Plant Partnership, or Gardening 101
The internet is full of crappy advice about how to grow plants. Like this gem (spat out by ChatGPT when I asked it how it would advise people how to grow plants):
“Caring for plants is like caring for a child. You need patience, love, and a bit of knowledge about what makes them thrive.” ~ ChatGPT and many crappy websites about gardening (which is where ChatGPT learned it from)
Wrong. Plants are not children; and we are not plant parents. We are both partners; plants need us animals, and we need plants. In kitchen gardening we nurture both ourselves and our plants.
Specifically, to thrive and grow plants need five things in the right amounts. Your job is to make sure the plant has enough (and not too much) of these five things.
So what are the five things all plants need?
Water
This keeps the plant standing upright, carries nutrients to all the parts of the plant, and is cracked into oxygen and sugars during photosynthesis. Healthy growing plants do not take up water or feed through their leaves, they do it through the roots. Too much water makes the roots drown and the top parts wilt.
If a plant has too little water, the roots stop working, and the top parts wilt (see the problem there?)
Light
All the green parts of a growing plant, especially the leaves, are like photovoltaic panels. This is where the plant does its magic with photosynthesis. Too much light and the leaves burn (go brown and papery). If the plant gets too little light, it will get smaller and eventually disappear as it scavenges parts of itself to survive. A sign that a seedling isn't getting enough light is 'legginess' where the seedling becomes very long and thin and bends toward the light—if the light is to the side.
Air
The photosynthesising parts of the plant (everything green or red) use carbon dioxide from the air to make oxygen and sugars. The roots use the oxygen component of air (the same as we do). Low airflow around a plant's leaves, along with the resulting high humidity makes them vulnerable to fungal attack. Too much air (wind) and the plant may get damaged leaves and stem.
Temperature
Most plants have a temperature range that they are acclimated to. They can operate somewhat outside this range, (especially if they are chemical-free). Too far above or below the range, however, and they will succumb to cold by going black and then rotting, or die from heat by failing to grow.
Nutrition
For the last 70 years, we have been under the misapprehension that we, the gardeners, must feed our growing plants with chemical fertilisers. These contain the 'macro nutrients:' Nitrogen, Phosphorous, Potassium (NPK). We also had to supply a host of trace elements to deal with mineral deficiencies (these show up as yellow or purple leaves). However, cutting-edge soil science now shows us that we were wrong. Feeding your plants by feeding the soil is cheaper—plant food is recycled animal and plant waste. It is easier—you don't need to worry about dosing rates, mixing chemicals, or whether it is toxic for your pet. And it is better for the planet—chemical fertiliser overuse contributes to algal blooms in lakes and rivers, fish die-offs, ocean dead patches, and excess carbon dioxide in the atmosphere.
The bacteria, fungi and worms and other minibeasts are a food web in the soil. This soil food web gives the plant macro nutrients and mineral trace elements that it can absorb and use immediately. In return, the plant feeds them with sugars. For instance, when a tomato plant is struck by caterpillars, the munched-on leaves send out chemical signals to the surrounding plants and they begin to make their own pesticides even before they are attacked.
Exactly which minerals are passed around in the soil and when is a mystery. I read once that possibly every element in the periodic table is necessary at some point. The symbiosis of plant root systems, and all the soil life actually create topsoil, from the surface down, which brings us to the next point*…
*(The mathematicians amongst us will note that we’ve done our five key things a plant needs, so this next one is ‘extra.’)
Soil
Soil is not dirt, and it is not strictly necessary (hydroponics aeroponics and aquaponics are all growing methods that don’t use it at all). However, healthy soil makes gardening effortless).
Soil is the combination of three different things: rock minerals, organic matter and living soil biota. Rock minerals are the sand silt and clay in soil that has eroded from rocks over millennia. Organic matter is made up of dead plants and animals, poo, poop, sh!t, manure, compost, and decaying mulch. Lastly, the soil biota consists of soil minibeasts, like nematodes, worms, bacteria, and fungi.
Soil is a living thing.
For too long we have treated our soil like dirt. It holds the growing plant upright, yes, but it also provides plant-available nutrients. And it offers them up in the exact quantities and at the exact time that a plant needs them (why? because the plant asks for them—plant-fungi-bacteria communication is an exciting new area of study). Whenever I say, “fertilise,” what I mean is, “add organic matter to feed the soil biology, so they will keep the plant healthy.” “Fertilise” is easier to write.
How do you know if your soil is healthy? It is a dark brown colour, with living creatures visible in every shovel-load, it is moist, and has plants growing in it (even weeds).
That was a pretty intense firehose of information, especially if the concepts were new to you. Do you agree that these are the only five things a plant needs? Did I convince you that this isn’t too complicated? Are you annoyed that I said it was five things, and then gave six? Do you talk to your plants? Tell me in the comments!