Even if we have the feeling that only in our garden we have lots of weeds, practically in any garden the soil is full of weed seeds and fragments of perennial weed roots. Weed seeds are brought into our garden from neighboring land by the wind and in the soil or compost around bought plants. By cultivation we disturb the soil and bring weed seeds to the surface where they are able to germinate. Soil cultivation also allows small pieces of perennial weed roots to regenerate and start a new growth cycle over again.
So it is impossible to clean a soil completely of weeds, but regular weeding, rather than sporadic attempts that are then followed by periods of neglect, is the best method of control. One of the most effective methods of controlling weeds is tedious, hand-weeding, using a hand fork, since by this method you can ensure that the whole plant is removed from the soil and this method also causes the least disturbance to existing plants.
Hoes are used to remove annual weeds and also help to aerate the soil. You have to use them carefully or else you may damage the surface roots and top-growth of nearby plants. Hoeing mainly affects the surface soil and seldom goes deep enough to destroy the roots of perennial weeds. For perennial weeds you have to dig them out or to destroy them using a translocated weedkiller.
Where is a garden there are weeds too. Weeds can be controlled by manual means: hand-weeding or hoeing, by physical methods: smothering under a mulch, or by using chemical weedkillers. There are few things that you should consider when using weedkillers. Also consider that well-established weeds may need several treatments or prolonged persistence to eradicate them.