Different weed control methods are needed for varying situations. Annual weeds growing in a small flowerbed, for example, can simply be pulled up. While sometimes, prevention is better than cure, as in the case of spreading organic mulch on the soil to prevent the germination of weed seeds.
Occasionally, such as when replacing a perennial lawn with ground cover plants, applying a systemic herbicide such as Roundup, may be necessary, albeit reluctantly so. There is one particular situation though, where allowing the weeds to grow under controlled conditions is actually preferable to eliminating them altogether by use of a weed killer.
This can apply to unplanted areas of the garden, which for one reason or another have yet to enter cultivation. It could range from a small space to be turned into a herb garden, a large area designated as a collection of fruit trees, or a complete garden plot. In cases when the area is not to be planted now but in the future, it is best to control the weeds by mowing them now and again.
Periodic mowing, either with a lawnmower or a mechanical strimmer, (weed whacker) prevents the weeds from flowering and setting seed, thereby keeping their spread under control. What is to be gained however by this instead of getting rid of them entirely? Where is the benefit in permitting them to grow, albeit under controlled conditions?
The question could also be asked as follows: “What is wrong in keeping the area clean of weeds altogether?” After all, there is no shortage of means, to achieve that purpose. Periodically spraying with an appropriate herbicide, for instance, will do the job efficiently and cheaply. The answer lies in the fact that the future health and fertility of the soil depends largely on it being protected from erosion on the one hand, and on the percentage of organic matter that it contains, on the other.
A soil that is “clean” of weeds is an exposed soil, meaning that it is subject to wind and rain erosion. One of the most important roles of plants, whether they be weeds or otherwise, is to hold the soil, preventing its top layer, which is its most fertile, from being washed or blown away by rain and wind. That is why steep gradients on the public highway, landscape projects, are planted up as early as possible.
Secondly, the build-up of organic matter caused by the life and death of weeds, improves the soil’s ecology, by improving its physical structure and enriching its fauna and flora. This has enormous implications for future pest and disease control, the fertility of the soil, and therefore the future health and vitality of the garden plants.