Using the right soil and containers for your houseplants.

The only time you need to repot your houseplant is when:

• The houseplant is newly purchased and is still in its plastic nursery pot which doesn't fit in with your decor.

  If possible try not to repot a newly purchased houseplant as repotting will cause additional stress. Rather place the existing container inside your chosen pot for a month or two and then repot.

  Some people argue that a newly purchased plant is already stressed and the additional stress of repotting won't make much difference.

  I'll leave you to be the judge.

• The plant has become top heavy and keeps falling over.

  This is common with houseplants that grow quite tall. Make sure you choose a heavy enough container to counteract the plant's top heavyness.

• The soil dries out too quickly because there is not enough soil or the plant has become root bound.

  This is a situation that will face every indoor gardener. As a plant grows so does it's root mass and a time will come when there simply is not enough room in the pot.

  A plant is said to be root bound (some call it pot bound) when the root mass is so great that there is not enough soil to hold adequate water and nutrients necessary for the plant's continued survival.

  When a plant becomes root bound it's growth rate will slow and eventually stop, in severe cases that plant may die due to lack of water and nutrients.

Visible clues that indicate a plant is root bound include:

• Roots can be seen growing out the drainage holes of the pot.
• When you hold the plant upside down and remove the pot, the roots are a tightly tangled ball with little soil visible.

Important - Don't be in too much of a rush to repot a houseplant, do a little research first because some plants prefer to be root bound.

Choosing the right pot

Choose a pot that is an inch or two bigger than the existing pot. If you choose a pot that is too big, water will not evaporate quickly enough from the soil and the roots of your houseplant could rot.

Take into consideration that unglazed clay pots allow water to evaporate through the sides of the pot which means you will have to water more often.

When buying a new pot, make sure it has drain holes in the bottom and has a matching saucer or tray to catch water that drains from the pot.

If you have a decorative pot that has no holes in it, you can still use it by filling it with rocks and placing a normal pot on top of the rocks.

When you water your houseplant, the water will drain out of the pot into the spaces between the rocks. As long as you have left a space between the two pots, the water will evaporate and provide a humid micro climate above the pot.

A great place to look for pots is in the Gardening category at eBay.co.uk where you will always find loads of great bargains.

Repotting basics

Repotting is best done in early spring just as the new growth on your houseplant starts and is accomplished as follows:

• Wait until the soil in the pot is fairly dry and has started to pull away from the side of the pot.
• Place enough soil in the new pot so that when you have repotted the houseplant the existing soil will be roughly one inch from the top of the pot.
• Grasp the plant by the stem in one hand and the pot in the other and turn the pot upside down.
• Gently tap the pot and the plant should fall away from the pot.
• Gently loosen any compacted roots and trim if necessary.
• Place the houseplant into the new pot and pour soil into the gap between the roots (and old soil) and the new pot.
• Tap the pot against the table to settle the soil and pour in more if necessary.
• Thoroughly water the plant and top up with soil if the new soil settles any more.

Potting soil mix

The potting soil mix required by various houseplants varies from species to species. Do some research to find the correct mix for your houseplant.

A general purpose potting soil that can be used for a majority of houseplants consists of:

• 1 part sterilized soil.

  The soil can be sterilized by one of the following two methods:

  • Spread the soil not more than four inches deep in a non-plastic container and cover the container tightly with aluminum foil.

    Heat the soil to at least 180°F for 30 minutes. Do not allow the temperature to go above 200°F as high temperatures may produce plant toxins.

    After heating, let the container cool and remove it from the oven. Leave the aluminum foil in place until you are ready to use the soil as the heated soil gives off an odor.

  • If you only have a small amount of soil to sterilize, place the soil in a microwave dish and microwave the soil at full power for 90 seconds per kilogram (2.2 pounds). Don't use metal containers and aluminum foil when using a microwave.
• 1 part peat moss, compost, leaf mold, or fine bark.

  This organic material provides nutrients and also absorbs water which helps keep the potting mix moist.

• 1 part washed sharp sand.

  The sand is necessary to help drain the potting mix of excess water and to provide air pockets necessary for healthy roots.

  The sand, which is the same as used by builders, should be washed with copious amounts of clean water before using it in a potting mix.

You can vary this mix to suit any type of houseplant, for example you can increase the ratio of sand for cactus and succulents.