Most gardeners, even novices, know in which climate zones they live.  Those who are new to gardening or those who live on the fringes of climate zones may need to know.  The United States Department of Agriculture provides a map that helps to delineate the zones. The maps are periodically updated because climates change.  For example, in the U.S. Southeast, the line marking the limit of USDA Climate Zone 8 has moved southward.  The map has been edited accordingly.  It is one of the finest services that the U.S. government provides for us in return for our tax dollars.

While the data is very useful, it is not exact. Gardeners must keep in mind that the zone map only indicates average minimum and maximum temperatures. It does not consider humidity, rainfall and many other climatic conditions. In addition, gardeners must keep in mind that plants recommended for full sun to partial shade will probably tolerate full sun in the northern reaches of their adaptibility, but may require partial shade in the Southern areas.

To find your climate zone, search for the USDA web site and narrow your search to find your location.

Roto-till the top 12" to 18" of the area where you intend to plant. Add organic matter such as organic compost or peat at a rate of 25% by volume into the planting area. Sites with heavy clay should be amended with builder's sand and/or gypsum.

Many gardeners have found that tilling the soil exposes weed seeds and results in heavy weed infestations. This is particularly true for Southern gardeners. If your soil is not in need of amendment, you might consider not tilling.

Gardeners who do not need to till may simply choose to eliminate weeds from the planting site by applying a biodegradable herbicide. For areas with heavy weed-infestations, a couple of herbicide applicates two or three weeks apart may be beneficial.

In addition to compost, gardeners may find that it is beneficial to incorporate a complete fertilizer like 10-10-10 into the soil at planting time. A high nitrogen, slow-release fertilizer like 12-4-8, 16-4-8 or 14-7-7 should be applied at intervals of 4 to 6 weeks after planting beginning in early Spring through late Summer. Low nitrogen fertilizers, like 5-10-15 may be applied in early Fall and Winter.

I do not recommend weed-barrier fabrics, for the following reasons:

If used on slopes, they may not allow rainfall to "perk through" fast enough, so the water washes down the slope and carries almost everything with it (plants, mulch, etc.);

The water has to go somewhere. It may be caused to puddle where you don't want it, like at the foundation of your house where it can cause unexpected problems under crawl-spaces and foundations;

They may prevent weed seeds underneath from growing upward, but they do not prevent weed seeds germinating above the fabric from growing downward;

Sooner or later, they begin to degrade. Loose edges may become unsightly.

Pre-emergent herbicides incorporated into the planting area can be very effective. If you decide to use them, be sure to follow all label instructions.

Applications of mulch can greatly help in weed prevention and moisture retention.