I wrote this letter to a friend and thought it was a good one to share for those of you just starting out.
It's great that you are trying to grow more food! I have lots of books you can borrow if you'd like. I'm still a learning a lot from my experience of growing food, to maximize our small garden. I think as a gardener, I will always be a student, nature is a tough teacher!
The first and most important thing about growing healthy plants organically, is to nurture the soil. If the soil contains all the nutrients needed for the plant to thrive, insects and disease stay away. Some people even spray nutrients on plants in the form of compost "teas". I compost all non-diseased plants from the garden and from kitchen scraps so that I recycle most of the nutrients back into the soil that way. We even compost tree trimmings as well. If the plant is diseased you should discard the plant matter, or "cook" it until the fungi or insects die off. "Cooking" it under a black tarp on a hot summer day would do the trick.
ATTRA is a great website about growing organically:
Sunlight is crucial to most garden veggies. Lettuce and cilantro actually prefer light shade, esp in the warmer months. Full sun will give you the best results for most everything else.
Watering is another key factor in keeping your plants healthy. Since we're in an arid zone, I try to mulch my plants with grass clippings or unfinished compost to keep the soil moist and save on the water bill as well. Too much water can cause disease such as damping off, or root rot. Some plants need more water than others, it's a matter of learning through experience too.
In terms of disease an insect control, crop rotation is a good way to avoid them as much as possible, but bugs and fungi still happen. "Path To Freedom" website folks have been growing tons(literally) of food for decades and they say the bugs have been attacking in much larger numbers more recently because of the fluctuations in weather from Climate Change. I try to pick bugs off and put them in soap water.
For fungi, I did come up with a good safe mixture to spray for fungi that is prevalent in the cucurbit family(zucchini, cucumbers, melons and pumpkins)
Here's the recipe for it:
Choosing what to grow for which season is important. I discovered that the hard way this year, by trying to grow kale in the summer.(My Mom insisted we eat Kale all year long) Kale and other brassicas (broccoli, cabbage, brussel sprouts, nappa cabbage, daikon radishes) likes cool/cold weather, and summer was harsh for it. The kale ended up being attacked by harlequin bugs and we ended up just digging it out without much harvest. I can lend you some books if you like. The books are written mostly for shorter climate zones so we have to wing it sometimes here in SoCal. The books talk about growing one crop/season in the bed, then rotating the following year. For us, we have such a long growing season, that we can grow about 3 different crops in the same bed. That where it gets tricky, and I'm still learning the process.
To maximize growing as much food as we can is a logistical juggling project, we have to have the next crop growing and ready to transplant once the old crop is finished. I often get too busy juggling freelance work for the studios that I don't have everything growing at the right time. We also have to think about which plants not to plant there next:(same botanical families will be affected by disease). For example, if you are growing tomatoes in one bed, don't plant eggplants, potatoes or peppers there right after it because they are in the same family. Learning which veggies belong to which family helps tremendously.
Learning the veggie family also helps with their feeding "personalities". Brassicas, Cucurbits, Lettuces and Nightshades(tomatoes etc) are very heavy feeders that require a lot of nitrogen. Then there are the light feeders like Carrots, Yams & Onions. Finally, there are the nitrogen fixers: Legume family which include all types of beans and peas. The Legumes don't like manures or too much nitrogen in the soil, in fact too much makes them sick. The trick is to keep all these guys happy by using their "personalities" to your advantage. The heavy feeders should be grown right after the Nitrogen fixers. Once the heavy feeders have spent most of the nitrogen in the soil, you can grow the Light feeders. Then grow the Nitrogen fixers. That's my crop rotation recipe in a nutshell. Throughout the season, amend any lost nutrients by top dressing the plants roots with compost. If you really want to go all out, rock dust is a very good mineral replacer but do be careful on handling it, as the fine rock dust will be harmful to your lungs.
Just remember, start small then expand as you become successful at the first bed. The more you grow the more you'll learn. I will always be learning. Happy gardening!