What Every Plant Needs
Let's talk about how to grow the plants to get the best results. Plants are alive, just like us. Hard to believe because we don't see them move or breathe. But they do! That's how they are able to grow a little bit bigger everyday. They need the basics : air, water, food, sleep/shelter.
Although you shouldn't have to work too hard to provide your plant with air, sometimes you do need to help them get good circulation. Especially when you are growing things in a greenhouse, the air can get stagnant and impede the drainage of water. When the plants are producing in the field (or backyard), a lack of circulation among the leaves can cause disease, molds, and rot. If you notice this becoming a problem, pruning is particularly helpful. Pruning seems counter intuitive because you are removing limbs, branches, or leaves. But this actually helps the plant to grow better.
You can prune zucchini leaves and indeterminate tomatoes. Peaches especially love circulation and they hate too much humidity so proper pruning is key for perfectly ripe fruit. Some plants (like pumpkins) purposely create a canopy for themselves but they have usually have lots of space underneath their big leaves. Only prune pumpkins in areas that get too overcrowded and are having rot problems.
On the other hand, too much air and wind dries out the soil much faster. The solar panel leaves of a plant are important for soaking in sunlight, but they also keep the soil moist by shading it from things that cause rapid evaporation.
This is probably the most important source of life for plants. Where our bodies are made up of around 60% water, plants are 85-95% water. You can think of it as the plant's blood because it carries nutrients where it needs to go. (Here's some science behind how plants use water) The main point here is to keep the blood flowing! Give your plants water regularly. If the plant doesn't seem to be doing well, maybe it's leaves are curling, first try giving it more water. Then check for other deficiencies, diseases, and pests.
There are a few methods of watering : flood, sprinkle/hose, drip, or rain.
Each plants need certain nutrients that are held in the soil. For example, top heavy plants use more nitrogen, and root heavy crops use more phosphorus. When your own body is short on iron, or calcium, there are health repercussions. But these type of deficiencies in plants are more noticeable since their life span is so short. Common deficiencies include nitrogen, phosphorus, magnesium, zinc, & iron. Here's a great list of the symptoms of each.
You can also find exactly what your soil needs by investing in a $16-40 soil test from BYU. It will break down how much of each nutrient is already present and they will recommend what you should add.
Most people prepare their garden bed(s) every year by spreading and mixing in manure or compost. This is a good general practice, but the important thing here is to make sure its already rotted and broken down. Throwing banana peels and eggshells next to your tomatoes won't give them any nutrients quick enough. You should mix the soil with fresh compost items (like vegetable peels) in the fall to give them enough time to breakdown before spring planting.
If you use manure once a year, pick the right one. Chicken manure is very high in nitrogen and may be too strong some things and can burn root crops, like carrots. However, tomatoes will thrive with heavy nitrogen. Cow manure is the best, overall, balanced mixture. Horse manure can also be used, but doesn't have as much micro nutrition. Green or plant manure is also good, like straw, which should be tilled into the soil in fall so it can break down by spring. Fish emulsions (or fish manure) is a powerful one, it carries more metals and micro nutrition. But it's effect is short-lived. Instead of a big once-a-year application, it does best when you mix it into the water and apply it every 2-4 weeks.
You can also boost your plants throughout the season with side-dressing. You can make a hole next to the base of the plant, and add in a scoop of fertilizer. It takes 2-4 weeks for the plant to find and use the fertilizer, but you'll notice a productive jump when it kicks in. Our favorite things to use are bone meal and blood meal.
Sleep & Shelter
When we talk about plants "sleeping", we're really talking about the amount of light (and resulting heat) they get each day. Plants know what season it is based on the hours of daylight. In the summer they say the days get longer, but they mean the daylight gets longer. The summer solstice in June marks the longest daylight of the year and the winter solstice in December marks the shortest. The difference between the two is 6 hours of daylight! So the plants notice when the sun starts shining less everyday and they get ready for winter.
Most vegetables and fruit need "full-sun". Most sources say this is at least 6 hours of daylight every day, but our field plants get 8-10 hours. These type of plants won't even need shelter unless there are extreme circumstances (heavy wind, hail, frost, etc.). Some plants do enjoy shelter from too much sun, and they call them "partial sun" or "partial shade" plants. Lettuces and greens do great with morning sun and afternoon/evening shade.
With the daylight comes heat. Some plants do not like 100 degree temperatures even with shade and lots of water. They can "bolt" which is when they quickly hurry to produce their seed before they die. It is trying to get the next generation going by flowering and making seeds. Don't be alarmed if this happens to your lettuce or basil or other tender items. Just look for more "bolt-resistant" varieties.