Plants need their roots to be healthy so that they can take up water and nutrients from the soil to keep them fed. But, sometimes the roots can become sick and they aren’t able to do the job that they are supposed to do.
Root rot is a disease that affects the roots of plants. It is actually called phytophthora which is pronounced: fye-toff-thor-a. Sometimes it is also referred to as ‘dieback’.
WHAT DOES IT LOOK LIKE?
The roots of most plants are pale or cream with tiny little hairs on them but if they have root rot, these hairs become a dark brown colour and soggy and this then transfers to the larger roots.
The leaves on the plants start to yellow and even though they have been given enough water, it wilts as if it is drying out.
Wounds can sometimes appear on the base of the stem and gum or sap can weep from this spot.
Eventually the plant may die.
WHICH PLANTS GET ROOT ROT?
Almost any plant can get root rot from the smallest herbs and vegetables in pots to the largest trees. Both indoor and outdoor plants can get root rot disease. A lot of Australian native plants such as eucalypts, banksias, grevilleas and eucalypts get root rot really easily which is why areas of our native bush are often quarantined from people being able to visit.
HOW DO PLANTS GET ROOT ROT?
Overwatering is the most common cause of root rot diseases in indoor plants and potted plants. Having their roots always in water makes it difficult for their roots to get the air that they need and this causes them to rot.
The spores of root rot diseases such as phytophthora are often spread by people walking from diseased soil to healthy soil or from soil being moved. It can also spread in the air, on insects or even on crawling insects in the soil and some spores can even swim through very wet soil!
WHAT CAN YOU DO?
Prevention is definitely the best cure for root rot disease as it is very difficult to stop. There are fungicides that can be applied but these are expensive and shouldn’t be used on vegetable or edible plants.
Use fresh, premium potting mix when planting into pots as this will drain really well and won’t carry any active spores. Only water the plants when the soil doesn’t feel moist when you touch it with your finger. And, don’t overwater the rest of the garden either as this can also cause outbreaks of root rot diseases. Besides, it probably doesn’t need as much as you think.
Healthy white roots
Roots with root rot
Very diseased roots