Seed tapes are wonderful for plants that have specific planting distance requirements like beets, carrots, radishes, and onions. Planted and grown too close together, these vegetables can become stunted or misshapen. They're great for plants like lettuce, spinach, and chard that also have spacing needs. Seed tapes are designed to provide the necessary spacing with no need for thinning.
One of my favorite catalogs, Gardener's Supply Company, offers a number of effort-saving gardening tools and supplies. They sell three, five-and-a-half-feet long seed tapes for about five dollars (US). That's enough to plant two rows in a typical eight-feet-long planting bed. Assuming an average spacing of about three inches per seed, you should get about 70 plants per package. However, the selection of seed varieties is limited to just a few types.
If you're willing to spend the time and effort, you can make your own seed tape for a fraction of the cost, using recycled newspaper. You won't be limited by seed variety; you can choose any seed you like. And you can make them any length you desire.
Set the strip in a location where it can dry for an hour or two without being disturbed.
You can save a great deal of money by making seed tapes yourself. I purchased 250 beet seeds for $2.25, for an average cost of less than a penny per seed. The recycled newspaper and flour paste adds a few pennies to the overall project. Spacing them at three-inch intervals on a homemade seed tape, I can produce over 60 feet of beet seed tape for just over two dollars total cost. An equivalent length when purchased would be over $20.
Using seed tapes can be a good idea for very small seeds. When you sow on open soil, it can be difficult to see where the seeds land; you may miss the furrow completely. It can be tough getting the spacing right, so open sowing often requires using a lot of seeds and then thinning the plants because they end up too close together. Using seed tapes allows you to see exactly where the seeds are planted and ensures you have proper spacing, thereby limiting wasted seeds.
You usually don't need seed tapes for large seeds like squash, melon, and corn. For plants with large spacing requirements like tomatoes, cucumbers, or peppers, seed tapes aren't necessary either.
Seed tapes can be very useful for mid-season and successive planting without disturbing plants already in the ground. You can place a length of seed tape in between rows of other plants during the summer. As the initial plants are harvested, the new ones from the tape are beginning their growth. Many cool season seeds are planted at intervals so you have continuous harvest later on. Placing a new seed tape of radishes or lettuce at two-week intervals can give you a steady harvest with little effort.
If you haven't used seed tapes before, think about adding them to your bag of tricks. You can buy them or make them. Either way, they are a perfect, no-waste method of sowing seeds.