Growing Plants in Containers in Full Sun, part I- Shrubs and Trees

As mentioned in previous posts on how extensively container gardening is, from container selection to containers’ arrangements. It is now time to think about the plants that can go into the containers and their suitability. In this article, the selection of shrubs and trees that can be grown in full sun (more than 6 hours per day of sunlight), will be discussed. This is part of a three-part series of growing plants in containers in full sun.

The choice of what shrubs and trees that can be used are quite extensive, as it will give a dramatic, sculptural focal point. The container needs to be large enough for the shrub and tree to not only survive but flourish. If you supply enough fertilizer and meet their water requirements, then many shrubs (not all) can survive, but this is so dependent on the shrubs’ size, and the time it takes to reach this size. As if the shrub gets too big, then container may not be suitable for the specimen in question.

It is also a good idea for the busy gardener to select varieties that can take some neglect. Shrubs and trees need a container that is the right size, but bigger than those suitable for growing perennials.

BIGGER PLANTS MEANS BIGGER POTS

This will allow the shrubs and tree to grow housed in big pots, holding enough compost to meet the plants’ needs. Bigger pots mean the shrubs and trees will hold more compost, more fertilizers, and more water, so in theory, less looking after. A good rule of thumb for trees is that for every centrimetre of tree width, add an extra 30cm for the height and width of the container. For example, a 2cm in diameter trunk would require the container to have a width of 60cm and a height of 60cm. This is quite a large container but is necessary in order for a tree in particularly to survive.

What follows is a selected number of shrubs and trees that can be grown in full sun in containers:

ABUTILON (Flowering Maple) ‘Nabob’

This large evergreen shrub produces maple-like leaves, with bowl-shaped, deep crimson flowers.  Abutilon grows up to 3m high and best grown in soil based compost, with bamboo cane supports, it needs protection from frosts.

ACER PALMATUM ‘Bloodgood’

This tree has dark reddish- purple, maple-like leaves that turn bright red in autumn. This tree, therefore, has an interest in spring to autumn. It flowers in spring, where small, purple blooms are followed by red fruits.

As it is a tree it will need a very large container of soil-based compost. As with all trees in containers, it requires plenty of water, especially in its first growing year. Acer will grow up to 5m tall.

ARGYRANTHEMUM FOENICULACEUM(Marguerite)

This small subshrub evergreen has ferny, silvery-grey foliage and white flower with yellow centres, from summer to early autumn. It will need a large container of multipurpose compost. It is not hardy and so will need some protection from the Frost. The subshrub can grow up to 80cm tall.

BUXUS SEMPERVIRENS (BOX) ‘Suffruticosa’

This small evergreen shrub favoured by many topiarists forms a dense mass of oval green leaves. It will thrive if it planted in a large container full of multipurpose compost. It can be shaped once the shrub has established.  This box is quite a large shrub and can grow up to a 1m high.

CESTRUM ELEGANS

This large tender shrub that has large, spear-shaped light green leaves. During summer, it produces dense clusters of scented, tubular pink/red flowers. Cestrum can grow up to 3m in height and best grown in large containers. As it is a tender plant it will require protection from severe frosts.

CHOISYA TERNATA (Mexican Orange Blossom)

This large evergreen shrub can grow up to 2.5m tall and tends to grow in a round form. The oval-shaped leaves are aromatic, glossy and bright green when old, but light golden when young shoots emerge. Choisya can produce two sets of fragrant, white flowers, in late spring and early autumn.

CORDYLINE AUSTRALIS (Cabbage Palm)

This small evergreen tree has a fountain of spiky, purple leaves, and this stands out from the usual specimens found in container gardens. The tree will benefit by being grown in a tall container, full of soils based compost. For a tree it is unusually short, standing at 3m high when fully grown. Cabbage palm is not fully hardy and so will benefit from some frost protection.

FELICIA AMELLOIDES (Blue Marguerite)

This blue counterpart of the Marguerite is usually grown as an annual, but it is, in fact, a subshrub grown for its dark leaves and masses of yellow centred blue flowers. They flower from summer to autumn. Felicia only grows to 25cm high and so can be grown in pots, window boxes, and hanging baskets.

FATSIA JAPONICA (Castor Oil Plant)

This 2m high evergreen shrub with large dark green, glossy, hand-shaped leaves, and small white spherical flowers in autumn. This is followed by black berry-like fruits. As they produce a display in winter then it will add interest during that time frame. Fatsia needs to be grown in a large container full of soil-based compost.

FUCHSIA ‘Mrs Popple’

This small shrub with its deciduous, dark green leaves and single, red and purple flowers in summers. It does make a great statement in a large container of soil-based compost. This fuchsia grows to around 1m high but does require some shelter in winter.

HEBE ‘Ruby Edge’

Another small evergreen shrub that has oval bluish- green leaves with red margins. In summer, they produce a pale white/mauve flowers. The shrub grows to 45cm tall and prefers a soil based compost. Hebe should be placed in a position that will shelter it from strong winds and frosts. To keep it compact, trim after flowering.

LAVANDULA STOECHAS (French Lavender)

This popular evergreen shrub of grey-green aromatic foliage. It flowers from late spring to summer of scented, blue or white flowers. Lavender only grows to 45m tall and would prefer a free-flowing multipurpose compost, mixed with sand.

MAHOLIA AQUILFOLIUM (Oregon Grape)

This sweet smelling small evergreen shrub with dark green, spiky, foliage. In spring, it produces clusters of tiny yellow, sweet-smelling flowers, followed by bluish-black berries. The plant is very attractive to look at all year round, but be aware as the leaves are very sharp! Maholia plant grows to 1m tall and would appreciate being grown in a large pot full of soils based compost.

PICEA ABIES ‘Ohlendorffii’

This is a small, bushy conifer, with tightly spaced, short green needles. It grows slowly and tends to grow to around shape as it matures. The final height of this conifer is 1m high when planted in a large container filled with soil-based compost. Picea does not appreciate being dry at the roots at any time, so may need frequent watering.

PIERIS JAPONICA (Lily of the Valley Bush)

This medium-sized shrub, with leathery, elongated leaves. The young leaves tend to be red in colour in spring, soon turning green later on the growing season. They flower in spring, where they produce clusters of lily of the valley type flowers, which are either white, pink or red.  Pieris need to be grown in a large pot of ericaceous compost, where it will grow up to 2m tall.

PINUS MUGO (Dwarf Mountain Pine) ‘Mops’

This compact evergreen conifer forms a real dense mound of needle-like, green leaves. It, therefore, provides a point of interest throughout the year. Prefers to be grown in a large container of soil based compost, where it will grow to 1m high.

RHODODENDRON YAKUSHIMANUM

Of all rhododendrons that can be grown, this is the most suitable to grow in containers. It is dome-shaped, evergreen, with dark green leaves. It flowers in late spring where funnel-shaped, pink to white blooms are produced. Needs to be grown in ericaceous compost, where it will grow up to 2m tall.

CONCLUSIONS

In this article, growing plants in containers in full sun has been discussed, in particular what variety of trees and shrubs are suitable in these growing conditions.

A variety of shrubs and trees of different leaf colours has been shown. Some shrubs look beautiful, and some have the extra added bonus of being highly scented. All these plants highlighted should bring a point of interest throughout the year. There is a shrub or tree for you.

As ever, if you have any questions or comments, please feel free to use the comment box below.

Thank you