Can You Compost Diseased Plants?
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No, not in a typical home pile. Plant diseases such as clubroot, fusarium wilt and verticillium wilt can survive a cool pile and spread back to your garden. Send diseased material to municipal yard waste or the trash.
At a glance
| Home compost pile | No |
|---|---|
| Green or brown | Neither (not a green or brown input) |
| Moisture | Wet |
| Prep | None needed |
| Worm bin | No |
| Bokashi | No |
What to do with diseased plants instead
Municipal yard-waste programs run large, hot piles that handle most plant diseases. A hot pile held above about 131°F (55°C) for several days and turned kills many pathogens, but it's a gamble for home composters.
Bag diseased leaves, stems and fruit and put them in municipal yard-waste collection if your program accepts them, or in the trash. Clean pruners after cutting diseased growth. Healthy prunings from the same plant are fine for the pile.
What goes wrong
Home piles rarely heat evenly, so pathogens survive on the cool edges and return when you spread the compost. If diseased material went in, keep that compost away from vegetable beds and from the same plant family. Soil-borne diseases are the hardest to get rid of once established.
Worm bins and bokashi
Worm bin: Worm bins don't heat up at all, so keep diseased plants out.
Bokashi: Bokashi isn't a proven way to kill plant pathogens, so keep diseased material out.
Balancing the rest of your pile? Check the balance with the compost mix calculator.
From hopcompost.com/can-you-compost/diseased-plants/ · General guidance, not professional advice.
Frequently asked questions
Can you compost tomato plants with blight?
It's safest not to. Bag blighted plants for yard waste or the trash, especially if you grow tomatoes and potatoes every year.
Can you compost plants with powdery mildew?
The cautious answer is no: bag it. If you do add mildewed leaves, only put them in a pile that genuinely gets hot.
Does hot composting kill plant diseases?
Sustained heat of about 131°F (55°C) or more for several days kills many pathogens, but only if every part of the pile passes through the hot core. Some, like clubroot, are persistent, so municipal collection is the safer bet.