How do you make plants grow?
I must emphasise that I am not a gardening expert, and frequently my plants don't grow! However, here are some of my ideas on the subject.
To make plants grow, you have to know what they want. Now, there's an ancient idea which I use as a checklist to see if something obvious is missing or wrong. This idea is the Four Elements, where in past times, people thought that everything was made up of fire, water, earth and air. This is nonsense of course, and we now use "element" in a different way (and there are lots of them!)
However, I've come to think of these elements as things needed to grow plants - obviously vital for humanity once we all stopped being hunter/gatherers and started to grow crops.
It was earth which first caught my eye. It's farmers and gardeners who are interested in earth. Most plants need earth to grow in. There are plants that grow on other plants (such as mistletoe) and plants can grow on or in water. But your average garden plant needs earth to put its roots in. It gets water and nutrients from the earth. We can improve the soil, with compost to improve its structure, and with fertiliser to improve its nutrient supply. We can practise crop rotation - not always growing the same vegetables in the same place - to stop nutrients in the soil being reduced, and to stop a build-up of pests that live in the soil. But apart from what we can do to the soil, it also has a character of its own. It may be acidic or alkaline, and that will affect what you can grow on it. It may be clay or sandy, and that affects how well it holds water (too much for clay soils, and not enough for sandy ones!)
So what can you do about your soil? Finding out whether it's clay or sandy is a good idea, and easy to do. When you wash your hands after gardening, you're washing the soil off. Can you see distinct grains of sand left in the sink? If so, it's sandy. A gardening quote "Clay breaks your back, but sandy breaks your heart". That means that clay soils hare much heavier and harder work to dig, but sandy soils are free-draining, so they dry out quickly, and nutrients (such as fertilise) tend to drain away through out quickly. But I have sandy soil, and I don't find it too much of a problem. You learn to live with your own soil! Acid and alkaline can be testing with a special kit. Most gardens are neutral so that isn't a problem. So quite frankly it's not worth using such a kit, unless you're interested!
It's certainly worth trying to improve your soil. If you're growing greedy plants which take a lot out of the soil, like vegetables, or roses, then adding fertiliser will help. But also adding compost as soil conditioner. Don't use peat for this, please - the peat bogs are being depleted for this, and they are an important natural habitat. Make your own compost, and use that.
Gardeners are obsessed by water! (Or perhaps it's just the gardeners with sandy soil...) It's always the gardeners who complain about long hot spells ("The garden needs the rain!") You can always water the garden, of course. But that takes time, probably a hosepipe (watering cans are seriously hard word for a lot of watering!) and may be against regulations in hot weather anyway, when you need to do it.
There are other things you need to think about with water. In Britain, rain can happen at any time of the year, but summer dries up the water quicker. If you want to plant out, especially something large such as a tree or bush, do it in the spring or autumn after some rain, and the plants can use the water in the soil. You may still have to water it, but not as much.
Another thing to think about is the damp and dry bits in your garden. Shady areas will stay damper. Open areas will dry out quicker. But there may also be dry areas under a tree, because the tree roots take up all the water. A wall can also suck out water from the soil, and evaporate it into the air.
Well, not fire as such (although gardeners often like bonfires, to get rid of woody rubbish!) But fire produces light and heat, both important for plants, and they get this from the sun. So let us think of that as a fire in the sky! Very little grows in the winter, as it's too cold and there is less light. Once the ground warms up in the spring, plants start growing, fast! The date of the last frost is very important, as no tender plant will survive any frost. You don't know when the last frost will be for any year, of course, but you learn the safety point when it's unlikely to occur (beginning of May for me) and you watch weather forecasts carefully. ("I don't care about the daytime temperatures - what are the NIGHTTIME temperature?")
Light is also important. Part of your garden is probably shady. So you go to a garden centre to find a plant that grows in the shade, and they all want full sun. Sigh... (And the ones that say they can grow in the shade often lie.)
There is a relationship between sun and water. Winter is cold and wet, so nothing much grows. Spring is warmer and wet, so things grow well. Summer is hot (we hope!) which is good, but also often dry unless there is a decent amount of rain, as the heat dries the soil out. So summer, which might be considered to be the best time of year, can see a slow-down of growth. Autumn may still be warm, and the soil keeps the heat longer than the air, plus any rain means the ground stays wet longer, which is good for growth. So spring and autumn is often a good time to plant out, as the roots can find water, and the soil is warm enough for growth. You can certainly plant out at other times of year, but spring and autumn are probably best. Lawns grow (and need cutting) in spring and early summer, and then in autumn. They stop growing in summer (too dry and hot) and winter (too cold, even though there's enough water).
The relationship between water and light also affects parts of your garden as well. I've mentioned above that shady areas may be damp - good for growth - but of course they don't have enough light - bad for growth. Open areas have lots of light, but maybe get too dry. On the whole, you can water dry areas, but you can't do anything about shady areas! The worst areas are dry, shady areas, such as under trees. I had one area like this where nothing but dead nettle would grow (but it's an attractive plant, so that's OK).
Plants do need air - carbon dioxide during the day and oxygen during the night. They would die in a vacuum. But I've never seen a garden with a shortage of air! So I've decided that this "element" is not air but space. Plants need space to grow. They don't want other plants stealing their water or nutrients. That's why we weed - to remove the competition for the plants we want to grow. That is why we thin out vegetable seedlings, or transplant or divide up over-grown clumps of plants.
Plants outside have a natural advantage - there's all the earth waiting for them, rain falls from the sy, the sun shines on them, and while they tend to compete for space, some manage to win by themselves! We help them along, but a lot is done for us. Inside, there's more of a problem. I don't have house plants, but I do sow seeds and raise the seedlings on a window sill.
They need soil. You can get soil from your garden, but I must admit that I use potting compost (non-peat if I can get it!) from a garden centre. It holds the water better, they add some nutrients, and it's sterile, so I don't have to remove weed seedlings.
The seedlings need watering, frequently. Various people talk about over-watering, but I've never managed to do this with vegetable seedlings. (I think you can do it with house plants.) But seedlings will die if they dry out too much. The pots are a fixed size, so they can't drive down their roots to find water lower down.
The worst problem I find with plants on window sills is light. Heat is fine - the room will be warmer than outside (and frost-free, we hope!) But inside is much darker than outside. You will see your plants grow towards the light, which is the window. You can deal with this by turning the pots. Then watch the plants change their minds, and grow in a different direction towards the light! One year I did try backing them with foil, in the hope that the light would reflect onto the plants. But it didn't work. Then I got a solar powered automatic turner. That broke eventually... I don't bother too much now. I turn them if they're leaning over too much, and put them outside as much as possible during the day when the weather is OK. This helps to harden them off as well. But the tops of our wheelie bins tend to be covered with plants at a certain time or year - annoying if you want to throw anything away!
© Jo Edkins 2020 - Return to Garden index