Can you be too kind to a houseplant?
Imagine you are a plant. You are growing in bright sunny conditions. For most of the summer the weather is dry but there is enough water and nourishment in the soil to keep you healthy. In winter the weather is slightly wetter but the soil has good drainage and never becomes waterlogged. Now imagine that you are dug up, taken to a garden centre and sold as a houseplant. How do you think things might change?

You are bought by a person who wants to look after you but is not sure how to do it. When you reach their home, you are put by the fireplace. It is shady there and you begin to make less food. As you make less food, you do not have enough materials and energy for growth and so you do not increase in size. Your new owner sees this and thinks that you need more water. She waters your soil until small pools form on the top.

Inside the pot, the water fills all the spaces between the lumps of soil. This means that your roots cannot take in as much air as they need. Your roots need air to help them take up nutrients in the soil. As you take in fewer nutrients, you have still fewer materials for growth.

The extra water in your soil makes your leaves turn yellow and wilt. Your new owner thinks that the wilting is due to too little water and tries to add more water to the pot. Eventually she realises that perhaps there is too much water in the pot and decides to dry you out. She lights the gas fire and turns up the heat.

Your new owner had to struggle with the gas fire to get it working and it only burst into flame when she had worked the clicker for the sixth time. This meant that quantities of gas drifted through the air. The gas entered some of your leaves and made them drop off your stem. Your owner is now alarmed at your loss of leaves and turns up the heat to dry you out faster. The extra heat scorches some of the leaves next to the fire and brown marks appear on them.

By now your new owner is very concerned about you and decides that perhaps you could dry out more naturally in a sunny window. At last you are placed in surroundings that are similar to your home. As the days go by the water in the pot dries out but where is your new owner?

She has gone away on holiday. Every day the sun beats down on your stem. In your home it would also beat down on the ground but your roots buried deep in the soil would keep cool. Here your roots are in a small pot which heats up quickly. The soil begins to bake in the heat and your roots begin to die. Only a little water is left in your body and your leaves wilt to try and conserve it.

Not a moment to soon, your owner returns from her holiday and sees the poor state of your health. She quickly waters you again but this time does not waterlog the pot. She has been reading about plant care on her holiday and is determined to make you survive. In the coming months she changes the conditions around you to match the conditions you would have had in your natural home. In fact you cannot tell the difference and begin to grow again. In a few months you please your new owner greatly by bursting into flower.

Do houseplants wilt when they have either too little or too much water?
Yes, they do, but you can tell the difference. If the plant is over watered the leaves are likely to be yellow. If the plant has been over watered for some time the pot may also have green slime on it. If the plant is too dry the leaves may shrivel and turn brown. Both watering too much and too little can make the leaves drop off.

How do leaves save water by wilting?
They have holes on the underside of their leaves. Water vapour escapes through these holes. If the leaves wilt, their undersurfaces come close together. This helps to trap any water vapour that has escaped and holds it in the air close to the leaves. The water vapour in the air stops more water vapour escaping and helps to keep more water in the plant.

Can draughts harm houseplants?
Yes, they can. If a plant is left by an open door or window a draught can blow across its leaves. This can cool and dry them. After a few days in a draughty place a houseplant may be dead. Some plants on a windowsill may still be in a slight draught even when the
window is shut. This draught is caused by cracks in the window frame. The cracks must be sealed if plants are to thrive on the windowsill.

Where can cold harm a plant in a room?
If the plant is kept on a windowsill in the winter it may become cold overnight when the curtains are closed. The curtains keep heat from the room reaching the plant. If the weather is cold outside, heat will be drawn through the window from the air around the plant. This may make it too cold for the plant to survive.

Can a plant have brown spots on its leaves without them being scorched?
Yes, it can. Brown marks may be due to over watering, over feeding, too much sunlight, draughts or too much gas in the air.

A plant occasionally produces a yellow leaf which falls off. Is it unhealthy?
No. It is normal for a plant to loose a leaf occasionally. If a few leaves turn yellow and fall off at once this indicates that something is wrong. The air may be too dry, there may be a draught or the plant may have been over watered. A plant may drop its buds or flowers for the same reason.

Are houseplants collected from the wild like in the story?
Not today. In the past, when voyages of discovery were made, plants were dug up and brought back to Britain and other seafaring countries for scientists to examine. The plants were grown in greenhouses and bred. In time more plants were collected and bred for sale. Today the houseplants that you buy have been bred specially for sale.

What is the best way to look after a houseplant?
It is better not to follow the ideas of the person in the story. The person tried to rear the plant by a method called 'trial and error'. This causes too much suffering to the plant and may kill it. Most houseplants have a care label, planted in the pot. This tells you the conditions that the plant needs and you should try to provide them in your home. You can also ask for extra advice from people working at a garden centre and can find more information in books about houseplants. The main mistake that causes harm to houseplants is over watering.