There was a time not too long ago when the prevailing wisdom of all new allotment holders was to kill off all vegetation on a plot as they prepared for new plantings. While certainly effective and efficient, this practice has now fallen out of favor because it also kills off potentially helpful insects and micro-organisms in your plot’s soil. New allotment holders are now encouraged to be much more selective in their weed killing practices. Because there are so many different weed killing products available, the basic descriptions below will be useful before making any purchases. If needed, a garden center expert can provide additional information and suggestions.
Systemic weed killers
Also known as translocated weed killers, this type of weed killer is akin to setting off a nuclear bomb on your unwanted plants. Systemic weed killers work like this: 1. Spray the unwanted plant’s foliage, 2. The plant’s foliage absorbs the chemicals and transports the chemicals all the way to its roots, 3. The plant dies completely from leaf-tip to root. Because it is so effective, this method of killing plants should be used sparingly and as a spot-treatment only. Any chemical that gets on neighboring plants will kill those plants, too, so be careful about spillage onto other plants. Glyphosate is the most prevalent chemical in systemic killers.
Contact weed killers
As its name implies, this type of killer weed only kills on contact. Organic growers generally prefer this type of weed because it uses a natural fatty acid. This acid dissolves a leaf’s protective coating which, in turn, causes it to dry out and die. Another type of contact weed killing is one which uses a powerful chemical that affects only exposed foliage but preserves the roots. One would most commonly use this kind of weed killing on annual weeds. Most contact the chemical known as diquat as their main ingredient!
Residual weed killers
It would be best to completely avoid using residual weed killings. As one could guess, the name is derived from the fact that this type of weed killer resides in the ground and continues to be effective. This residual effect will kill any and all seeds that try to germinate or any perennials that try to grow. You may want to utilize residual bud killings to clean unwanted vegetation from driveways or paths, however, there’s not any place for this type of weed killer within an allotment. Residual killer weed commonly uses the chemical known as diflufenican.
Selective weed killers
This is a useful killer weed in that it ‘selects’ what to kill meaning that it kills individual broadleaf weeds but spares narrow-leafed plants like grass. Gardeners who want a grassy, weed-free lawn will want to use these selective weeds. Just like in the systemic killer weed mentioned above, selective weed also uses the chemical known as glyphosate.