The Potted Garden
There are many people who would like to be able to grow some food plants but do not have a garden or access to an allotment. All is not lost, however, if you have a small back yard or a balcony - even a few square metres of outdoor space is enough to grow a surprising amount of food in pots. Indeed, I remember seeing a gardening programme on television where a person living quite high up in a tower block has filled his balconies with pot plants to such an effect that the area looked more like a woodland garden than the balcony of a high-rise flat!
This leaflet will look at some of the perennial plants that can be grown in pots and tubs to provide food all the year round. Whilst, in theory at least, it is possible to grow most plants in pots, this leaflet will concentrate on the smaller plants that can be grown in restricted spaces, especially those that are very productive even in pots or provide smaller quantities of very nutritious foods. It will only look at those species that are hardy enough to be left outdoors even in the winter - if you are interested in growing less hardy plants that will require some winter protection then please see our leaflet Conservatory Plants. If you are interested in growing the more conventional vegetables in pots then there is an excellent book on the subject. 'The Edible Container Garden' is written by Michael Guerra, published by Simon & Schuster, New York, ISBN 0-684-85461-9.
First, a few observations on growing plants in pots. In our experience it is best to grow most plants in a non-soil based compost. Due to environmental considerations, we do not use peat-based composts nor those that use coir or other tropical products. Instead, we have found several suppliers that produce composts from recycled garden waste. This, in general, gives reasonable results though plants will require supplementary feeding after a few months. A proprietary liquid seaweed feed is ideal for this - if you are more adventurous then you can always make your own liquid feed from materials such as comfrey, nettles or garden weeds. Apply the feed once every one or two weeks throughout the growing season. See our leaflet Vegan Organics - the Basic Principles for more information on this. If you decide to make your own compost mix, then it is important to remember that when fertile garden soil is put into a pot it behaves in quite a different way to when it was in the garden and seldom gives good results. Should you want to use garden soil then there are a number of ways in which you can improve it. Firstly, make sure it contains good quantities of organic matter such as well-rotted leaf mould or garden compost, since this provides plant foods and also acts to hold moisture in the soil. Secondly, add sharp sand or small gravel to improve drainage and allow more air into the compost.
Water, so essential to life, is the main cause of death in pot-grown plants. We often give too much or too little and either can be fatal. Unless stated otherwise in the text, all the plants listed here have average water requirements. This means that they need considerably more in their growing season and only enough to keep the soil moist in the winter or when they are dormant. In general, do not water a plant until it is nearly dry, but water it before it is completely dry. Be generous in the summer, but be a scrooge in the winter. In the summer it is best to water either in the early morning or late afternoon when the sun is not so hot, but in the winter try to water in the late morning to allow the foliage to dry off before the evening. It is important to remember that in very cold weather in the winter plants can die of drought simply because the soil is frozen and so there is no free water available. In periods of prolonged cold weather it is advisable to give the pots some protection, either by burying them to their tops in the soil or by wrapping insulating material around them.
Whereas, conventionally, it is usual to grow just one plant in a pot, this is not the only possibility. Indeed, if you wish to follow permaculture practices then you will be looking for ways to grow a number of plants together. One way we have found this to work is by using old bath tubs (these can be made to look quite pretty by putting them into a wooden frame or something similar). You need to seal off the plug hole (since you do not want to have water pouring all over the floor) and then put a layer of grit about 75 - 100mm deep in the bottom of the bath to ensure good drainage. Fill the bath up with good quality compost to within 50mm of the top and then plant out. It is possible to get quite a few plants into each of these baths, especially if you understand basic permaculture principles and ensure you utilize all possible strata. Thus you could have a small tree planted in the centre with smaller shrubs planted around it. Underneath the shrubs you could grow herbaceous perennials and bulbs with, perhaps, a not too vigorous climbing plant trained into the tree. With careful selection of compatible species it should be possible to grow quite a number of plants in the tub. There are additional benefits to growing more than one species in a container. Many plants, such as peas and beans, can enrich the soil of the pot with nitrogen, whilst other plants, such as the onions, can help to prevent infestations of pests or diseases.
Most of the plants listed below prefer a well-drained near neutral soil and a sunny position. Those that require different conditions will be noted in the text.
Bulbs are generally very suitable for pot cultivation and can often be grown outdoors for much of the year, being brought in for their ornamental value when flowering. Many bulbous species do require a period of dormancy after flowering and will usually be best kept rather on the dry side at this time in order to prevent rotting.
Allium species. All members of this genus of ONIONS and GARLICS produce more or less edible leaves, flowers and bulbs, with many that are both very tasty and ornamental. Indeed, this is such a useful genus that we have produced a leaflet of the more productive species (see Allium Species - the Perennial Onions). The following are some of our more favourite species. They all grow up to 30cm tall, producing clumps that can be 30cm or more in diameter:-
- Allium cepa. Whilst I would probably not bother to grow the commonly cultivated ONION in a pot, there are several perennial forms that are of interest. For example, the EVERLASTING ONION (Allium cepa 'Perutile') produces a clump of growth much like CHIVES (Allium schoenoprasum). Much hardier than chives, it is evergreen and continues to provide edible onion-flavoured leaves all through the winter. The TREE ONION (Allium cepa proliferum) produces small bulbs instead of flowers at the top of its flowering stem. These bulbs have a very strong flavour, ideal in salads and as a flavouring in cooked dishes.
- Allium cernuum. The NODDING ONION is one of my favourites. Not only is it beautiful to look at when in flower, both the flowers and the leaves have a very nice onion flavour. The flowers look especially attractive when used to decorate salads.
- Allium fistulosum. The WELSH ONION has the same growth habit of chives, forming a gradually expanding clump of onion flavoured leaves that can be harvested for much of the year.
- Allium moly. The GOLDEN GARLIC produces bright yellow flowers in late spring. These have a delightful sweetness that is quickly followed by a moderately strong garlic flavour. The leaves can also be eaten in the spring and the small bulbs used as a garlic substitute.
- Allium neapolitanum. The DAFFODIL GARLIC produces edible leaves from late autumn until the spring followed by white flowers in mid to late spring. These flowers are especially sweet at first, followed by a mild garlic flavour. The small bulbs can be eaten raw or used as a mild garlic flavouring in cooked dishes.
- Allium sativum. GARLIC grows very well in pots, as does the more interesting SERPENT GARLIC (Allium sativum ophioscorodon). This form produces small garlic bulbs instead of flowers, but the flowering stem has no sense of direction and frequently loops the loop on its way up! Both the small bulbs and the main bulbs can be used in all the same ways as garlic.
- Allium schoenoprasum. CHIVES are one of the easiest of crops to grow in pots and can provide edible leaves for much of the year.
- Allium tuberosum. GARLIC CHIVES are becoming increasingly popular in the West. The leaves are delightfully tender and can be used raw or cooked. The white flowers, produced in late summer and early autumn, have a lovely sweet flavour followed by the onion taste. They make an ideal addition to salads or can be eaten on their own. Garlic chives respond well to bringing indoors in the winter and will continue to grow quite happily in a warm kitchen.
Camassia quamash. The QUAMASH was a favourite root crop of the native North American Indians. Growing 30 - 50cm tall and producing a spike of blue flowers in the spring that, from a distance looks a little like bluebells, this is a very attractive plant to grow. The bulbs are harvested once the plant has died down in early summer, they usually divide well and so there can be a crop for eating and bulbs for growing on. The bulbs are best baked, when they develop a very pleasant sweetness and they can be used as a staple food like potatoes.
Lilium lancifolium. Whilst grown as an ornamental plant in the West, the TIGER LILY is cultivated as a food crop in the Orient, where they will often prevent the plants from flowering in order to obtain the largest bulbs. These bulbs have a slight bitterness to them, but are a very acceptable meal when baked. The bulbs of all other members of this genus are also, at least in theory, edible, though several are too bitter to make them worthwhile. Others that have been specially mentioned for their eating qualities include Lilium auratum, L. bulbiferum, L. canadense and L. columbianum.
Oxalis tetraphylla. This species, as now recognised by botanists, includes the IRON CROSS PLANT which was formerly known as O. deppei. This very easily grown small plant will produce a fountain of leaves from mid spring to late autumn, with small red flowers for much of this time. Both the leaves and the flowers have a refreshing lemony flavour and make very tasty additions to the salad bowl. Children are especially fond of this plant, my young ones are so keen on the flowers that there is seldom one to be seen open in our garden. The flowers and leaves of all other members of this genus can also be eaten. One small word of warning about this and many other plants that have a lemon-like flavour. The flavour is produced by oxalic acid - this substance should not be eaten in large quantities since it can bind up certain nutrients in the diet, particularly calcium. It is also best avoided by people with rheumatic complaints since it can aggravate their condition.
Generally rather larger than the bulbs, especially in their root systems. Unless you divide them every year (which is probably a very good idea for many of the species here), you are going to need to use pots at least 12cm in diameter.
Agastache foeniculum. ANISE HYSSOP can grow up to 1 metre tall and 30cm wide. It produces spikes of small blue flowers in the summer which will pull in bees and butterflies from miles around. Both the leaves and the flowers have a delightfully sweet flavour somewhat like liquorice and can be used raw in salads etc, or as a flavouring in cooked dishes. This is another of those plants that my children simply will not stop eating!
Bunias orientalis. TURKISH ROCKET grows up to 1 metre tall and 50cm wide, producing masses of small yellow flowers in late spring. A member of the cabbage family, the leaves have a cabbage-radish flavour and can be used in late winter and early spring, then again in the summer, as a cooked green or in salads. Whilst many people like them, I find the taste a bit too strong and the texture less than wonderful. What I do really like about the plant, though, is the flowering shoots. These can be picked over a period of about six weeks in late spring and early summer and used like sprouting broccoli. Whilst they are a lot smaller, I find the taste to be superior.
Campanula species. All members of this very ornamental genus are edible, with some of them providing deliciously flavoured leaves and flowers for the salad bowl. Amongst my favourites are:-
- Campanula persicifolia. This evergreen grows 1 metre or more tall and spreads at the roots to form clumps 1 metre or more across. The leaves are rather small and thin, but have a pleasant sweetness. The bell-shaped flowers are borne on tall stems from early to late summer, they can be white or blue and have a pleasant mild flavour with a slight sweetness. They look very beautiful in a salad bowl.
- Campanula portenschlagiana. This is a very vigorous low-growing species that can even root into old brick walls - indeed I have seen it growing up the side of an old church reaching right up to the top of the spire. An evergreen plant, the mild flavoured but rather chewy leaves can be eaten all year round, whilst the flowers are produced in late spring and early summer.
- Campanula poscharskyana. Somewhat similar to the preceding species, but with larger leaves and a slightly taller habit. We find the leaves slightly more acceptable in the salad bowl.
- Campanula takesimana. The KOREAN BELLFLOWER grows about 60cm tall and can spread quite freely at the roots. The young leaves in spring have a taste very similar to cos lettuce whilst the beautiful flowers (just look inside the floral tube to see the markings) have a very mild flavour.
- Campanula versicolor. Growing up to 1.2 metres tall, this has to be one of the tastiest leaves that can be grown - and it is available all winter! The flavour is very much like the sweetness of fresh garden peas and the flowers, which are produced from mid summer until late autumn, are if anything even sweeter.
Chamaemelum nobile. Growing no more than a few centimetres high, the non-flowering cultivar 'Treneague' is an ideal ground cover plant for growing in pots. Whilst I would certainly not class it as a productive food, when grown with bulbous species such as the lilies or quamash it will help to keep the plants healthy and free from disease.
Chenopodium bonus-henricus. GOOD KING HENRY grows to a height and width of about 30cm. The leaves and young shots are often cooked as a greens, though I find them a little bitter. The seeds are rather small but they are very nutritious and can be eaten like rice. Make sure you wash them thoroughly beforehand to remove a bitter substance from their seedcoats.
Claytonia species. There are two main species of interest here, MINER'S LETTUCE, C. perfoliata and PINK PURSLANE, C. sibirica. Both grow about 20cm tall and were formerly included in the genus Montia but are no longer considered to be distinct enough to warrant such status. Whilst both are short-lived, they usually self-sow freely and maintain themselves very well in pot cultivation. Unlike most of the plants here, they will grow much better in shady conditions, even in quite deep shade. The leaves, which can be harvested all year round, have a somewhat earthy flavour reminiscent of raw beetroot.
Cornus canadensis. The CREEPING DOGWOOD grows about 25cm tall and spreads at the roots to form quite extensive groundcover. The plant flowers in late spring and then produces bright red fruits about 6mm in diameter in late summer. These fruits have a very mild flavour but are very rich in pectin, a substance well known to jam makers who use it to make the jam set. Pectin also has many important protective roles to play in the body and so is a very healthful addition to the diet.
Eruca sylvestris. This is a genuinely perennial form of SALAD ROCKET, with an almost identical though perhaps slightly stronger flavour. It grows about 30cm tall sending out short-lived woody branches each year from a central stem. The leaves are used mainly as an ingredient of mixed salads, though the flavour is too much for me.
Fragaria vesca 'Semperflorens'. The ALPINE STRAWBERRY, which grows up to 40cm tall, is very productive in a pot, supplying its exquisite fruit from late spring until late autumn. Whilst much smaller than the cultivated strawberries, the flavour is far superior. If you want to grow the conventional STRAWBERRIES (Fragaria x ananassa) then these also do well in pots.
Malva species. All members of this genus provide mild-flavoured edible leaves that can be used like lettuce in salads. The two I would prefer for pot cultivation are M. alcea, which can grow up to 1.2 metres tall and 75cm wide, and the MUSK MALLOW, M. moschata, which is somewhat small growing up to 80cm tall. The leaves can be harvested from late spring until the plants come into flower in the summer. Then harvest the leaves and use them in salads (the flavour is very similar), finally cutting the plants down when flowering is almost over in order to obtain more leaves in late summer.
Melissa officinalis. LEMON BALM grows about 75cm tall and 40cm wide. The young leaves, which are available from mid spring until the autumn if you cut the plant down when it flowers, have a very pleasant lemon flavour, making a nice addition to salads.
Oxalis tuberosa. OCA is a staple root crop in South America and it can crop very well in this country - especially if grown in a pot. You need a pot at least 25cm in diameter and 20cm deep to get a good crop. Plant the tubers in mid April about 4cm below soil level and just leave them to grow. Come the autumn, give the plants some protection from frosts until at least the end of October because the roots do not even start to form until late September. If you grow your plants well you could end up with 1 kilo or more of edible tubers - these have a distinctive lemony flavour when first harvested but become sweet enough to eat raw once they have been exposed to the light for a week or so.
Peltaria alliacea. GARLIC CRESS is a very vigorous plant, growing up to 1 metre tall and spreading swiftly at the roots to form a dense evergreen ground cover. The leaves have a strong flavour somewhat like a cross between garlic and cress (hence the common name) and can be harvested all year round though are best in the winter when they are milder. We find them too strong to use in any more than small quantities in salads and cooked dishes, though we have met people who eat the leaves as though they were lettuce!
Reichardia picroides. FRENCH SCORZONERA is somewhat similar in appearance to DANDELIONS (Taraxacum officinale), though the similarity does not extend to the flavour. Unlike the bitter-tasting dandelion, French scorzonera has very pleasant mild-flavoured leaves that can be used like lettuce in salads. The plant does very well in pots and can provide edible leaves all year round if it is harvested regularly to prevent flowering and given a bit of protection in the winter. An added bonus, this is one of the very few plants that we have found to be immune to the predations of slugs and snails.
Rumex species. The SORRELS have acid, lemon-flavoured leaves beloved of children and all those adults who still like a sharp flavour. They make a tangy addition to salads and can also be cooked like spinach. The two species we most commonly grow in pots are the POLISH SORREL (a variety of R. acetosa) and the FRENCH BUCKLER LEAVED SORREL, R. scutatus. The Polish sorrel is a very superior form, it rarely flowers concentrating instead on providing an abundance of large leaves for most of the year. The plant grows about 30cm tall and forms a slowly growing clump. The FRENCH BUCKLER LEAVED SORREL is a lower growing plant with much smaller leaves. It spreads quite vigorously at the roots and will need to be divided annually to keep it within bounds.
Viola odorata. The SWEET VIOLET is an evergreen plant that grows only 15cm tall but spreads vigorously at the roots to make an excellent ground cover. It flowers in the winter and early spring, producing delightfully scented blue or white flowers. The leaves can be used all year round in salads, but have very little flavour. The flowers, however, are something else. They have a strong, sweet taste rather like the parma violet sweets of my childhood (no surprises here since they were traditionally used to make this sweet). As well as being a very decorative addition to a salad bowl, the flowers are also one of the tastiest.
Deciduous Shrubs and Small Trees
This is a list of mainly shrubs, though a few smaller trees are also included for people with a bit of space for larger pots, and who would like to experiment with a woodland garden in a container.
Amelanchier species. The JUNEBERRIES are very ornamental shrubs with their masses of white flowers in the spring and attractive autumn colours. They also produce very tasty blackcurrant-size fruits in early summer - this fruit is soft and juicy with a sweet flavour that has a hint of apple. It is absolutely adored by children. There are many species in the genus. A. alnifolia is one of the smallest, growing about 2 metres tall, and also has perhaps the best quality fruit. A. humilis and A. spicata are two other of the smaller species whilst the somewhat larger A. stolonifera, which suckers freely, is my personal favourite for taste and quality of fruit.
Chaenomeles species. There are two small species of garden QUINCE, plus a number of hybrids and literally hundreds of garden cultivars. The plants do very well in pots, tolerating quite severe neglect yet still flowering for much of the winter and spring before producing lemon-sized yellow fruits in the late autumn. These fruits are too harsh to eat raw, but make an excellent pie with apples or can be made into jellies and jams. C. japonica grows to about 1 metre in height whilst C. speciosa can be somewhat larger, though both can be pruned to keep them within bounds. The various cultivars of the hybrid C. x superba are particularly well suited for pot cultivation.
Crataegus species. The HAWTHORNS are a sadly neglected fruit - sad for me at least since they are perhaps my favourite fruit that can be grown in the temperate zone. Unlike the rather boring fruits of our native species, there are several species, particularly from N. America and China, with very tasty cherry-size fruits that ripen in the autumn. If you want to grow the plants in pots there are two different strategies you can adopt. Firstly, it is possible to grow some of the smaller trees such as C. arnoldiana and C. illinoiensis in the form of an umbrella. You simply remove any side branches from the bottom 1.5 - 1.8 metres of trunk as the tree grows and then allow it to develop a crown above this height. Even when quite mature, it will grow and fruit quite happily in a pot 45cm diameter so long as you do not forget to water it too often! Alternatively, there are a few small shrubby species, such as C. baroussana, which only reach a height of about 2 metres. See our leaflet Crataegus Species - The Hawthorns for more information on this wonderful genus.
Fuchsia species. All members of this genus, including the thousands of ornamental cultivars that have been developed, have edible fruits, though you probably would not want to eat them all since many have a distinctive aftertaste. Nevertheless, there are many very tasty species and cultivars that are hardy. The best way to find a form you like is to taste the fruits of plants you find growing (get the permission of the owner first though!). Those that we like include 'Doctor Foster', 'Empress of Prussia', 'Phyllis', 'President Roosevelt' and 'Schönbrunner Schuljubiläum' which all have heavy crops of larger than average fruits.
Hibiscus syriacus. This is a beautiful shrub made all the more valuable in the garden by its habit of flowering in the autumn when the quantity of flowers in the garden is well on the wane. The flowers can be 8cm or more in diameter and many attractively marked forms have been developed. The plant grows up to 3 metres tall, but is very amenable to pruning and so can be kept much smaller. The young leaves have a pleasant nutty flavour and can be eaten in salads. The flowers are very mild in flavour and can be used as an amazingly attractive lettuce in salads.
Malus domestica. The common APPLE grows very well in a pot so long as it is on a dwarfing rootstock such as MM27. It is generally necessary to grow more than one different cultivar to ensure cross pollination and a good set of fruit.
Prunus persica. Whilst the PEACH is too large for pot cultivation, a number of genetic dwarfs have been produced over the past few years that are particularly suitable for growing in pots. The shoots only grow about 10 - 15cm each year, but they are crowded with leaves, flower buds and potential fruits. 'Bonanza' and 'Nectarella' are particularly good forms and, although the plants are dwarves, the fruit is normal sized and well flavoured.
Ribes species. The CURRANTS and GOOSEBERRIES can fruit very well when grown in pots. Perhaps the GOOSEBERRIES, R. uva-crispa, are the most suitable though REDCURRANTS (R. rubrum and R. warszewiczii) do almost as well. The JOSTABERRY, R. x culverwellii, is also suitable whilst the BLACKCURRANT is somewhat more vigorous and will require a much larger pot to do well.
Vaccinium species. BLUEBERRIES need a lime-free potting compost, otherwise they are very easy subjects for pot cultivation and can fruit very well. The fruit is pleasantly sweet and juicy, though the flavour can be variable. The most commonly cultivated species in Britain is V. corymbosum, and several selected cultivars are available.
Another member of the genus of special interest for its fruit is the KAMCHATKA BILBERRY, V. praestans. This is a dwarf shrub, no more than 15cm tall and making clumps up to 50cm wide. The fruit, which is about 12mm in diameter, has a delicious sweet and fragrant flavour, somewhat like a strawberry.
Evergreen Shrubs and Small Trees
Much the same notes can be made about the evergreen shrubs as the deciduous ones, with one important addition. Pot grown evergreen plants are much more susceptible to damage by drought in the winter when cold weather can make free water unavailable to the plants. It is very important in cold weather to protect the pots and prevent the soil in them from freezing solid.
Arbutus unedo. There are dwarf forms of the STRAWBERRY TREE, such as 'Compacta' or 'Croomei' that only grow about 2 metres tall and so are suitable for pot cultivation. This is a very ornamental tree, especially in the late autumn when its white bell-shaped flowers and large red fruits produced from the previous years flowers are both on the tree. Whilst many people are not strongly attracted to the fruit, I find its sweet flavour and soft texture very acceptable.
Gaultheria procumbens. The CHECKERBERRY requires a lime-free compost but otherwise it is a simple plant to grow in pots, growing best in shady conditions. It reaches a height of about 15cm, spreading at the roots to eventually form quite large clumps. It produces bright red berries in the autumn that usually hang on the plant all winter. The flavour is somewhat unique and, if you like the smell of hospital waiting rooms, then this one is for you since most people find it reminds them of germolene. Surprisingly, many people do enjoy having a nibble on it and find it worthwhile growing since it is likely to be the only fresh fruit you can pick from your garden in the winter and early spring.
Mahonia aquifolium. The OREGON GRAPE is one of those foolproof shrubs that is almost harder to kill than to keep alive. It survives in most soils and situations, even in very poor light. It is an ideal plant for a dark back yard with hardly any sunlight and will repay you with golden yellow flowers in the winter followed by dark blue berries in the late summer. These berries have a rather acid flavour, the kids usually love it but many adults will prefer to use it as jam etc. Two other dwarf species also do well, M. humilis and M. pumila.
Myrteola nummularia. This dwarf evergreen shrub grows no more than 10cm tall, spreading to form clumps 50cm or more in diameter and making a reasonable ground cover through which bulbs grow well. It produces a delicious fruit up to 1cm in diameter in late autumn and early winter. The fruit has a soft juicy flesh and a delicious slightly aromatic flavour - it is one of those foods that you never seem to get enough of. The plant is not fully hardy away from the south and west of Britain and may need to be taken into a greenhouse for the winter.
Rubus nepalensis. The HIMALAYAN RASPBERRY grows no more than 10cm high, but it sends out vigorous shoots along the surface that root into the soil and soon create an effective ground cover. The fruit, produced in the summer, is like a slightly smaller version of the raspberry. The flavour is a bit more acid, but very acceptable.
Whilst it is possible to grow the smaller climbing plants into supports in the pot, or perhaps a small shrub or tree, it is also possible to train the climber onto a wall of a house or other structure. It is surprising just what sort of area a well-grown climber in a pot can cover.
Amphicarpaea bracteata. The HOG PEANUT is a herbaceous climbing plant, twining around small shrubs for support. It belongs to the pea and bean family and, like most members of that family, enriches the soil with nitrogen and so helps to feed other plants growing nearby. The seeds, which are rather larger than lentils, can be eaten raw like peanuts and have a pleasant bean-like flavour. Like the related peanut, the plant buries its developing seeds into the surface of the soil.
Apios americana. Similar in growth habit to the hog peanut above, the GROUNDNUT also enriches the soil with nitrogen and produces a very tasty edible root. This root is best eaten baked, when it turns very sweet, and, unlike most roots, it is a very good source of protein with a total content of over 25%.
Passiflora caerulea. The PASSION FLOWER is a very vigorous evergreen climber, capable of clambering 10 metres or more. Given supports to twine around, it will make an excellent job of covering a fairly sunny wall and will repay you with spectacular flowers in the summer followed by lots of yellow fruits containing a small quantity of red flesh in the autumn.
Tropaeolum tuberosum. This herbaceous plant is cultivated in South America as a root crop, but is more commonly grown for ornament in Europe. The plant scrambles to a height of 2 metres, preferring to grow into shrubs or small trees. The large, brightly marked tubers are rather an acquired taste to most Western palates, though they are a staple food in South America. The peppery flavour can be improved somewhat by freezing the tubers after they have been cooked, they are then considered to be a delicacy by many people. We have also noticed an improvement in the flavour if the tubers are harvested after they have been frosted, though if the frost is too heavy they can damage the tubers.
The above list is just a small selection of some of the most interesting edible plants that can be grown outdoors in pots. We cannot currently supply plants but there are plans to get a catalogue running at some time in the future. If you wish to grow any of them and are unsure where to obtain them then we suggest that you obtain a copy of 'The Plant Finder'. This book, published annually by the Royal Horticultural Society, lists over 60,000 plants and the nurseries in Britain that supply them.
The database has more details on these plants: Agastache foeniculum, Allium cepa, Allium cepa proliferum, Allium cernuum, Allium fistulosum, Allium moly, Allium neapolitanum, Allium sativum, Allium sativum ophioscorodon, Allium schoenoprasum, Allium tuberosum, Amphicarpaea bracteata, Apios americana, Arbutus unedo, Bunias orientalis, Camassia quamash, Campanula persicifolia, Campanula portenschlagiana, Campanula poscharskyana, Campanula takesimana, Campanula versicolor, Chamaemelum nobile, Chenopodium bonus-henricus, Cornus canadensis, Fragaria, Fragaria vesca, Fragaria vesca 'Semperflorens', Fragaria x ananassa, Gaultheria procumbens, Hibiscus syriacus, Lilium auratum, Lilium lancifolium, Mahonia aquifolium, Malus domestica, Melissa officinalis, Myrteola nummularia, Oxalis tetraphylla, Oxalis tuberosa, Passiflora caerulea, Peltaria alliacea, Prunus persica, Reichardia picroides, Rubus nepalensis, Taraxacum officinale, Tropaeolum tuberosum, Viola odorata.