A step-by-step guide to creating your own urban garden by Ryan Carter, who runs a Shanghai-based urban garden design firm (www.cartershanghai.com) which has created incredible roof terraces, patio gardens and terrariums all over town
Think of sun. South- or west-facing windows or balconies are best; luckily, Chinese houses are usually already oriented toward the south. Arrange plants so that the taller ones don’t shade the shorter ones, but so that you also still enjoy a view of shorter ones in front. Arranging plants in lines perpendicular to exposure may be the best way to do this.
Pots and soil
Most plants come in tiny plastic pots and are quite rootbound. Plastic doesn’t breathe, and soil aeration is key to healthy plants, particularly in Shanghai’s humidity. Ceramic pots work best for repotting, particularly unglazed ones. For plants in containers, a mixture formulated for containers is best; this usually involves peat moss or an inorganic soil substitute mixed with perlite or another material that enhances drainage.
Choose a pot around the size of the plant itself, if possible. Place a piece of broken crockery over the drainage hole to keep soil in but allow drainage. Then pour enough planting medium into the pot that the crown of the plant – the place where the stem meets the roots – sits a centimetre or two below the lip of the pot when the root ball is placed on the soil in the bottom. Rough up the edges of the roots a little with a trowel, particularly if they have grown into a solid block, but be careful to keep the root ball from falling apart. After placing the root ball on the layer of soil in the bottom of the pot, angling the plant toward the centre, fill in around the edges with planting medium. Tamp it down as you go and fill to the top of the root ball. I like to place a piece of stone on top of the soil and when watering, pour water on top of it to minimise erosion.
Watering and maintenance
The frequency with which you should water depends on the plant, but a good rule of thumb is to water when a finger pushed a couple of centimetres into the soil comes out dry. This may mean once a week in the winter and daily in the hottest part of the summer. If you choose to fertilise your plants, again, different kinds need different types, but in general you can follow the ‘weakly, weekly’ rule, using a half-strength mixture of a general purpose fertiliser (Miracle-Gro 30-30-30 works well) each week. Removing spent flowers at the base of the flower stem will help many plants continue flowering.
Good, commonly available plant selections for Shanghai:
Tangerine/satsuma A small, elegant tree that doesn’t mind a bit of neglect, has deep green, oblong leaves all year round and fragrant white flowers in mid-spring. It also bears fruit. Likes full sun.
Rosemary Another drought-resistant choice for sunny, exposed locations. Has a charming, expressive bushy habit and in addition to its culinary uses bears small lavender flowers intermittently.
Pomegranate A small shrub to large bush that likes full sun and doesn’t mind a bit of damp. It rewards a modicum of care with bright vermilion flowers.
Agapanthus In a sunny location, and with ample pot space – its roots are rather intense – strappy leaves give way to tall stalks crowned with dramatic sprays of lavender-blue flowers. These occur with greatest frequency in midsummer but can extend into autumn.
Lantana A tender annual that may suffer on the coldest nights; you should not expect it to live through the winter. During even the hottest summer months, though, it spreads and spills over edges and covers itself in pincushions of fragrant pink or red flowers that fade to yellow.