Suburban Blight
For the reasons I go into below, I’ve purchased a small supply of an organic blight treatment called “Serenade.” It is prime blight season right now: For everyone’s protection, I will be spraying vulnerable plants and nearby soil with Serenade all over the garden this weekend. This was done by the former garden manager, Jen Hoff, in 2010 and 2009 and blight was not a problem at Flerra, while it was very common all over our geographical area. This product is safe enough to use and harvest the same day.
What Me, Worry?
After a long period of rain (or sometimes just a short one), one of the dangers to your veggie plants – especially tomatoes and potatoes – is early blight. Blight shows up as brown or black spots often surrounded by yellow, often on the lower branches of the plant. It appears on leaves mainly, but will also appear on stems. Here’s an example from my home tomato garden today (it’s a little hard to see the dark spots, because I took the photo against a black container):
Like the bugs and the fungus, blight is important to take care of, because it spreads fast and once it establishes a foothold, it will kill your plants. I had six of the biggest, most robust tomato plants we had ever grown die from blight two years ago, in a matter of days.
Blight is kinda heartbreaking – once it takes hold, it’s pretty fast, and almost unbeatable. Much worse than a bug problem. But caught early enough, it can be controlled. It won’t back down once it’s there, though, and needs to be tended to.
Blight comes out of the soil, and can also become airborne. It made a big resurgence in this area about two years ago due to contagion from tomato plant seedlings that were mass-produced for garden centers, especially the big box stores. Today, it’s in the wild.
Pointers about Avoiding and Dealing with Blight
Below are some pointers that I’ve picked up about blight. I’m not a huge expert – and I’d love to learn more from you guys, if you want to share where I’m wrong, or to share additional tips! There is a ton of information on the Web, too (some really good ag. school and state ag. dept.-type material), so surf away.
How to Avoid Blight
- Watch the weather. Blight loves rain followed by nice warm weather.
- Remove low-lying leaves. Once the plant gets strong, take off the branches or leaves that touch the ground. Pay attention to leaves that have dirt on them after a good rain, and consider removing these, too. This is a big gateway for blight, and bugs, too.
- Avoid getting the leaves wet while watering.
- Control weeds and bugs, which can spread blight as they touch or travel between plants.
- Use stalks or plant supports to keep leaves and branches off the ground.
- Consider removing tomato/potato leaves that are touching leaves of another tomato/potato plant. (Depending on the method of planting you use, this may not be doable.)
- Using mulch – either plastic or fabric mulch or natural mulch like salt-marsh hay – also helps keep the leaves out of contact with the soil.
How to Treat Blight
- Check for black or brown spots on leaves and stalks, often ringed in yellow.
- Snip! Remove the leaves of your plants that have spots, or anything that looks like a spot, or anything that you think might be a spot. In other words, if there is evidence of blight, be aggressive.
- Snip using fingernails – it makes a rougher edge for the wound, which is easier for the plant to heal.
- Know when to quit. When the blight has taken about 25%-30% of your plant, throw in the towel. The plant should be pulled up and safely disposed of, and the soil that contained the plant should be removed or securely covered.
- Safely dispose of any material you have removed. Don’t use it for composting or throw it aside near the garden. Put it in the trash.
- Rotate crops next year. Move your plants around next year to make sure you don’t plant blight-vulnerable plants in the same spot two years in a row.
Talk Back!
We’d love to hear from you. Hope you have a great holiday weekend, and we look forward to seeing you over at the garden. Hope this is helpful. Thanks for your time!
