Does anyone know a failsafe method for removing onion weed from the garden? Should you use poison for larger bulbs but dig out the little ones? Mine seems to be imported with compost I sometimes buy in bags. Does anyone else have this problem?
So far I have tried poisoning them, pouring boiling water on them, digging them up and even pulling the top growth off them, all of which helped to slowed them down but did not solve the problem. When digging up the bulbs, tiny little bulblets fell off and I end up with even more weeds than before. This year I tried digging up a couple of patches and at the same time taking out and replacing any surrounding soil where I thought the bulblets may have fallen. So far it seems to have worked and I"ve only had a couple of tiny bulbs regrow, which I removed before they were able to multiply and break up. For the inaccessible ones growing amongst my ground covers, I am going to try applying the new Roundup Gel (rather than digging up my plants). To minimise new weeds germinating, I am cutting off any flower heads as soon as they appear, before they are able to set seed, and not putting either the bulbs or the flower heads into my compost bin.
I"ve not found anything to kill onion weed successfully either. I"d say the best method is to remove the soil and start again.
One slow way (there is no fast way) is to wait till the flower is rising and break off the head then use a small syringe to put weed killer down the middle of the hollow stem. This kills all of the bulblets too. It beats digging them up and should not affect the ground cover. I find that doing this is as therapeutic as other forms of weeding.
Where the onion weed is mixed in with other plants, I wait until see a flower and then blast the onionweed plant with roundup after removing the flower. This means I dont keep poisoning the same plants over and over again, and for me checking each morning for new flowers kind of makes a game of it. For onion weed growing in inaccessible places I use the roundup gel, which seems to work, and for onion weed in loose soil I just keep cutting it off with a hoe to starve it. Does all this work? I dont know yet, but at least I feel I am doing something. Now for the madeira weed, which is even worse....
The trouble with my onion weed, as described above, many are too close to other plants to successfully kill without destroying other wanted plants. I have dug out, removed the flowers from those I could not safely dig or poison. When they flower this year I think I will obtain a syringe and inject the herbicide down the tube as Steve suggests.