Over the years, we've gravitated to planting the majority of our peppers in pots. We're a small-scale grower, usually growing around 50 plants or less in a given year. If that's you, then here's a few reasons why we like to grow peppers in pots...
Though, doing them in pots does come with a few drawbacks...
If grown in a container, the container's size (and sunlight) will generally be the limiting factor in keeping a plant from reaching its potential. Additionally, when planted in too small of a container, pepper plants become root-bound and require very frequent watering.
Typically, your garden store or seed seller will recommend a minimum planting distance based on variety that ranges from 2-4 feet. Use the table below as a guide to convert spacing to a proper pot size.
We typically add straw (or lawn clippings) and homemade compost to the potted plants. The compost provides many nutrients near term, while the straw/grass will decompose over time to give the plants an extra kick in the longer term. It's also beneficial as straw is cheap and the compost is free. Doing this reduces the amount of potting soil we need to buy. As the straw decomposes, the soil level will drop. When completely consumed (in about 1-2 months), you can add another batch of compost and soil to top off your container if desired.
This year, we experimented with buying our soil in bulk from Soil3. We mixed the 27 cubic feet of organic soil they provide with 6 cubic feet of peat moss and 4 cubic feet of perlite, saving a total of $65, or 21%, compared with buying potting soil by the bag. The peat moss helps to lower the soil's pH, making it more acidic, which is good for pepper plants. The perlite helps to improve drainage, capture oxygen and keeps the soil from compacting too much. Not only did this save us money, the quality of the soil was much improved and it saved multiple trips to Home Depot for what would have been 22 bags of potting soil.
Using the above ingredients, we build our pot as follows...
We like to put the straw and compost in the middle layer so the plant grows down to it and to reduce weeds and other volunteer plants that would inevitably sprout from the straw and homemade compost. We also bury the bone meal at the compost/straw layer and below. We've found that putting the bone meal at the upper layer tends to attract animals that will dig up the soil and potentially (usually :/) damage young plants.
Previously after a growing season, we'd empty our pots into our raised beds and use new potting soil the following year for our potted peppers. This annual flush-and-refill is a decent amount of work and a significant expense.
The soil3 website claims that its soil has enough nutrients to last up to 4 years in raised beds without fertilizer. Using their soil this year, it does appear to be high quality soil and we'd like to see if we can reuse the same soil next year.
Though, we're going to give it some help in an attempt to replenish lost nutrients. With the initial straw and compost layer, our pot's soil level has compressed significantly through the growing season, leaving the top 1/3 of the pot empty. After pulling the plants this Fall, we're going to fill that top layer with compressed straw, compost, bone meal and rock dust. After which, we'll top off with a couple of inches of soil as a weed barrier.
By Spring, this should return most of the nutrients lost last year. Our main concern with soil reuse is it may allow small amounts of mosaic virus to remain in the soil and more easily affect next year's plants. We'll plant some control pots to test.