High-Density Container Gardening

By now, most Readers will have picked up on the fact that for the past couple of years I have been experimenting with growing pepper plants in containers as opposed to in the garden. The benefits of 'container gardening' are numerous, however they are not the subject of this article.

Most of the gardening references that I have consulted over the past few years specify a fairly standard plant spacing for pepper plants, to wit: 12 to 18 inches between plants (see Notes: Transplanting to the garden). Accordingly, I have always used a plant spacing of 15 to 18 inches when growing peppers in the garden.

Within the past year, however, I have obtained a reference that discusses using very close plant spacing with peppers to improve yields. The Pepper Garden (Ref 11) quotes Arthur Pratt, professor emeritus at Cornell University, as saying "...pepper plants grow almost twice as tall when they're tightly spaced, and then there's usually less sunscald on the fruit because they are better shaded by the leaves" (Ref 11, 108). Professor Pratt recommended planting on one-foot centers.

Further, this reference cites the technique of a commercial pepper grower named Jeff Campbell of Stonewall, Texas, who uses plant spacings as small as 4 inches (Ref 11, 108-9). The authors note that close plant spacing, in addition to the benefits cited by Pratt, "helps to keep moisture under the canopy of leaves" (Ref 11, 109).

These benefits are essentially the same as those obtained by growing tomato plants in cages; further, the source of the benefits is the same in each case: improving the density and extent of the leaf canopy. Given this parallel with a technique with which I am familiar, reduced plant spacing sounded like it was worth a try.

I decided to try combining the high-density technique with container gardening. I made two 27.5 gallon planters by cutting a black plastic 55 gallon drum in half and drilling a number of 3/4" holes in the bottom of each planter for drainage. First in was a 2" layer of coarse gravel, again to help the soil drain. It took about 200 pounds of soil mixture to fill each planter most of the way- for each one I used a well-mixed blend of 160 pounds of bagged Topsoil and 40 quarts of Majestic Organic Soil Conditioner. Obviously the result is a very heavy planter, so it is best to put it exactly where you want it *before* filling it up with gravel and dirt.

I planted nine plants in one, and eight in the other; in each case eight plants were transplanted in a circle so that each plant's stem was 4-5 inches from the wall of the container. This provided plant spacings ranging from 4 to 8 inches. In the first planter, the ninth plant was transplanted to the center of the planter.

Both of the planters got morning sun, and one of them got a bit of late afternoon sun as well. Watering frequency was about the same as for the pepper plants in single pots (every 2-3 days), but the amount of water required per plant was a lot less for the planters; the planters only got a half gallon each per watering, which is the same amount that the Tabasco plant got by itself.

The results were quite good; the plants grew together well and produced an excellent canopy. Most of the plants grew to appropriate heights, so the fact that they were growing in a crowded container did not seem to have a strong negative impact on their growth.

If you do not have a garden plot, and you do not have a lot of sunlit space available, I think that this would be a viable way to grow a number of pepper plants in a small area. I intend to experiment further with this technique next season.


Email a link to this page to: