First I want to say hello to the forum, I think it is a great resource and comunity!
Now about the aphids. I know they come when plants are stressed and avoiding stress is enough to prevent them, but when not using irrigation we can count on some stressed plants even if for short periods of time. I also understand that ants take care of them underground and also protect them on the plant.
So I thod: How can I make ants stop helping the aphids and since the aphids provide sugar to the ants I started droping fruit prunings at the base of the afected plants. Two days later the aphids were alone and another two days later there were no aphids on the plant! (presumably predators got them). Plus the ants are now protecting in some way the base of the plant.
I am not sure this would work every time since I had very few plants with aphids (3) but it may be the case. Maybe this could be used in trees too? I imaging geting a small basket in the three with some sugary thing.
Hot and dry during the peak of the summer tends to bring the infestation of aphids, but mostly to crops more prone to them (like tomatoes).
But I always only had this problem indoors, never outdoors. Because indoors it can get really hot, and plants like tomatoes in containers can feel a lot of water stress and thus aphids attack. Give them space, cooler weather, proper fertility and enough water. Too much nitrogen also invited aphids.
Inside the house I control the aphids by making a spray bottle with 1 tsp organic castile soap and a few drops of tea tree oil. It works good to control them, then as weather cools down as now, I bring the plants outside shake the aphids out, and then I bring them back inside and there is no aphid problem anymore.
in Portugal, sheltered terraces facing eastwards, high water table, uphill original forest of pines, oaks and chestnuts. 2000m2
in Iceland: converted flat lawn, compacted poor soil, cold, windy, humid climate, cold, short summer. 50m2
I have one of those powder shooter things, i bought it years ago then packed it away because I have never had a use for it other than being a waste of my money.
BUT 3 years later it finaly came into serious use as aphids where killing 75% of my elderberry, if I had known sooner i wouldn't of lost so much of the tree.
I essentially blew diatomaceous earth on the undersides of all tree's being effective, It tries them out, disrupts the ants, isn't a poison and washes off when i want it to.
I don't like things that annihilate, and i'm not a fan of spraying soap on living things in any lethal dose for an insect.
It works because it's matting and tends to catch on the leaves or fall to the lower garden, I like to do it when I see 3-5 days before rain.
What sad is how many times i just threw it in the air before even considering putting it in front of a hand crank fan.
Hello everyone, I just joined your forum - looks really interesting. I live in Kenya and of course we also can have stressed, thirsty plants (although of course we do try to minimise this!) Re the aphid/ant thing, I also heard that if you put dry coffee grounds around the base of the host plant, the ants wont walk through it and therefore cant "service" the aphids. I havent used it yet, but it may work.
Welcome aboard Joannah. We have a framer friend who suggests coffee grounds for all sorts of pest management - like weevils eating corn seeds, plant the seeds with a small handful of coffee grounds in the hole. In France of course they drink LOADS of coffee - us being British are more into tea. Hmmm wonder if tea leaves would have the same effect?
I almost wish I had some infested plants now, I´ve been unable to find out if my idea worked or if it was just ´´luck´´. I have many small cold compost piles around the garden and the ants are frecuently searching through the less buried kitchen scraps.
There's some lambs quarters with a thick infestation of dark aphids right upslope from some lush tomato plants in my cedar hugel. I haven't seen any in the tomatoes. I left them there, hoping to feed the ladybugs, not thinking they might like the tomatoes too. So far so good. Anyway, maybe they prefer the lambs quarters? Is this a thing? Like a sacrificial anode to prevent rust. Just an idea.
I used to try neem and soap on aphids; they knocked them back but didn't really kill them (and also burned the leaves somewhat). So I resorted to buying some chewing tobacco and brewing some tea from that. Very lethal. I've only used this on indoor plants; be advised it's very toxic (but not synthetic) and will kill indiscriminately. Perfect for indoors where there are no natural predators in play.
"I must Create a System, or be enslaved by another Man's"--William Blake
For trees run a glue trap bead round the tree to catch the ants as they climb. You will need multiple beads and you will have to renew them every few days. Part two is plant predator support plants near the trees.
I used to have a much bigger aphid problem than I do now. It's so much better, I believe because of a a couple of factors.
First, I don't fertilize with store-bought nitrogen anymore, so there isn't a big flush of lush new tender growth all at once that the aphids go crazy for. The trees and other plants grow slower, but they don't offer as lush a target for the little sap suckers.
Second, I have a pretty extensive poly-culture of supportive plants throughout the garden, including lots of flowering plants, herbs, bulbs, ground-covers, bio-mass producers (comfrey), insect repellent plants (tansy is my current favorite), and veggies, veggies, veggies. I don't plant anything in a row -- everything is planted in little drifts (carrots, beets, lettuce, okra, etc.) or in single plants where there is a window of space (peppers, tomatoes, various vines). The result is a massive poly culture that encourages an equally massive insect community, from the tops of my tallest trees (avocados) to the surface of the soil and even below. If you want aphid killers to populate your garden (lady bthirugs, spiders, praying mantis'), then you've got to build habitat that they want to live in.
Third, because aphids reproduce so rapidly, while lady buds and other good insects are much slower in their reproductive cycle, what ever you use to kill the aphid may have a much greater harmful impact upon your good bugs. If you use something like neem oil or tobacco juice, it isn't just hard on the aphids, but also the spiders and good guys.
It took me about 4 years once I stopped using any bug sprays (even natural ones) to see the system come into balance. There are still times where I see an infestation of one sort or another, but generally, because things are so spread out and not planted all in one spot, even if the aphids get one area, they won't get the others.
Slugs, on the other hand, are the bane of my existence. I've got a great lizard population doing their part, but once the slugs find the cabbage, it's hard to root them all out and save the plants.
Best of luck.
"The rule of no realm is mine. But all worthy things that are in peril as the world now stands, these are my care. And for my part, I shall not wholly fail in my task if anything that passes through this night can still grow fairer or bear fruit and flower again in days to come. For I too am a steward. Did you not know?" Gandolf
Thanks for all the good advise. We have a small home operarion in South Central Virginia. Had some overwintered plants that we brought in to our seeding area. Those at least is where we are trying to put the source of our aphid infestation from. We tried the neem and insecticidal organic soap to control. Neither seemed to keep ahead of the aphids. And would take and burn our tender shoots also. We are planning in segregation of plants next season, using Diatomaceous earth, (possibly if can keep mess down in house). The chewing tobacco tea sounded promising. And the castile soap at 1 tsp, several (?) drops of tea tree oil, in (assume 1 gallon of water).
The coffee ground control sounds like a great standard also. Hope to continue to add and build to our stewardship efforts.