Today marks a sad, sad, truly gut-wrenching day in the history of my garden. It appears the Basil Downy Mildew (BDM) has reared its ugly head and spread throughout my basil plants faster than Usain Bolt in Berlin.
The worst thing about this disease is that there is nothing that can be done to rid your plants of it. You can slow it down, but given time it will eventually spread and kill them all 🙁
What Is Basil Downy Mildew?
Downy Mildew is a destructive disease that affects several plant varieties. In terms of basil, the origin of the disease has been stated as dating back to Uganda in 1933. In the Western World, it’s been stated that the disease first reached Italy in 2004, and then spread to the USA in 2007 with increasing prevalence since then. It is a ruthless killer of plants and under the right conditions can spread rapidly.
How To Identify Basil Downy Mildey
You will first start to notice small yellow lesions on the surface of the leaves of your basil plant. These will spread and become larger, eventually turning brown and killing the leaf entirely. It can initially resemble a nutrient deficiency in the plant. One way to confirm if you have BDM is by turning the leaf over to inspect the underside – if there is a powdery black substance present, then the worst has been confirmed. You can look through my photos to see what it looks like.
Can BDM Be Treated?
There is no known solution to remove the disease from infected plants.
How To Prevent BDM?
Start by selecting a less susceptible variety of basil to grow. If you already have your gardening in full swing then do what you can to reduce leaf wetness and minimizes humidity. This means ensuring you water at ground level and not overhead for the plant, use drip irrigation systems etc. Place the plant in a sunny position with good airflow is about the best you can do.
What To Do After You Get Basil Downy Mildew
Immediately remove all infected plants. Start by placing a plastic bag over the entire infected plant. You need to do this to ensure the spores do not spread to other plants in your garden that might not yet be infected. Do not try to compost any infected leaves or plants, the spores have a very long life (around 8 years) and so you risk reinfection. Also, do not attempt to save any seeds from the infected plants.
You will need to be aware that it is likely that the soil is now infected from BDM and so remember not to plant basil in the same place, ensure proper crop rotation.
Sunny days are the optimum time to destroy the basil plants as any spores that travel due to the plant being disturbed will be killed by UV radiation from the sun.
Is Basil Downy Mildew Safe To Eat?
It is safe to eat, but not recommended.
Are There Downey Mildew Resistant Basil Seeds?
Yes, luckily there is. Somewhat resistant. There is a basil seed called Eleonora that you can now purchase that provides an intermediate resistance to downey mildew. You can get them places like Johnny Seeds or for organic seeds try High Mowing Seeds.