The best results from planting seeds are achieved when the soil is properly prepared and the seeds are planted at the correct depth and spacing. These steps must be followed by careful watering, so that the soil remains uniformly moist but not wet. While this procedure is well known, one or more steps are often skimped on or missed with disappointing results. Just a little extra care taken at this stage can save work later and produce a bumper crop.
Start with Good Seeds
Make sure your seeds are high quality, from a reputable seed company. Seeds sold by hardware stores and big-box retailers are often carelessly stored and handled. The seed packet may look fine, but the seeds themselves may have lost viability from exposure to heat or dampness. All major seed companies offer their products online, and this is usually the best way to shop. Store seeds in airtight plastic bags or containers, in a cool, dry place.
Even the highest-quality seed will not do well in poor soil. Prepare the seedbed by covering it with about 2 inches of finely screened compost. Rake this in to mix it with the top 3 or 4 inches of soil. This will help the soil to retain moisture and plant nutrients. Rake the surface flat and smooth, and water it lightly so it is just damp.
Once a year send a small sample of your soil to a soil-testing laboratory for nutrient analysis. The results will tell you what your soil contains or lacks, and give instructions on what amendments to use. To locate a reliable testing laboratory, contact your local county cooperative extension service, which will be listed in the phone book. They will also give you guidance on how to take a soil test sample.
Planting Depth and Spacing
Good-quality seeds come in packets bearing lots of really useful information. Even if you are not usually a person who reads instructions, this is one time when you really should! Pay particular attention to the planting depth and two space requirements---the distance between seeds, and the distance between the rows. Take your time, because it is better to plant the seeds carefully than have to come back and do a lot of thinning-out later.
If you are unsure of the planting depth, a rule of thumb is to plant seed twice the depth of the seed's longest dimension. As a planting guide, mark the rows with string stretched between wood stakes. Straight rows are easier to keep free of weeds, and look better, too.
Marking the Rows
Never assume that you will remember what you planted. Mark every row with a wooden plant label. Write on it, with a permanent marker, the species and name of the seed. As a reminder, it's a good idea to add the date when you sowed the seeds.
Since the soil was slightly damp when you sowed the seeds, all you need to do now is gently firm the soil over the seeds and water it lightly. It is very important that you keep the surface of the soil uniformly moist---not wet---until all the seeds have germinated. If you allow the soil to dry out many seeds will die. If the weather is hot and dry, this might mean sprinkling the surface two or three times a day.
Seeds that were planted too close together will need to be thinned so each plant has enough space to spread its roots and leaves. It is best to do this by snipping off the unwanted seedlings with a sharp-pointed scissor. Pulling them out, roots and all, may disturb and damage the roots of the plants left behind.