• AGM plants

    AGM plants have been through a rigorous trial and assessment programme. They are:

    • Excellent for ordinary use in appropriate conditions
    • Available to buy
    • Of good constitution
    • Essentially stable in form & colour
    • Reasonably resistant to pests & diseases

When I was growing up in suburban Surrey, not far from RHS Garden Wisley, we had a climber growing across the wall, just inside the front door. This was grape ivy, Cissus rhombifolia with its bold evergreen leaves divided into three and slightly puckered leaflets. It eventually covered a large area. My father supported it on small dressmaking pins tapped carefully into the plaster and to which its tendrils clung. It meandered round a couple of pictures and along the curtain rail.

Cissus rhombifoliaThe grape ivy thrived in spite of the central heating. The warm, dry air in modern houses is the main enemy of indoor foliage climbers. Most grow naturally in humid forests so the conditions in our homes can come as a shock. Gently misting the foliage and standing the plants on trays of damp gravel helps. Cissus antarctica, with sharply-toothed leathery foliage is similar to Cissus rhombifolia, but a little less tolerant of dry air.

Philodendron scandensIvies in their vast variety are perhaps more often seen as indoor climbers, usually on a wire frame, but are especially susceptible to glasshouse red spider mite when grown in dry, indoor air and often find themselves moved outside where they thrive more dependably.

We also had a philodendron twining up our stairs, P. scandens I would guess, with dark, glossy, pointed leaves, tinted in bronze as they first open. Epipremnum aureum is rather similar but with golden splashes on the foliage. The leaves made bold shapes, and bold shadows, against the pale wallpaper.
Epipremnum aureum

Some of the other Philodendron species, including P. angustisectum and P. bipinnatifidum, bring us much larger, dramatically dissected foliage, similar to that of Monstera deliciosa. But they are reluctant to climb and tend to develop short, stout trunks as they mature into impressiveMonstera deliciosa 'Variegata' specimens – they take up too much space in all but the largest homes.

Like the philodendrons, the old favourite Swiss cheese plant, Monstera deliciosa, and its form with cream-splashed leaves, M. ‘Variegata’, can be started on a moss pole for support but will soon need more extensive structure. Winding the stems around stout nylon fishing line, which is almost invisible, often works well.

One final issue I’ve noticed is that these plants are less often seen in garden centres than a few years ago, and there are few mail order suppliers. Fortunately, the plant centres at RHS gardens usually stock a good range.

Useful links

Looking after house plants
Top ten AGM conservatory climbers


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