Flax plants - Dying back around base- Megan, Vic

Hope you can help !

I have a garden bed full of flax plants.  A row of green ones infront of a row purple ones.  With the drought in Victoria, and heavy watering restrictions in Geelong, the plants have only been watered with grey water from the washing machine, and little rain.  The purple flax have some sort of fungus/disease which is white and powdery mainly at the bottom of the plant.  There is also lots of spider webs and snails though the plant.  The plants are just over a year old and have gotten very thick in this time. We were advised to trim them right down which we have done.  We have also attempted to treat the white disease with Pestoil.  The green flax are going brown and dying.  Both plants begin dying fromthe outside, and eventually the entire plant basically rots and can be ripped out of the ground with very little effort.  It's as though the roots are either rotting or being eaten.  We have attached a photo, please help with some advice.  Megan, Geelong, Victoria.

 

Hi Megan,

                    Thanks for the comprehensive run down of the situation and the photos.    From what you have told us we believe that the problem is due to the nature of your grey water and it's concentration around the roots.   We suggest that you stop using the grey water.........   

For the plants to recover you will need to bucket some fresh water over the plants to wash out the agents which are killing the roots.   We know the restrictions are very harsh, so next time you get a bit of rain place some buckets outside to catch some rain and use that to water the flax.   Do not fertilise or use any other treatment except clean water.   All the pests you see around the plant, are not the cause of the problem.   They are being attracted because the plants are sick. 

Why is the grey water a problem ?   

Grey water is okay to use now and then,  but due to the following reasons it can actually kill plants.   Particularly if you have clay soils, which do not drain well. 

1.    Detergents -  Washing powders use a type of surfactant (soapy stuff) which becomes toxic to plants if used in large amounts.

2.    Nutrients -  Washing detergents actually have nutrients (phosphates) of a type, which once concentrated are toxic to plants. 

3.    Washing powers are Caustic, so they change the soil Ph and burn the roots of plants as well. 

The soil will be pretty sick, so you will need to flush out all the bad stuff and the flax will regenerate. 

Ps. Just a note on washing powers, keep them away from animals, dogs particularly, as it can make them very sick (and worse) if ingested. 

Hope this info helps, let us know how it goes.

Regards questions@gardenguide.com.au