No plant produces more variety ofshape than ivy. From a handful of species, cultivars have been developed with oval, triangular, heart-shaped, arrow-shaped, crinkled or undulating with many different veinings and variegations. All except the largest are suitable for the pot garden, especially varieties of the British native .
are hardy evergreen shrubby climbers by nature, clinging to their support by aerial , but they will also spread sideways on the ground, or trail gracefully from . In time, the young plant growing as a climber becomes ‘adult’, and bears and fruits on the terminal shoots, but this is not really desirable, for the leaves lose their characteristic shape, and it is best to keep the plants clipped. If you want to cover a wall with ivy, put your pot near the wall and it will grow up it without support. In a more open place, the ivy will trail downward, and you can trim it as you wish.
In a town garden, choose an ivy not too sombre in colour. ‘Goldheart’ is cheerful and sunshiny, with small, dark green leaves with bright yellow centres and crimson. It variegates equally well in sun or shade, but if plain green shoots appear, cut them out. It will grow to 5 feet (1.5 m) or more. An interesting ivy of shrubbier shape, for a pot only, is ‘Conglomerata’, dense and slow-growing, with leaves which are crinkled and wavy. For a row of ivy in front of a window- box, you must have a miniature ivy. Such as ‘Eva’, with small green and cream leaves, or ‘Shamrock’, with small, dark green leaves like those of clover.
The less dense ivies will leave you room in your pot for some bulbs, perhaps daffodils for spring and lilies for summer. Give liquid feeds once a month in the growing season.
macrophylla (mophead group)
Mophead hydrangeas or hortensias are well-loved shrubs for a terrace, theconsisting entirely of large sterile florets without the disc of small fertile florets which distinguish the lacecaps, so that the flowers are dome-shaped, not flat. The leaves are toothed and deeply veined, a fresh, bright green when young. Mopheads have for long been favourite pot plants, partly because of their striking flowers, partly because they are not fully hardy and if grown in pots they can be transferred to a for the winter if the gardener has this amenity. Otherwise the pots can be sited in the shelter of a wall, where they should be safe in mild districts. In cold ones, they can be considered as a one-season pleasure, and replaced if need be.
Hydrangeas are among the last of the pot plants to flower, a delight for late summer. The colours are white, red, pink, blue or purple, but the blue varieties will turn red or pink in alkaline soil, and if you want blue flowers, plants in a standard loam-basedmay need dosing from time to time with a blueing powder. One of the hardiest varieties is ‘Generale Vicomtesse de Vibraye’, which is rose-pink or blue according to the soil, and the old cultivar ‘Madame Emile Mouillere’ is still hard to beat, a white hydrangea with a pink or blue eye.
Hydrangeas need rich soil, shade, and plenty of water – the roots must never be dry – but with a little care they are flonferous and healthy plants. The flowers can be cut off in autumn and dried for winter decoration, but in cold places it is better to leave them on the plant until spring to protect the young buds from frost.