One of the main skills that permaculture requires is using all of our senses to become aware of what the planet is telling us, what is available in abundance and what constitute various limiting factors. Some messages that we can receive are loud, clear and undeniable, others are subtle and there are even occult factors that are hidden either by their miniscule scale or just a lack of or expense of detection tools. How much sun an area gets is usually the first thing that gets considered when we think about planting. Most garden vegetables for instance need to have four to six hours of sun per day, anything less and the plants will be sickly and harvest will be limited. In cases of reduced light, some leafy foods might be able to make their leaves, but if it is a seed or fruit that we are interested in, the plant may never have enough light (energy) to set that fruit or seed, so planting into these areas of limited light would be a relative waste of time. The best feedback loop regarding light availability would be to understand where the sun tracks through the sky, and to visually inspect the path of the sun overhead during the Spring, Summer and Fall to “see” if there are enough hours of direct sun to keep the plants happy.
Too many trees, or buildings blocking what light is available can eliminate the possibility of growing some of the most popular vegetables. Other essential things might be availability of water, soil quality and nutrient availability in the soils. Sure, you may be able to grow your garden hydroponically, in nothing but straw or some other soil-less mix, but some source of nutrients for the growing plants will be essential for their health and ultimately production. Developing a feeling for the organisms that inhabit the growing medium, as well as what they bring to the process, is helpful if not essential to overall success.
How much moisture is available is also a huge part of growing virtually any plant. Too much water and the plant will become limp and the tissues will be soft and lack a thick cuticle (the outer layer of leaves that helps them to resist insect damage) too little and the plant will wither. If either extreme is the rule, or if your location alternately bounces between the two, there are things that can be done to resolve potential problems before they occur. That is why getting to know your site is critical to making your efforts pay off.
I have been gardening since the early seventies in earnest. Even when i was living in apartments, I would have a tiny plot of dirt filled with food , even if it was only a few buckets full of well-drained soil, I would have tomatoes or peas, several bean plants, or lettuces. Over the years, I learned lots of things to help improve the health of my plants, but I also learned some things not to do. Gardening is one of the best hobbies because there is always more to learn and it offers nearly unlimited opportunities to experiment and try new things.
One of the most difficult things that I have had to learn is how to get multiple harvests from limited space. Two years ago was the first time I got triple harvest from the same bit of soil. Initial plantings were peas and cabbage. These two were harvested in a little over two moons. The peas climbed up on a bit of fencing that I rigged over the bed. The cabbages spread wide, protecting the tiny carrot and beet sprouts. These were co-planted, just a few weeks after the peas and cabbages. The root veggies stayed in the soil for most of the spring and summer, but rather than being satisfied with just two harvest times, I also planted cucumbers and squash just before the cabbages came out. The tendrils of which I trained onto the same fencing that held the peas in Spring. The cucumbers were putting out pickling sized “cukes” by mid summer and the squash were covered in blossoms at about the same time, setting fruit before the cool of fall settled in hard. Part of this process was luck, but another part was my own willingness to experiment. I harvested any beet greens that threatened to overshadow the carrots and trained the vines onto the fence which was on the north side of the bed, so that as the sun came in from the south side in fall, there would still be light for the carrots which were putting on mass even after the beets came out.
“Listening” to the plants themselves is the only way to understand what they need and to find ways to keep them happy. The soils are the same. Within them, there can be hundreds of thousands, even millions of organisms, each with their own needs, and requirements for living healthy lives. Filling out the food web that exists underfoot is often able to do more for the plants we seek to grow than any other factor. I have had gardens with limited light and water. I also have had to leave my plants for weeks on end without care of any kind, but because of high levels of organic material in the soil and an intact layer of mulch, protecting my plants, I was still able to get a bountiful harvest. All things being equal, plants can, with love and attention, flourish in spite of certain limiting factors.