At first glance, planting instructions for flowers and vegetables seem simple enough, whether the source is a book, the Internet or the back of a seed packet. Supposedly, these instructions tell you everything you need to know to grow a particular plant. But instructions can sometimes be so simplified as to become almost meaningless.
Take a packet of lettuce seeds for example. The instructions say to plant in average soil in full sun, spacing the seeds four inches apart in rows that are 12 inches apart.
But what is "average soil"? "Full sun"? Is this spacing mandatory? What if you want to plant in wide rows or in blocks? Master gardener Paul James offers this advice on how to interpret planting instructions:
"Full sun" is generally understood as being at least six hours of sun a day, something you're likely to experience in a garden that faces mostly due south or southeast. Most flowers and vegetables need at least that much sun a day to grow properly. Some, such as peppers and tomatoes, prefer even more. Others, such as lettuce and dogwood trees, do better with less.
This definition and other terms such as "partial sun" and "partial shade" also depend on latitude and climate. Full sun in Texas is a lot more brutal than full sun in Montana, especially during the summer. Tomatoes in Texas may scorch after six hours of sun, while the same tomatoes in Montana may need at least 8 to 10 hours of sun. If you're growing something for the first time and you're not sure how to interpret such terms in your area, use your own best judgment or consult your local extension agent or nursery experts.
"'Average soil' — there's a phrase that leaves me completely in the dark," says Paul. "It's downright undefinable, and I have no idea what it's supposed to mean. 'Average soil' is taken to mean something in between pure clay and pure sand. That's great if that's the kind of soil that everyone has, but it's not, which means there's no such thing as average soil." There are an infinite variety of soil types across the country like sandy loam, silty clay, pure clay. If your lot has been regraded, you may actually be trying to garden on fill dirt.
"What the instructions should call for is 'improved soil'," says Paul. "No matter what shape your soil is in, chances are there's room for improvement."
"Recommended spacing requirements for most plants are so outdated as to be useless," says Paul. The lettuce seeds don't need to be spaced four inches apart in one direction and one foot in the other. The spacing requirements date back to a time when gardeners laid long, straight rows so that they could walk (sometimes with a tiller) in between.
Lots of people, including Paul, rarely plant in straight rows today. He plants in wide rows so that he can cram a lot more of a given crop into an area. If you plant in wide rows too, pay attention only to the distance between plants, not to the distance between rows. If the suggested spacing between plants is four inches, then that's how far apart the plants can be spaced in any direction.
If your soil is fertile, you can pack even more plants into the bed. For example, if the instructions call for four inches between plants, try three. That way you'll get 25 percent more out of the same amount of space.
To safely use the seed-package instructions, factor in the kind of soil you have. If the soil is mostly sand, plant the seeds deeper, and maybe even up to twice as deep as the package recommendations. If your soil is mostly clay, you may want to just barely cover the seeds.
But how do you cover seeds with a quarter-inch of soil? Paul has two methods:
- Use a metal garden rake to create small, evenly distributed holes over the planting area about 1/2 inch deep. Then scatter the seeds over the area. Next, gently rake across the area, which causes a fair amount of soil to fill the holes. Finally, lightly tap the entire area with the end of the rake to ensure good contact between the soil and the seeds.
- Or, you can simply scatter the seeds over the prepared planting bed. Then fill a sieve with garden soil or sifted compost and shake the sieve over the seeds.