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Wild Onion & Wild Garlic

In the early spring here in the mid-Atlantic region, I started to see some common weed activity.  What is very visible this time of year is wild onion and wild garlic.  Wild garlic (Allium vineale) and wild onion (Allium canadense) are winter perennials.  They emerge in late fall from underground bulbs and grow through the winter and spring.  In late spring, aerial bulblets are formed and the plants die back in early summer.  The underground bulbs can persist in the soil for several years.  While both have thin, green, waxy leaves, those of wild garlic are round and hollow, while those of wild onion are flat and solid.  Oddly enough, the garlic smells like onion and vice versa.
 
Mowing will not kill wild garlic or wild onion.  However regular mowing can weaken the plants and prevent them from setting seed.
 
Unfortunately, there are no pre-emergent herbicides that will control wild onion or wild garlic.  They must be treated with post-emergent herbicides.  Perseverance is the key.  These plants will need to be sprayed more than once and for more than one season.  One trait that makes control difficult is that both have a slender, shiny leaf to which herbicides don't readily adhere.  Unlike most weeds, mowing wild garlic or wild onion immediately before applying an herbicide may improve uptake.  After application, do not mow for at least two weeks.
 
Treat wild garlic and wild onion in November and again in late winter or early spring (February or early March) before these plants can produce the next generation of bulbs.  However, be careful not to apply most weed killers onto Centipedegrass or St. Augustinegrass during their spring “green up” period.  Inspect the lawn again in the spring and the next fall, and treat if necessary.
 
Imazaquin, the active ingredient in Image Nutsedge Killer, will provide control for wild garlic and wild onion.  N.B - This product should not be used on fescue and should not be applied to warm season turf during green up in spring.  Wait at least 1 & 1/2 months after treatment before reseeding, winter overseeding or plugging lawns.  This product is not for use on newly planted lawns, nor on winter over-seeded lawns with annual ryegrass.
 
Three-way broadleaf herbicides containing 2,4-D, dicamba and mecoprop (look for any or two or all three in a spray) will provide control of wild garlic and wild onion with repeat applications. Examples of these products are Bayer Advanced Southern Weed Killer for Lawns, Spectracide Weed Stop for Lawns – for Southern Lawns, Lilly Miller Lawn Weed Killer, Southern Ag Lawn Weed Killer with Trimec, and Ferti-lome Weed-Out Lawn Weed Killer.  These products can be used safely on most turfgrasses, but reduced rates are recommended when applying to St. Augustinegrass or Centipedegrass.  Apply during November, very early spring, and again the next November for best control.  N.B. - Do not apply these herbicides during the spring green up of warm season turfgrasses, or over the root zone of nearby ornamental trees and shrubs.  Do not apply these products to newly seeded grasses until well established (after the third mowing).  Treated areas may be reseeded three to four weeks after application.  Always check the product label for rate of application and to determine that it is safe for use on your species of turfgrass.
 
Metsulfuron (such as Manor and Blade) is an herbicide which is packaged for landscape professionals and gives very good control of wild onion and garlic.  Due to the cost of these selective herbicides, it may be more economical to hire a landscape professional for weed treatment.  Metsulfuron can be used on Bermudagrass, St. Augustinegrass, Centipedegrass, and Zoysiagrass.  
 
The addition of a non-ionic surfactant (such as Southern Ag Surfactant for Herbicides) may be a good idea too.  It is required at 2 teaspoons per gallon of spray mix for best control.  Read my blog post on "Wetting Agents".  A non-ionic surfactant will help the herbicide adhere to the leaves for increased penetration.  Do not apply Metsulfuron to a lawn if over-seeded with annual ryegrass or over-seed for 8 weeks after application.  Do not plant woody ornamentals in treated areas for one year after application of Metsulfuron.  Do not apply Metsulfuron herbicides within two times the width of the drip line of desirable hardwood trees.
 
Glyphosate, the nonselective herbicide found in Roundup Original, Eraser Systemic Weed & Grass Killer, Quick Kill Grass & Weed Killer, Bonide Kleenup Grass & Weed Killer, Hi-Yield Super Concentrate Killzall Weed & Grass, Maxide Super Concentrate 41% Weed & Grass Killer, and Southern States Grass & Weed Killer Concentrate, will also provide control of wild garlic and wild onion.  If you are unable to prevent glyphosate from getting on desired actively growing grasses, a selective herbicide should be used.  To do the least damage to your turfgrass, apply glyphosate only to warm season grasses during winter, when they are completely dormant.  However, during mild winters, the turfgrass may not be completely dormant.  I recommend not messing with a non-selective herbicide like glyphosate.
 
One answer to these weeds in flower beds and high-quality lawns is some smart pulling.  Sometimes they are tough to pull.  The entire clump should come out easily when pulled gently but firmly after a good, soaking rain.  This is one of the many benefits of improving your soil — weeds that sprout out of nice, loose, rich soil that contains a lot of organic matter practically pull themselves out. Conversely, weeds that grow in lousy, compacted clay are usually firmly anchored.

Pulling from wet soil is always more productive than pulling from dry soil.  So go out after a rain, reach down to the soil line and tug gently; that's how you get the underground bulb out completely.  If you only snap them off at the soil line, the plant is not harmed; you spend the same amount of time and energy as someone who does it correctly, but get no benefit.  Personally, I have about a 50% success rate each time I go after these weeds by pulling them in wet soil.  But, over time, they will be eradicated.

You can also remove tight clumps with a sharp, long-handled “poachers spade”, which is also a very useful tool for transplanting bulbs, plants and rabbit hunting in Merry Old England.

Single sprouts are the most annoying and time-consuming to deal with.  If you have a large area with mostly single plants, clear small sections at a time, being sure to pull slowly and get the bulbs completely out.  Start with highly visible areas and give yourself several seasons to do it all; if you've been cursing them for the past five years, you can't expect overnight eradication.  And don't let the un-pulled plants in other areas set seed while you're doing this; mow or weed-whack the tops off those miscreants before they can procreate.
 
I really don’t see wild onion and wild garlic as a great threat to the safety and security of your turfgrass.  I mean, it can get out of control.  Just like everything else, if you stay on top of it, little by little, it will go away.  You know how I am about consistency.  These weeds do violate my consistency standards.  And, you have to be careful about any applications.  See where I underlined a couple things.  Stick to it and you will be victorious.
 

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