Plants use the sun’s rays to make food through the process of photosynthesis to keep them growing.
Plants that thrive in a high amount of light have adaptations that allow for them to survive. This means 6 – 8 hours of sunlight per day.
They have tough leaves so less water is lost, leaves that are grey coloured will reflect the heat and light, leaves that are smaller and hang straight down will lose less moisture, hairy leaves trap moist air around their leaves.
The benefit of sun is that more food is made which will support more flowers, fruit and healthier roots and cell structure. Most fruit will not develop without sun.
Some plants are adapted to lower light. If these plants had a full days sun they would quickly deteriorate and die out.
These plants have large dark green leaves, are soft in texture and require more moisture to survive.
By having a closer look at a particular plant, you can get clues as to where the plants like to live.
When it comes to edible plants most are very clearly sun loving/needing – they are fruiting plants e.g. tomato, citrus, stone fruit, bananas, cucumber, pumpkin, melons, corn, passionfruit, eggplant etc.
These plants will only produce a small amount of flowers and even less fruit if the sun drops below 6 hours per day. The amount of fruit will correspond to the amount of sun received.
In a spot that only get 3-4 hours of sun per day, there are some edible plants that can perform suitably. These will be the ones that don’t need to make flowers or fruit to eat e.g. lettuce, spinach, rhubarb, rocket, a lot of herbs such as coriander, parsley, chives, cabbage, celery.
In a very shady area that only gets dappled light or an hour a day there are minimal edible plants that will be successful e.g. mint, sorrel, dill chervil, tarragon, vietnamese mint and cardamon.
If you only have shady areas to grow edibles it would help to adjust your expectations. if you want to grow a tomato, there will be some fruit on the bush but it would be greatly diminished compared to the same bush grown in the sun. It may be better to stick to growing the leafy things in this spot.
It would be helpful to give these plants extra feeding i.e., give them worm tea and anything else organic on a weekly basis rather than fortnightly.
Keep a closer eye on bugs or diseases as the plants will be growing more weakly and be susceptible to problems.
Article by Sandra Wilson