After a new landscape is installed or the ground is disturbed weeds will likely be an issue. Within days of a new installation new weeds can begin to show. You will want to deal with this quickly and often, no less than monthly, before these weeds establish themselves through root systems or go to seed. Preferably these weeds will be sprayed with a non-selective herbicide which will kill the entire plant. Granular pre emergent herbicides can also be used before yearly mulching to help prevent weeds. Initially the weed load will be high but with the right program the weed load will diminish over time getting noticeably better each year over several years of regular maintenance.
Yearly mulching is a very important part of weed control as well as providing vital protection to the root systems of plants. Mulch in direct contact with the soil (NO FABRICS) will passively and organically fertilize your landscape and greatly improve your soil structure even in the poorest of soils. It is important to add 1-2” of fresh mulch on a yearly basis which not only makes your property look great but it replaces the amount of material that earth worms and micro organisms consume and pull into the earth over the course of a year. I like to see mulch like a three layer cake in cross section. After 3 years of mulch and soil contact, the bottom inch of mulch applied 3 years ago has mostly been broken down into high grade topsoil and organic matter that is being turned into fertilizer and amended soil by biologic activity, the middle section applied 2 years ago is well on its way to being broken down and is the transition zone, and the top layer is fresh and less than 1 year in age and acts as your weed preventer.
We recommend using an organic bark or triple processed material rather than chipped, chunky mulches as the higher quality material will firm up creating a surface crust that is erosion resistant and also makes for a great and completely natural weed barrier. There is a saying that goes “an ounce of prevention is worth a pound of cure”. I’m not sure who said it first but it is very true and especially so when it comes to mulching and weed prevention.