Star Wars has microscopic, intelligent lifeforms called midi-chlorians that live within the cells of all living beings. That’s science-fiction. Apparently, midi-chlorians influence the ‘force’, which is all important to the Star Wars story. Plants, on the other hand have micro-organisms that live between plant cells called endophytes. That’s science-fact. Endophytes can be all important to the plant’s survival.

The existence of endophytes sometimes called endoflora, shouldn’t come as a surprise to you – your mouth is full of them, your gut is teeming with them and you would be one of a very few if you did not to have colonies of mites living in your eyelashes (although technically mites would be fauna, but let’s not get too picky around our microscopic organisms).

Most horticulturalists will know of mycorrhizal fungi, and how they are associated with roots, although many will be surprised to find out that there is not one mycorrhiza fungi but thousands. Mycorrhiza are a type of endophyte, but endophytes in the form of bacterium or fungus can also be found within the leaves, stems, flowers, fruit and possibly seeds as well.

Some endophytes can colonize thousands of different plant species, while others are restricted to single plant families. They are mostly mutualistic (endosymbionts) and it is believed that some endophytes help protect plants against insect and plant pathogens and others can help resist environmental stress. A plant’s survival can be dependent on the presence of endophytes.

Knowing of the existence of endophytes is nice, but how do we use that knowledge – what do we do with what we know?

Plants have had relationships with micro-organisms since plants stopped being micro-organisms and became macro-organisms [got big]. We don’t fully understand all the details but it’s safe to say that these relationships may be more complex than simply mutualistic.

For most complex relationships to function there must be a balance, some ratio of this to that – and this is where we come in. Even if we don’t know what those ratios are, the plants do; so try not to upset the balance, try to restore it.

The urban environment by default in not a natural one, we can’t (and shouldn’t) try to make it what it once was – that environment is gone, we need to manage what we’ve got. Species diversity is key to a healthy growing environment. To aid species diversity and increase the chances of micro-organism colonisation, eco-source your plants. Select plants from environments not necessarily representative of what was once there, but what is there now and increasingly what will be there in the future [climate change]. Let your leaf litter lie – try and get some natural nutrient cycling going on, not only will it help the plant it will help the soil. And stop the fertiliser – the easiest way to throw your biological system out of balance is to fertilise it.

Maybe endophytes are midi-chlorians in a galaxy far far away, but here on Earth we need to be aware of the existence of complex relationships that we can’t see – we need to let our plants have the option maintaining those relationships and we need to do what we can to keep things in balance.