From the Viette's Views Gardening Blog
They break dormancy early, much earlier than your grass wakes up from its winter nap and consequently, they are quite obvious in the lawn, standing out against the brownish winter grass. This is what drives some gardeners bonkers. Once they start in the early spring, they grow very quickly and soon these tufts of bright green wild onions reach 6″ to 10″ tall making your lawn look quite unkempt and scraggly.
I say wild onions, but these could also be patches of wild garlic. Both wild onion and wild garlic are cool season perennial weeds that come up each year from small bulbs similar to the onion sets that you plant in your vegetable garden. If allowed to flower, they produce seeds which fall to the ground and germinate. This is more likely to occur when they are growing in the garden, though, not in the lawn. The patches that grow in the lawn are normally mowed down before they get a chance to flower and set seed. Ahhh, the fragrance of fresh mown wild onions!
Pulling them doesn’t work because invariably you just end up breaking off the top and leaving the bulbs in the ground to come back up the next year. Been there, done that!
The most environmentally friendly way to “try” to get rid of them is to dig them out which is easier said than done!
You have to be very careful to get all the bulbs in the cluster including the roots and any tiny bulblets that have formed off the main bulb. This is a bit easier in a garden than in the lawn but is usually not a very effective way to control them. A digging tool like a dandelion digger makes the job a little more successful but it’s really hard to get every bulblet. If you are set on digging them out, do yourself a favor and irrigate the lawn and garden first or wait until after a good soaking rain. This will soften the soil and make it easier to pull out the entire cluster of bulbs.
In the lawn, wild onions and garlic are unsightly for a few weeks in the spring but once you mow and the grass begins to grow strongly, they blend right in and by late spring they go dormant and disappear anyway. Mowing slows them down especially since it keeps them from flowering and setting seed, but they will still grow back from the bulb the following spring.
If you can’t stand them in your grass and digging them is not feasible, you can spot treat the patches of wild onion/garlic in your lawn with a selective broadleaf herbicide like Clear Choice. Spot treating is more environmentally responsible because you are targeting the specific problem with less herbicide and very little wastage. There are other selective herbicides that are listed for use on wild onion and wild garlic – check the label to be sure. Always read and follow the label directions when using any pesticide.
Remember, one of the best ways to fight lawn weeds is to keep your grass thick, lush, and healthy through proper feeding, watering, and mowing. Here are some tips from the Viettes.