This article will assume that the prospective gardener either owns or can rent a garden tiller and knows the fundamentals of operating one. The best time to till your garden is is dependent on whether you are beginning a new garden or have to till land that has already been cultivated. Both cases will be examined in turn.
Beginning with a fresh plot is an exciting prospect for any gardener, and a lot of headaches and problems which may occur in future can be minimised if the initial tilling is done with care and attention. A new plot is best tilled in mid to late spring. There are many reasons for this. Firstly the weather is likely to be more favourable. The soil, though moist will not be sodden and the tiller will be able to break up the soil more easily. Heavily sodden soil can easily clog up the blades of a tiller, hampering their efficiency. By waiting to the middle of spring the gardener will be able to spot any perennial weeds, such as dandelions or nettles, that are growing on site. These must be dug up before tilling and the roots removed. Tilling these plants into the soil is not advisable, as the tiller will cut the roots into many pieces, each of which has the potential to grow into another plant. Although delaying this process until late spring will delay any subsequent growing season, removing the maximum amount of pernicious weeds possible will help immensely in seasons to come. At the same time as tilling the soil remember to add in as much organic matter in the form of compost or well rotted manure as possible, as this is all an investment in the future of the garden. This is also the best time to remove any large stones from the plot, those above ground before tilling. Unfortunately you will find those below ground as you till.
Of course people may move into a new house at any time of year and want to make a start on the garden. You can till your garden at any time of year, but usually patience is rewarded in the long run. The middle of winter is often wholly impractical with waterlogged or frozen ground. The middle of summer may bring parched conditions and rock hard soils. Autumn presents the next best opportunity for the new plot and the same initial procedure as for spring should be followed, although the addition of organic matter can be done as in the next paragraph.
A plot that has been cultivated before and has produced a summer crop is best tilled in the autumn. Once the last remnants of the harvest are removed the soil can be tilled. Now organic matter can be spread over the surface and will be incorporated into the soil by the natural actions of earthworms and other soil dwelling organisms over the coming months. In this instance there is no need to add the organic matter as you till. Another advantage to autumn tilling is the fact that the soil surface will be further broken down by the action of frost over winter. This helps to produce the kind of fine tilth, (a fine crumbly soil surface) that is ideal for spring sowings. The fact that the soil is already prepared come the start of spring enables the keen gardener to remove any weed seedlings and sow and plant as early as possible, thus extending the growing season. With all the heavy work out of the way before Christmas it is easier to look forward to the start of the gardening year.
Once a garden has been cultivated for a period of time the use of the tiller should be minimised. The addition of more organic matter in the form of mulches each season will produce a rich and productive soil which will require less and less mechanical intervention, whether with tiller or spade. As with all gardening advice the reader must apply these general rules using commonsense and with regard to their own particular conditions.