Two years ago a Wexford farmer's wife returned to her car in Ferns village to find two suitcases brim-full of marijuana in her boot. Two Chinese men at the scene apologised to her for placing their suitcases in the wrong car (they'd been instructed to stick them in the next car up) The gardai (Irish cops) were called and they tracked the suspects to two houses stuffed floor-to-ceiling with E400,000 worth of wacky baccy plants.
|Don't trust those drug dealers with your car...|
This was one of dozens of busts which have taken place here since 2008, highlighting Ireland’s other "grow your own" boom. Hot housers can produce E100,000 worth of crops every few months from an area the same size of my allotment and back garden (which in contrast make me about E1,200 per year worth of food, though nothing stronger than wild garlic and cayenne chillies.
The secret to the pot houser's success - and also to his downfall - is the 1000 watt grow lamp bulb which gives the cannabis plants the equivalent of twenty four hour blazing sunshine if they so need it. They also bring “heat” on the growers because infrared cameras on police helicopters or the resulting electricity bill spikes are what generally leads to the hot house bust.
But perhaps no one understands the optimum application of light to plants than illicit dope growers who could teach us food growers a thing or three about maximising photosynthesis - the process whereby plants make oxygen and sugar from light, carbon dioxide and water.
Last week I was inspecting some very wacky looking cabbage plants in raised beds that I installed late last year in the side passage of my semi d. The passage, used for channelling wheelie bins in and out, provided me with some excellent extra raised bed space along its permimeter but it gets no more than two hours of direct sunlight daily. Food plants need a minimum of six to do their thing.
|Not as interesting as my side passage, but just as dark..watch out for the Ripper..|
My first step to testing the growing potential for a darker area like this was to stick in a bunch of partial shade tolerant food plants. In went spinach beet, sugar snaps, cabbages and a blackcurrant bush. All did well apart from the cabbages which stretched eerily skyward in search of light and formed no heads at all. So cabbages, and presumably other brassicas like sprouts, broccoli, calabrese and cauliflower won’t work here but sugar snaps and by assocatiation, other legumes like peas and beans, should.
I learned from a Youtube clip, that blackcurrants grow wild in woods and forests and are among the few fruits that can cope with shade or at least dappled sunshine. Mine did fine in two hours of direct sun but would surely have exploded with fruit were it devoid of shade.
Using shaded space is about wastage limitation and most food plots have partially shaded areas where the sun falls only for four or five hours a day. Some have heavy shade like my side passage, where the sun hardly falls at all. Knowing what to do with these spaces is vital to get the most from your ground overall.
|"What? What did he say?" - Some blackcurrants in the dark yesterday...|
Some plants like chillies, aubergines, tomatoes and squashes need more than the minimum six hours of sunshine to do well. Others, like those mentioned above, will produce a reduced amount of food but some food nonetheless. Very few, if any at all, will do well in almost complete shade with less than four hours direct sunlight. Only mushrooms and forced rhubarb can grow in the dark.
The general rule of thumb it seems is that fruits and roots need full sun while those harvested for leaves, buds and stalks can get by with less than the recommended six hours. Good prospects for partial shade (four to six hours) include lettuce, brassicas (in particular cauliflower and broccoli/calabrese), peas, beans, chard, fennell, Jerusalem artichokes, cabbages , mint, kohlrabi, spinach and parsley
|Darkest jungle...forget lettuce/salad...but do check your pants for outsized centipedes|
Those which can apparently cope best of all with the very darkest environs include parsley, chard, spear mint (do contain the roots though) and some darker leaf lettuces.
To increase the level of light in certain areas, we can take some tips from the cannabis growers. They cover their walls in reflective foil so that they get the best exposure for their light sources. Similarly you could surround your plants with reflective surfaces to channel in more light, but a more practical measure is to paint the walls and paths around then in white. White paint in a sunny patio area will also vamp up the light for high light consumers like tomatoes by creating a "sun trap."
In areas where you have deciduous trees it might be an idea to concentrate your efforts on a winter cabbage or broccoli because of course, for many months of the year, the trees won't have any leaves at all and the light will filter through.
|In the dark: "I swear, I saw a lettuce just there..."|
The opposite also applies. When planting in Spring be aware of the potential for increased foliage on trees and shrubs later in the year. I planted Swedes in a raised bed which backed onto my garden fence containing a jasmine and a rose tree. At the height of summer, these generated an overhead canopy of shade which prevented light getting to the swedes at the back of the bed at certain times of the day. The result was healthy big swedes to the front(where the sun hit first) receding in smaller plants to the back (where the sun hit last). As the year went on, the plants at the front grew taller and in turn succeeded in further shading the ones at the back.
|Healthy Swedes to the front...|
No one spot in your garden gets exactly the same light level as another. Even in the same bed, the sun will always reach some plants before it gets to others. In extreme cases with bushy topped plants like Swedes, you may have to consider staggered planting to give those plants most in the shade a head start to prevent their fellows growing quicker and shading them out.
Ideally we should keep all roots like carrots and swedes well away from walls and fences. Use netting for your allotment boundary rather than solid fencing which casts a shadow.
In the future we may all end up with grow lights in our gardens for darker months of the year thanks to new technology. NASA has applied LED technology to plant lighting and this more energy efficient technology is already finding its way into private greenhouses.
LED’s use more than less than half the power required for standard growlights by producing only the light spectrum necessary for plant growth - in this case a red and blue combination. This also means less heat and as it happens, bulbs which can last for many years.
|Blue and red LED on Cannabis (sue me for copyright on the photo i dare you...te he)|
As technology develops it should mean more growing opportunities for gardens in the northern hemisphere, as well as less drug busts - because not surprisingly our cannabis hot housers are already up to speed with LED.