Without the putative sycamore, north- and east-facing walls present few problems, though you may not get as colourful a display as on sunny walls. Foliage will be excellent. North walls are almost easier than east. They get no direct sun at all, though in summer a few slanting beams may drop in at the beginning and the end of the day. In a new garden, you need to spend some time watching walls and the amount of light they get before you start planting anything at all.
East walls are more treacherous. They are cold, but get a burst of sun, if there is any, at the beginning of the day - fatal to plants frosted overnight. Most people know that east walls are bad news for camellias. Other plants can react just as badly. Cells that may be frozen need to thaw out gently, just like water pipes. An early blast of sunshine may cause too quick a thaw, rupturing cell walls. Plants collapse and may die. I lost a 30-ft `Mermaid' rose on an east wall, though it had a trunk as thick as my arm and seemed invincible. Chaenomeles and pyracantha have never been affected. More surprisingly, neither has the evergreen shrub piptanthus, with its fine, hand-shaped leaves.
The chaenomeles (japonica) is already in bloom, with blood-red flowers on dark wood. I like them spreadeagled on a wall, pinned flat and pruned fairly severely after flowering to eliminate twigs that try to push forward. This makes it easier to grow other things in front, but also seems to give it a more oriental air, like the two-dimensional branches of japonica you see in a Japanese print or a piece of fabric.
`Crimson and Gold' is the one to go for if you like your colours rich and uncompromising. It will not grow much beyond 4ft. `Knap Hill Scarlet' is equally brilliant. If gentle introspection is more your thing, choose the gentle, pink-and-white `Moerloosei', fast-growing, wide-spreading, and reaching eventually to a height of 8ft, though its spread may be twice as broad as that.
Pyracantha is also best when it gets some corrective training. Some time ago, I planted one on our east wall, to the right-hand side of the kitchen window, a biggish window of old-fashioned, small square panes. Over the years I've trained the pyracantha to make another "window" alongside, the branches criss-crossing to make "panes" against the walls. It's slightly dotty, but it makes me smile when I turn in at our gate. The blackbirds like it, too.
Pyracantha was one of the wows of James I's garden, when it was a rarity newly brought in from the east. It is very popular now, and deservedly, as happy on a north wall as it is on an east one. It is evergreen and gives two meaty performances a year. I prefer it in berry to when it is in flower. Bees think otherwise. It is spiny, but not viciously so, and is not difficult to handle.
The blossom is the same on all varieties, white with a heavy, musty scent. Berries can be yellow (`Flava' or `Soleil d'Or'), orange (`Orange Glow' or `Orange Charmer') or red (`Dart's Red' or `Watereri'). I am not fussy about the times I trim pyracanthas to shape, leaping in with the secateurs whenever the whiskers of growth start to get in the way of the chequerboard pattern.
I started by training one stem up the side of the window, then choosing horizontal branches to train out from that main stem. You have to wait for suitable growths to present themselves, but pyracantha is so vigorous that that is rarely a problem. When there were six or seven stems stretched out parallel at about 15-in intervals against the wall, I started looking for upright growths sprouting from the horizontals that would turn the straight lines into a series of squares. It is far more complicated to describe than it is to do.
Fire blight, a fungal disease that floats in on the air and ravages the foliage, is pyracantha's worst enemy. There is no cure. But don't lie awake worrying about this scourge. It may never happen.
Because rain tends to come in from the south and the west, north- and east-facing walls and fences act as barriers, preventing the ground under them from getting properly wetted. Wall shrubs on any aspect do better if they are planted a little distance - say, 18in - out from the wall. The ground will also retain more moisture if you dig in a good quantity of manure and compost before you plant. Mulch all wall shrubs regularly in autumn and spring.
There has been no lack of water this winter, but drought is not just a summer problem. East and north walls face winter's coldest and most drying winds. Evergreens suffer more than deciduous shrubs. Foliage loses moisture faster than the roots can take it up. Leaves turn brown and die.
This gloomy scenario need not worry us this year, at least. Too often gardening is seen as a series of problems to be overcome rather than pleasures to be indulged. Here is an excellent pleasure for an indulgent north wall: Azara microphylla. This shrub has small dark, shining, evergreen leaves and powdery tufts of bright yellow flowers that smell strongly of vanilla.
It will not do well on excessively limey soils and may keel over completely in a tough winter. In pampered city gardens, wrapped in the central heating that escapes through windows and doors, it will thrive. It flowers in March, needs no pruning and suffers from no particular nervous tics - a paragon.
Where there is some shelter from wind, the twining climber Celastrus scandens will perform well on a north or east wall. Its season is autumn, when the orange-red seed vessels produced from insignificant flowers explode to expose startling red seeds. It is very vigorous; it likes a good mouthful of fence or porch to get its teeth into. Once established, it needs little nannying.
All these plants will give brilliance to shade. If you want something cooler, choose the white-flowered climbing Hydrangea petiolaris. Or plant the compact upright shrub Euonymus fortunei `Silver Queen', with its fine variegated leaves. When it is established, thread it through with a pale clematis such as `Marie Boisselot' or `Lady Northcliffe'.
Variegated Cotoneaster horizontalis is another great beauty that thrives in shade.
Make it the mantra for the year: Shade is Good.