watering twice a day in periods of extreme heat is too much of a chore. During the winter, when we assume that plants are looking after themselves more, watering is a task easily forgotten. Just because it has been raining for days on end doesn’t mean our containers are being adequately supplied with moisture. The rain can bounce straight off leafy plants without any water going directly into the pot.
Sometimes, though, containers are unavoidable. If your garden consists of a roof terrace or balcony, then they are the only choice. Pots on either side of the front door or along a terrace are always popular, too. By choosing suitable containers and understanding why certain plants should be avoided, the whole process can be turned into a successful venture.
Selecting suitable containers
The traditional flower pot is a carefully chosen shape, not because of its looks, but because of its practicality. The fact that it is wide at the top, narrow at the base and has smooth straight sides means that however pot-bound a plant becomes, it can always be pulled out. This should be given serious consideration when choosing a pot for your prize specimens.
Although there are some beautifully shaped pots on the market, containers with extravagantly curved sides should be used only as ornaments for the garden. Otherwise, when it is time for the plant to be moved into something larger, the only options are either to smash the pot or to chop off a considerable amount of the plant’s root system.
Whether a pot is plastic, terracotta, ceramic or stainless steel, good drainage is vital. Unless there are really good-sized drainage holes drilled into the bottom, leave it in the shop – it is useless!
Also, bear in mind that the larger the pot, the wider the choice of plants that can be grown in it successfully.
It is interesting to remember that the French king Louis XIV had figured all this out years ago with his famous Versailles pots. They were brilliant designs that enabled plants to be kept in them for decades. Each of their four sides could be removed, which gave his gardeners access to the roots. Every year, one side only was lifted off, any dead roots were cut out and the old compost was gently tweezed out with a specially made implement – something like a small curved fork. This was replaced with fresh compost, which gave the plant a new lease of life. This meant that every four years, all sides of the plant received this treatment, which ensured that the king’s precious Citrus trees remained healthy and in peak condition.
A genuine Versailles planter costs a small fortune, but there are some good replicas on the market. Before you buy, check first that they have removable sides, otherwise they rather miss the point.
ABOVE
Versailles pots with removable sides allow root pruning to be done with ease.
Choosing plants for pots
Seasonal plants such as Canna, Zantedeschia, Agapanthus and Hedychium that die back each year after flowering can all live in pots for years. Once they become too large for their pots, haul them out, divide the clumps into several plants, replant what is required and give the rest away to a gardening chum.
However, the idea of buying a splendid new pot, often at considerable expense, is usually for it to be a permanently planted focal feature, looking attractive all year round, not for just a few months in the summer.
Plants that never get any bigger are ideal. Box (Buxus) balls, bay (Laurus nobilis) lollipops, yew (Taxus) cones and Japanese pom-poms such as Ilex crenata are perfect, as long as they are clipped regularly to keep them in shape. During the growing season, clipping must be done little and often so that the foliage doesn’t become straggly and unkempt. If the foliage is allowed to grow, more stress is put upon the root system as it struggles to support the extra leaves.
ABOVE
Zantedeschia aethiopica ‘Crowborough’ can live in a pot for years if it is well watered.
ABOVE
Japanese topiary such as Ilex crenata are blissfully content in large terracotta pots.
ABOVE
Slow-growing plants like Trochodendron aralioides are happy to spend the first four years of their lives in containers.
For something a little more unusual, try the silver-leaved Corokia x virgata from New Zealand or the dense form of Euonymus japonicus ‘Compactus’.
Another category that contains some interesting choices are those that are very slow-growing and evergreen. There really is little point in choosing anything deciduous: nobody wants to look at a pile of sticks in the winter if the container is in a prominent part of the garden. The Dwarf Fan Palm, Chamaerops humilis, is happy in a pot for years. So is the dwarf Pittosporum tobira ‘Nanum’. This lovely glossy-leaved plant has highly scented flowers in the summer and can be grown in a pot quite easily. Tree ferns such as Dicksonia antarctica are happy enough, too, as their root system takes years to outgrow a large pot. Hebe rakaiensis is another good choice. This plant grows to a 90cm (3ft) mound and then stops, although clipping is still advisable to keep it extra tidy. Consider a rare tree as well: Trochodendron aralioides is slow-growing, tolerant of neglect and essential for any gardener wanting to grow something really unusual.
There is also a wide range of small succulent plants available, all of which are quite content to sit in pots. Try Aloe aristata, Echeveria glauca, Aeonium arboreum and the purple variety Aeonium ‘Schwarzkopf’.
ABOVE
Euonymus japonicus ‘Compactus’ is an unusual leafy choice for a pot.
Finally, there are the strongly architectural spiky plants. Most of these come from desert regions, which mean they have had to adapt to burning hot sun during the day, freezing temperatures at night and long periods of drought, making them admirable choices for containers. Most hardy Yucca suit this purpose for the first few years of their lives, especially Yucca gloriosa and Yucca aloifolia. The wonderfully spherical Dasylirion acrotrichum can live in a pot for years. Probably the most spectacular of all is Agave americana. This plant and its various coloured forms all look stunning in terracotta pots.
ABOVE
Agave parryi and most other desert succulents almost enjoy being in pots.
Compost
With the exception of tree ferns, which require a peaty compost, most plants are blissfully content in a loam-based
