There are a few persistent weeds that don’t respond to the weed control available in Ontario, although this may seem discouraging, there are ways to manage these problems to reverse their spread.
Creeping charlie, a.k.a. ground ivy, is a tough broadleaf weed because of its resistance to iron-based weed control and its vigorous ability to spread. Creeping charlie “creeps” along with lawns with its low to the ground vines; it can usually be found in shady damp areas where turf is not as persistent.
Although online recipes for DIY borax solutions can give you a competitive edge, this practice should be done with caution as excessive boric acid can be damaging to turf, inviting other weeds over time. Practice proper mowing & watering techniques, trim back trees where they cause excessive shade and choose the right turf seed for the area. With proper turfgrass fertilization and proactive iron-based weed control combined with the right water and shade management, you can see a reduction of Kingston’s toughest creeping weed.
Wild violets much like creeping charlie have low responsiveness to iron-based weed control and again, they are found in damp shady areas of the lawn. The difference is that they have a rhizome instead of a creeping root system, and they spread well by seed.
Just like creeping charlie, to get rid of violets you’ll need to make sure you are following proper mowing and watering techniques. Early spring during flowering and in the fall are good times to focus your weed control efforts, these are times when the weeds are not growing as actively.
Bird’s foot is a common Kingston weed, it does not respond to iron-based weed control. It persists in hot and dry areas, you can often see city boulevards blooming yellow in early summer while surrounding grass is browning. On smaller lawns, the best way to manage it is by hand pulling, it tends to grow in bunches –easy for grabbing a handful.
Because this weed grows so well in dry soils, it is highly recommended that adequate water is supplied to surrounding grass to discourage persistent spreading. Bird’s foot is in the legume family, just like clover, so it can get plenty of nitrogen(fertilizer) from bacteria in its roots whereas grasses cannot. Proper fertilization of surrounding turf will certainly help the grass to compete but fertilization alone won’t stop the weed. Luckily, a properly fertilized and watered lawn will rarely encounter a bird’s foot problem.
Crabgrass is one of the ugliest weeds in Kingston lawns, this is mainly due to the fact that it has thick horizontal bright green blades protruding from dormant, dry brown lawns. Luckily, crabgrass is an annual weed which means that every year, you have a fresh start at preventing this problem.
Crabgrass is one of Kingston’s toughest weeds because of improper management, yes it is invulnerable to iron-based weed control once it’s present, but prevention is fairly easy! Mowing at 3.5″ or higher has practically the same success rate as pre-emergent herbicides, combined with proper watering practices, crabgrass will never get the chance to start. Crabgrass is adapted to very hot and dry areas of the lawn, a strong organic fertilization program with added compost can certainly give your turf the competitive edge it needs in a hot dry summer.
These very difficult weeds to manage, including goosegrass, quack grass, bunch type fescue, bentgrass, foxtail, and nutsedge. I’d love to say that these weeds only grow in the extremes of wet to dry lawns, which may be slightly true but they can persist in any condition. You may find bentgrass at the ends of drain spouts and bunch type fescue around dry and hot edges of lawns but the reality is, these grasses can be found anywhere turf can be.
Despite these grasses being well adapted to growing anywhere, extremely dry soil, as well as soaking wet soil, can be an entry point, as with all persistent weeds of Kingston, be sure to properly mow and water your lawn so these invaders never get the opportunity. Proper fertility can greatly benefit your existing grass as long as it builds healthy soil (organic) instead of depleting it (synthetic + aerations) as poor soil always leads to these difficult weed problems.
I hope that it’s painfully obvious that these weeds never need to become a problem, it’s only when proper mowing and watering are neglected that we lodge these persistent weeds. Prevention is the most important aspect of a healthy lawn, but if you already have these tough weeds you can still reverse their presence with proper management, and especially with especially organic lawn care.