First, it is extremely unusual for the same disease problems to affect a whole range of different plants - they are typically very plant-specific (the exception being powdery mildew). Therefore, it is highly unlikely that the same problem is affecting all your plants and so the same blanket treatment will not help. It is of primary importance to get an accurate diagnosis of the specific problem for each plant in question and then utilize the appropriate remedy. Hopefully someone on staff at a better garden center can help or check out a Master Gardener clinic or your local extension service. Often, the incidence of a lot of plant problems is more culturally related than an actual disease issue - fix the growing condition and the problem disappears. Fungal issues like leaf spot are often related to weather, overwatering, watering at the wrong time of day (leaving water on foliage overnight), poor drainage, lack of air circulation or even proper garden clean-up and sanitation. And mulching in winter can help a lot - a good layer of mulch smothers fungal spores that can overwinter on the soil surface and prevent them from splashing up with rains and reinfecting. Your hydrangea issue is most likely cercospora leaf spot, a very common problem with a number of hydrangea types. If you read the attached info sheet, you'll notice that the condition is primarily due to cultural issues. Correct those and you will correct the problem. Here is a link that might be useful: Cercospora leaf spot.

tantanman, Thank you so much for your post and insight regarding your use of Bt (I'm assuming the 'K' strain bacillus) on orange dog caterpillars. Fortunately and as far as I'm aware, we here in the Bay Area aren't as affected with citrus leaf miners as our poor friends in SoCal/San Diego who must rely on harsher systemic insecticides like Imidacloprid. So, I should be able to use Bt on my species of leafrollers with similar positive results as you. Shortly/immediately after my initial post (and since no useful remedies were offered here), I went to my local nursery and did indeed purchase (among other things) some Bt(k), and had/have every intention of using during the growing season. However, I was still concerned that multiple applications of BT might need to be administered (as you confirm above) for full control. I wanted to knock out ALL current eating caterpillars. What I also purchased at the garden center was horticultural oil (HO) and Neem oil. Neem oil, I'd read, acts as a powerful anti-feedant and synthetic hormone that disrupts insects' metamorphic life cycle (so that they can't progress to the next stage). HO, in addition to smothering insects (so that they in essence can't breathe) like scales, mites, etc., also targets caterpillar eggs (so I'd read!). Perfect, I thought, but not knowing what to apply first (Neem or HO), I applied both - first the Neem, followed by the HO the next day (late afternoon) after the Need had dried. Well it's been a week, and I'm happy to report that not only have the scales on my one potted Meyer almost fully dried out, but I don't see any evidence of caterpillars (I just checked!) on any of the three in-ground Meyers or Trovita! For safe measure, I'm going to re-apply the Neem again today, since I've read it breaks down fairly quickly from the sun's UV rays. Hereafter, I'm not sure what I'm going to do. I could certainly commence with using Bt on a periodic basis come the growing season; however, as I alluded above, there are many on this forum who have used FE to control other insects (though I don't recall seeing any mention of its use on caterpillars). There's anecdotal evidence that it may act similar to HO by the oil smothering insects. So, I may (instead of using Bt in Spring) just do the experiment and try the weekly applications of FE and see what happens (plus, I'm really curious what the answer will be!). Also, I kinda like the added benefit that FE has as a foliar fertilizer... If I end up using FE, I'll post an update on its effects on caterpillars at some point in the future (and whether or not I had to rely on Bt after all!). Tim

I'd always reach for the dedicated horticultural item. Manufacturers of household items routinely switch formulations depending on what supply is cheaper. Horticultural applications will be the same from one jug to the next and from one year to the next-unless specifically spelled out. Just a s Dawn for Dishes might work just as well as the actual insecticidal soap, it might not and could cause phytotoxicity-damage to the very plant(s) you're trying to protect. I'd strongly urge you to only use actual horticultural products. +om

Systemics are not for me. I have no desire to eat citrus that has been treated with them. Here in Calif. all citrus sold at nurseries is now required to be treated systemically for the citrus greening carrying(maybe?) bug. If you read up on it, you'll see that imidacloprid can be found in flowers, fruit, pollen, and nectar two years after application. There was one plant (I forget which kind) where it was detected 6 years later. It's toxic to bees and pollinating insects, and who know...humans too? I've spent many hours, usually at night, turning over small young citrus leaves looking for the mines and the shiny surface that create, and carefully squeezing the larva. It takes a light touch since the leave are usually very young and delicate, but it's doable and kind of satisfying. Especially if you only have one tree. Season55, the time to start looking for them is springtime when your tree is flushing. They usually only lay the eggs on leaves that aren't hardened. I'm not sure how long it takes a new citrus leaf to harden, but I'm guessing around 3 weeks. I find it's easier to spot the beginning tunnels at night with a flashlight, but that's just me. The moths tend to lay on the underside of the young leaves, near the center vein, often near the base of the leaf. The larva will mine the leaf for some time, I believe it's weeks, and end up at the edge of the leaf. It goes through a number of instar stages(3) then a pupa stage where it rolls the edge of the leaf over itself for protection. So if you spot a young leaf with it's edge rolled over, that's your last change to squish the CLM. I also tested the ISCAlure citrus leaf miner traps which are now available on Amazon at what seems to be a reasonable price. I'll be ordering a set next spring around May when the moths come out of hiding. My testing time was inconclusive, the traps do catch some of the males but they aren't considered a cure-all. But I think if you get out early with the traps, while the infestation is small or just before it is starting, along with something like Neem oil or Ultrafine oil, you might be able to stop them, if you don't have too many trees to worry about They don't attack every citrus tree I have, and most of mine are smallish and in containers.