A bountiful summer garden depends on good preparation and planting in the spring. Understanding the local climate, good seed selection, soil fertility, starting seeds properly and good plant spacing make all the difference between a "green thumb" plot, or a sparse harvest. The good news is that getting a proper start takes no more time and effort than forging ahead without taking the time to be informed.
Know your Zone
Seeds sprout only in specific temperature ranges. Some plants will die at the first hint of frost, while others will become bitter and bolt if the weather's too hot. To learn about your climate's average yearly extremes, and the likely last frosty morning of the year, first find out your USDA Plant Hardiness Zone. Sunset Magazine also maintains a map of zones with descriptions of the general types of plants that do well in your area. For even more detail, like the average daily and monthly temperatures for your region, enter your zip code at a weather website like Intellicast.com.
Whether you're buying seeds online, from catalogs, or in local nurseries, read the packages carefully. Now that you know your local climate, you can predict the success of the crop from the cultivation instructions. For instance, you can assume cabbage isn't going to grow huge in USDA Zone 9 or above because cabbage likes long, cool days, and lots of them to fully mature. Likewise, some varieties of melon won't become edible before the first frost in short-seasoned zones. Save yourself grief by buying seeds that will grow well in your area.
Plants derive their basic energy from the sun in a chemical reaction with water, so both of those are important, too, but the soil contributes the essential minerals that ensure a healthy plant and good yield. Since plants take these nutrients out of the ground, it's up to you as a gardener to put them back in. Of the 17 or so elements identified so far as being useful to plants, three are the most crucial: nitrogen (N), phosphorus (P) and potassium (K). You can either buy commercial fertilizers, or replenish the soil much more cheaply by composting with inputs that are generally free.
Scan that seed packet one more time, and follow the germination instructions. Some plants can get a jump-start on the season by starting indoors before the last frost date. Other plants don't transplant well at all and need to be direct-seeded in the ground when the weather is at the right temperature.
It looks wasteful at first to transplant seedlings as far apart as the instructions insist, but just like a puppy with big paws, these plants are going to get a lot bigger. If they're crowded, they may get too discouraged to produce much. Thinning direct-seeded plants can be a painful experience for the gardener who wants to nurture and not destroy, but the overall yield will be better with the fewer who have the room to thrive.
Now that your plants are off to a good start, the only work left is to keep them hydrated and reasonably weed-free until the harvest.