What is the best potting soil mixture to use?

(Question)

HI
what is the best potting soil to mixture for my
house plants such as geraniums

I see that they are not doing to well lately and I just wanted to know what is best for them

since they don’t look all that great now

(Answer)

 

There could be a number of reasons why your houseplants are looking poorly.  They may be pot bound; they may be suffering from a nutrient deficiency and need fertilizer; or they may be suffering from overwatering.

You can address all of these issues by repotting the plants in growing medium, which will give you chance to check for root damage caused by overwatering.

There are two main categories of mix.  Those which contain soil, and soilless mixes.

Mixes which include actual soil tend to be heavier, contain more nutrients and hold moisture longer.  Soilless mixes are lighter, easier to handle but also more likely to dry out and lose nutrients more quickly. Despite these drawbacks, soilless mixes are often preferred for indoor plants.

Which mix you chose can be a matter of personal preference, although some indoor plants may have particular requirements, i.e. sand to ensure quick draining in the case of cacti or extra organic matter in the case of tropical plants.

Geraniums require well-draining potting soil and a thorough watering when the soil surface is dry. An all purpose soilless mix available from your local garden centre would be appropriate.  It will drain well but will require extra nutrients. For this reason you should fertilize your plant with a liquid fertilizer high in phosphorus (to encourage strong roots) and potassium (to encourage flowering) but low in nitrogen (as a high nitrogen fertilizer will encourage vigorous grow but no flowers).  The fertilizer should be applied only during the growing season  – spring through early fall – and not during the winter months.

Here is a link to a Toronto Master Gardeners Guide on Pelargonium which contains more detailed information on these plants.