Spots On Leaves Of Several Plants

Question

There are marks all over the foliage of several of my plants… my dahlias, catmint, and salvia most noticeably. I can’t figure out what’s causing the spots and if it’s the same thing for all of the plants or if maybe my dahlias are suffering from something different than the catmint and salvia. The new growth appears healthy and then becomes marked later. The catmint and salvia seem to be blooming normally. The dahlias have several buds, but their flowers do not look healthy. Any ideas on what this might be and how I can help them?

• 
• 
• 
• 
• 

Answer 1

These seem to all have the same problem. This is spider mite damage. You might notice tiny red mites crawling on the plant. They like the undersides of leaves, so look there. This is the worst problem that I have in my indoor garden since there are no natural predators to eat them. Outdoors you could introduce predator insects to eat them, like predatory mites. I wouldn't advise that indoors, though.

https://www.gardeningknowhow.com/plant-problems/pests/insects/red-spider-mites.htm

Treatment needs to be consistent. They seem to take whatever you throw at them. Azadirachtin is an extract of neem oil. This is what I recommend.

https://www.gardeningknowhow.com/plant-problems/pests/pesticides/azadirachtin-vs-neem-oil.htm