OK, all you Brussels sprouts lovers! Who knows how to really control (preferably eliminate) the hordes of black aphids that have descended upon my every attempt to grow sprouts in 50 years and 10 countries? Well, short of high-strength chemical insecticides, that is! I've tried just about everything else with little success.
1 cup vegetable oil
1 1/2 cup water
2 teaspoons dish soap or Murphy’s soap
Spray mixture on aphids every few days until the aphids are gone. This suffocates the aphids. Keep plants treated with this solution out of direct sunlight, oil may magnify the sunlight and burn plants.
Bring in predators as an organic control of aphids. Aphid predators are a natural way to kill aphids. Lacewings, ladybugs and aphid predator (an actual bug called that). Easy to find on the internet, introduce these beneficials to kill aphids. Planting mint, fennel, dill, yarrow, clover and dandelions will attract these insects to your garden. Careful... some of these plants are highly invasive.
Companion plants for aphid control. Plants that are attractive to aphids can really help with an aphid infestation. Plants like nasturtiums, asters, mums, cosmos, hollyhocks, larkspur, tuberous begonias, verbena, dahlias, and zinnias are very attractive to aphids and are especially good for organic control of aphids. Grow these plants away from the plants you wish to keep aphids off. They will act as a lure, keeping the aphids away from the plants you want to keep aphid-free. You can also place garlic or onion plants near the infested plants. The smell of these plants drives the aphids away. Plant garlic and onions in pots for mobile aphid control.
You can also spray the plant with your garden hose to knock the aphids off. Spray the plant every day until the plant is aphid free. While any of these methods will work for getting rid of aphids, combining them will increase their effectiveness as a natural way to kill aphids.
(Summary from several articles I have about the nasty little aphids)
I agree with nearly everything that you've said, jewlybug, because they all work for me with everything EXCEPT Brussels sprouts. In fact, I am convinced that Brussels sprouts ARE an aphid-lure plant that can probably even be used to keep aphids away from your cosmos and nasturtiums.
I never thought about aphids on dahlias. I grow a lot of them and have never had an aphid problem. Isn't that odd?
Have you had luck growing aphid-free Brussels sprouts?
I need some encouragement here!
Sorry.. haven't been around in a while. In answer to your question... no. I haven't grown brussel Sprouts yet. We wanted to put some in this year. I'm interested in the fact that you feel like they are an aphid-lure. Maybe the onion/garlic in a pots around them would be the answer to that. I hope you have better luck. Brussel Sprouts are yummy and I want to get a good yield when we plant them this year. Let us know is you come up with anything intesting ;D