Top of the pots - growing trees in containers
Growing trees in containers is a fantastic and impactful way of bringing height, blossom and autumn colour into spaces with no planting beds, such as patios. They can also help zone a seating or dining area and add shade and scent.
Invest in a pot big enough for the root ball of your tree, leaving room for growth. If you think you’ll want to move the tree around, opt for a lightweight material such as fibreglass, which is also good at retaining moisture. Terracotta is heavier which gives stability, but the porosity means the compost dries out more quickly. And use a loam-based compost, such as John Innes No 3, for moisture retention.
The key when picking a tree for a container is not to choose anything too vigorous. Instead look out for trees such as dwarf varieties. Lollipop trees, with single stems and rounded crowns that can be hard pruned, work well in pots, as do multi-stem trees, which tend not to get as big as single-stemmed trees. Consider if you want an evergreen for year-round interest, or the blossom and autumn colour you tend to get with deciduous trees. Here are some good options to look out for.
Deciduous:
Acer palmatum. These small elegant ornamental trees are perfect for pots in dappled shade. They are slow growing and need little maintenance but do need enough watering in dry weather. Look for smaller varieties such as A. var. dissectum, A. ‘Crimson Queen’, A. ‘Emerald Lace’ and A. palmatum ‘Winter Flame’ - a compact tree with coral-coloured bark.
Albizia julibrissin (Persian silk trees). These are beautiful trees with fabulous pink flowers. Smaller varieties are particularly suitable for pots. They like a sunny, protected position and well-drained soil – expanded clay can be added to the planting mix and or as a drainage layer.
Cornus florida. The smaller variety of these flowering trees are a good option for containers, adding fabulous blossom and autumn colour to a patio area. This is an ideal for an area that receives afternoon shade.
Evergreen:
Olives. These small evergreen trees are a classic choice for a pot. They are relatively tough and can be grown in different shapes from tightly pruned lollipops to more naturalistic loose shapes. The older specimens with gnarly bark exude Mediterranean charm. They like a sunny, sheltered spot. Other silver leaved tree available as multi-stems include pineapple, guava, Feijoa sellowiana and phillyrea.
Osmanthus aquifolium. With its dark leathery leaves, this can make a sculptural statement in a large pot, especially when grown as a multi stem. For something similar try multi-stemmed Prunus lusitanica ‘Angustifolia’.
Bay. These are ideal for pots and make great lollipop shapes. Spring is the ideal time to prune them, to keep them to the size you want, and fertilise them regularly to keep them looking lush. Other options include Ligustrum japonicum and Photinia ‘Red Robin’.