If you thought I was pushing the boundaries a bit suggesting we all could grow pineapples then I guess you may not consider bananas as likely candidates either. However they are not actually very difficult to grow and even crop though a little more demanding than pineapples -especially as to headroom.
There are two very good reasons for growing them, other than the sheer fun and delight. Firstly they will have excellent flavour and texture, better than you will ever believe till you do grow them yourself. And secondly -when you do succeed they are an amazingly productive crop for your efforts, in fact bananas are incredibly productive in terms of food value from ground area, even in the UK. Over a hundred delicious, tasty, creamy sweet fruits will ripen on one good plant, each year, more if you are lucky!
Although you could, given the height, grow almost any variety, the dwarf Cavendish or Chinese banana is the easiest (smallest, and quite tough) and the only logical choice. And this is rated one of the finest gourmet choices. It has yellow flesh with a fine texture and taste that makes the 'bought sort' appear as the plastic effigies they are. It is thought to be a variety of Musa acuminata, do not try other Musa species unless you just want the plant not the crop. The red stripe or Abyssinian banana never fruits but produces loads of useful fodder -though what you need to feed banana leaves I'm not sure.
So how do you get your first plant? Well you can't grow these from seed. True you can grow plants but they will either be inedible ornamental varieties or even if edible will when they do crop produce small unpalatable seedy fruits! The dwarf Cavendish or Chinese is often sold in supermarkets for ornamental purposes, but not often identified. You will know it by a faint purple hazing in the central portion of the younger leaves. Get the smallest plant not the biggest as it will undoubtedly be cramped in whatever pot it comes in and the less check it receives the better.
The right sort is also grown in Madeira and the Canaries from where I believe, but do not quote me, you may bring an offset quite legally as long as it is clean of soil or commercially sold to you certified as healthy. ( a banana is herbaceous not a tree and so has offsets just like many ornamentals, orchids and bulbs etc. and is classed with them). Please check the rules are unchanged at Customs. (I also gather they would love to send us these delicious bananas but with our common market they apparently can't as the fruits are allegedly too short and bent). When choosing an offset choose a stout 'leek like bulb' with few leaves yet unfurled. It does not need many or even any roots but the basal plate must be undamaged. Wrap it up really well so it does not get frozen in your suitcase as aircraft holds are unheated.
Once you have your plant or offset then immediately pot it up and keep it warm and somewhere humid and fairly bright. For the first few months it will be compact enough to be a house guest but will soon get huge if you do the job properly. So regular indeed frequent potting up is essential if you are after a decent crop. Plus regular feeding and non stop watering -but never water logging! They do not like wet feet, even so one survived being a marginal on the edge of my pond all last summer but never cropped of course.
Bananas are best grown on to crop in the ground as to do well they need to make a massive root system. This resembles white spaghetti and in good conditions should become almost solid throughout the surrounding soil. Growing to maturity in a large container is possible but will further dwarf a plant and you then lose the head room to the depth of the container unless this is set in a hole. Also the extra constraint seriously reduces the cropping and quality produced. I have taken thirty edible bananas from a plant in a dustbin but it was very well fed, religiously watered and the rootball split the plastic! Any container smaller than a dustbin does not perform at all well especially if the plant is also inadequately fed and watered.
And the hole in the ground needs be big enough to get in! I dig mine extra deep so as to give more headroom and then fill them to within a foot or so with home made garden compost (unsieved; as it comes, if you buy in then mix a bag of John Innes no3 with one of a general purpose and a bag of composted coarse chopped bark). I did place soil warming cables in place first but have not needed them as I keep the whole tunnel heated -in a smaller construction such may be necessary as the soil loses heat sideways. The top is more sensitive to cold than the roots are and is easily damaged by frost.
Indeed just low temperatures above freezing can damage the crop as yet hidden within the plant if they persist. However bananas survive and crop as long as they are kept a little warmer than say citrus but they do not need really tropical heat, 20 degrees centigrade is more than enough. My double walled polythene tunnel (see KG Jan 2000) is heated by two thermostatted 1Kw bathroom fan heaters -which also move the air on hot summer days. They do run most of the night in winter (on economy seven of course) but as soon as the sun comes out they cut off and are rarely working much from late spring till late autumn.
It is possible to straw and wrap the plant and for it to get through the average winter without heat but then you check the plant and the crop is always smaller, and later. For the best crops constant unchecked growth is essential so the warmer and brighter the better through winter. (In most summers they are happy staying under cover and find outdoors too cool except in exceptional years, and the wind shreds their tender leaves.) Adding extra light (in the afternoon extending the day length to twelve hours) with a proper grow lamp significantly improves their performance but is not necessary.
Banana plants do get tall, even the dwarf ones, so the usual greenhouse or small conservatory is not really big enough. Ideally you need three metres or ten feet of head room and half as much clear each way. Sufficient room allows the leaves to push up and open out naturally. You can grow them with less room but then you may need to aid the leaves to unfurl and to get them into position. My eight and a half foot high plastic tunnel works well as the shape helps the leaves slip and find their right place whereas a glass roof usually has projections which snag and the panes are easily popped out!
There are few pests and diseases to trouble bananas unless you bring them in with the plant and I've not yet noticed any. I suspect red spider mite may be a problem if they are kept too dry. On warm sunny days they love a misting with clean water and hugely enjoy a seaweed spray. The main care though is just to keep them warm, humid and growing away, if the dead leaves start to mould then keep the air drier and ventilate more. This is also the case when the flowers appear as these may moulder and then threaten the fruit.
Once big and old enough the flower head pops out of the middle of the plant like a giant sweet corn cob, then grows up and over to hang down. The purple sheaths drop away to reveal hands of bananas growing round and pointing back up with each fruit tipped with a whitish cream flower -which does not want pollinating. Once these flowers have withered and died back they are best crumbled off as left on they may mould. You may wish to remove the surplus small fruits and flowers that form after the main crop has 'set'. The difference is obvious and removing the later and smallest fruits makes the rest swell the better as with most crops. Remove small fruits on a hot dry day so the oozing sap dries. You may even cut the whole remaining 'cob' away -this purple cone consists of many many small fruitlets and sheaths and is considered a delicacy in many countries.
Once the first fruits start to yellow then the whole fruiting stem of hands is cut off in one go with a long bit left for a handle and the 'tree' cut down to ground level. The fruiting bunch can then be held in a cool, frost free place if not wanted immediately which will suspend ripening a tad. Or if brought into a warmer place the fruits will ripen, in order, more rapidly especially if enclosed in a large plastic bag -beware of sweating and rotting though.
Your next crop comes from the next 'tree' to mature. The roots will try and throw many extra shoots and these must be removed as a clump will not perform well. As it takes two to three years to grow and crop each stem then at any time you ought to have no more than three stems; say one big, maturing stem, one replacement and a tiny replacement to be. The offsets can of course be potted up for use elsewhere. With skill, and luck, I have had a stem flower and crop every year since I started and now reckon I have had over a thousand fruits in total -which I guess makes me the UKs biggest producer.