Alternating plants is not a good idea
A consistent theme of this column is that you should learn more from your gardening mistakes than from your successes. In fact, the reason I’ve accumulated a good bit of gardening knowledge over the years is because of all the mistakes I’ve made and recorded in my journal. By reading the appropriate sections of the journal before planning each year’s garden I avoid making those mistakes again.
Here is a description of one of my major gardening boo-boos, in the hope that you won’t make the same error in your landscape.
"Star Trek’s" Mr. Spock would certainly agree that alternating plants with different forms or colors is logical. It satisfies your sense of symmetry, and provides lots of interest because of the differences in form and/or color. Yet alternating plants often just doesn’t work.
A personal example — I planted a new bed with 50 red and 50 yellow daylilies. The varieties were chosen so they would bloom at the same time and continue to flower throughout the season. I alternated them in rows and staggered the rows (Diagram 1).
But the daylily bed didn’t work out that way. The young plants didn’t completely fill the bed, and against the background of mulch and soil, the red daylilies were barely visible (Diagram 2).
What I should have done was plant all one color instead of alternating the plants (Diagram 3).
Compare Diagrams 2 and 3. The all-yellow flower bed has much more visual impact than the bed with alternating colors, and this will only get better as the plants grow. So I pulled all the red daylilies out of this bed, and within a year the yellow ones grew large enough to fill the space.
Another example — You want to install a long screen to hide an unsightly view. Two different plants are chosen that have different forms and heights (Diagram 4).
Yet this doesn’t look like a homogenous screen to me, but more of a saw tooth arrangement that bounces your eye up and down along the row. And if a couple of the plants fail, the gaps are very noticeable (Diagram 5).
A better arrangement would be a solid line of the taller plants behind another line of the shorter plants. Then even if one or two plants fail the gaps would be less obvious. And this screen would be more functional and attractive because of the increased depth (Diagram 6).
Don’t make my mistake of alternating plants with different colors and forms. The result is almost always disappointing. Use solid blocks or rows of the same plant instead.
Jim Janke is an Extension Master Gardener Volunteer in Haywood County. For more information call the Haywood County Extension Center at 828-456-3575. © 2014 NC State University. Diagrams by the author.