Some of the dirtiest words — for gardeners, that is — have nothing to do with human anatomy or sexuality, but rather the pests and diseases that threaten their crops.
This week we’re featuring two common, dirty, dreadful diseases that have the potential to kill plants if not caught early and treated. Root rot and blight — a fungi and disease — generally show up when there’s overwatering and have limited treatment options. That’s why it’s crucial to maintain healthy, well-drained plants in as sterile an environment as possible.
Root Rot: Typically caused by prolonged overwatering, oxygen deprivation or by fungus-infected soil, root rot symptoms include yellowing, possibly wilting leaves. The fungi basically blocks roots’ oxygen intake, eventually leading to decaying, dying roots; in essence you can lose the entire plant if the problem isn’t caught and treated early on.
The best way to diagnose root rot is to inspect the roots. Infected roots can appear light brown to dark brown and turn even black, feel mushy and slimy and maybe even fall off. In the worst-case scenario, the plant’s base can become infected and turn dark.
Quickly treating an infected plant is your best defense, and even then, the plant’s chances of full recovery are slim. No spray will cure this devastating ailment, and cultural controls — such as preventing root-eating insects, fungi and bacteria, maintaining a proper pH, using a clean growing medium and maintaining adequate calcium levels — are the only defense.
Upon detection, immediately remove the plant from the soil or growing medium and wash the roots under running water, washing away as much soil and affected roots as possible. Be careful while doing this, your poor plant is already in a fragile state.
Then get a sharp, sterile pair of scissors or trimming shears and cut off any rotting roots; if the disease is significant enough, you may have to remove a large portion of the root system.
Also get rid of the soil or growing medium the plant was in and thoroughly wash the container with a bleach-water solution to rid it of any lingering fungus. And, as a precaution, dip the healthy roots in a fungicide solution to kill any remaining root rot. Replant using new potting mix in a clean container with good drainage and only water when the soil is dry.
Blight: This is a general term that describes a variety of diseases caused by fungus, usually showing up a few weeks before harvest. Symptoms of blight include leaves that suddenly yellow and wilt, or have dark, blotchy spots, which can all lead to death. It’s quickly spread, hard to control when in advanced stages and sometimes the only way to rid your plants of the problem is to rid yourself of the plants.
Prevention, as with all pests, diseases and fungal infections, is the key to combatting blight. Maintain a well-drained growing medium and avoid excessively fertilizing with nitrogen.