treated as biennials.
‘East Lothian Stock’, sometimes known as the Intermediate group, produces bushy plants reaching 38cm (15in) high. They bear flowers in mixed colours throughout the summer and can be grown as annuals or biennials.
‘Night-scented Stock’, the common name for Matthiola Bicornis, is a 38cm (15in) high annual plant with a bushy habit. The lilac-grey or purple flowers, which are borne from mid to late summer, remain closed during the day, but at night they open to release the sweet fragrance for which they are renowned.
‘Ten Week Stocks’ are exception-ally fragrant, early-flowering varieties in mixed colours which, as their name implies, flower 10-12 weeks after being sown. Varieties include ‘Dwarf’ which has compact plants 30cm (1ft) high, carrying large flowers in mixed pastel and rich colours. They make ideal bedding plants.
‘Trysomic Seven Week’ produces dwarf bushy plants 30cm (1ft) high. The double blooms – in mixed colours — come out seven weeks after sowing, making them the earliest flowering stocks. Treat them as annuals.
Sow annual stocks – ‘Ten Week’, ‘East Lothian’ and ‘Night Scented’ – directly in the flowering site in, just covering the seeds with soil. They grow in any fertile garden soil in either sun or partial shade. Thin the seedlings to stand 30cm (1ft) apart.
For early flowering, sow under glass in late winter to early spring and keep at a temperature of 13-15°C (55-59°F). Prick out into boxes and harden off in a cold frame before planting out in mid to late spring.
The ‘Trysomic Seven Week’ and ‘Selectable Doubles’ – strains with double flowers – should be sown under glass, as already described, the temperature lowered to 10°C (50°F) for a couple of days before pricking out. This drop in temperature will exaggerate the difference in seedling leaf colour between the pale yellow-green double plants and green singles. Discard the singles if double-flowered plants only are wanted.
The ‘Brompton Stocks’ are treated as biennials. Sow the seeds in a seed bed in early summer. Thin when the seedlings are large enough to handle and then transfer to the flowering site in autumn, setting the plants 30cm (1ft) apart.
All stock varieties thrive in fertile soil in sun or light shade.
Pests and diseases
Flea beetles may attack seedlings, eating small holes in the leaves; caterpillars feed on the leaves of older plants and aphids can be a problem. Troublesome diseases include club root and.