Growing multiple pepper plants in one pot vs just one plant per pot

Question

I'm a real hot chili lover, and yearly grow about 50 plants from about 10 varieties. I'm used to grow 3 plants (of the same variety) in a single 40 liter pot. While I do get good results, I'm still not sure if it's a good idea to put multiple plants in one pot, or just grow one plant per pot.

Let's assume I can only place 10 pots of each 40 liters for space and maintenance reasons. Cost of seeds and germinating them is negliable as 10 seeds cost just max 3 EUR. Cost of potting soil is quite more expensive however, let' say 8 EUR per 40 liter. Would it be a better idea to only put 10 plants in 10 pots, or place 30 plants in 10 pots? Or would another setup be better? What would give the most return to investment, and why?

... EDIT ...

For illustration purposes, these were my plants last year:

21 may 2017: just placed outside (germinated in februari, first grown indoors as we can get frost until may here)

6 july 2017

A single picking of peppers (unfortunately I don't have any later pictures of the plants)

Close up of 2 satan's kiss and a 'peter' pepper.

Answer 1

As is often pointed out in books on small-space gardening, spacing recommendations aren't set to maximise yield per unit area, but yield per plant.

If 3 plants per pot works, carry on. You'll get more chillies this way than growing only 1/3 of the plants. You may be able to get bigger fruit by thinning them. You may need to water and fertilise more often than single plants in the same size pots.

But why not try an experiment: Plant a pot with 3, then a pot with 1 (all of the same variety A), then 3 of variety B in one pot, 1 of variety B, 3 of variety C etc. When you harvest, log how much you get from each pot (or even each plant) by picking into a different container for each pot, and weighing the fruit when you get them back to the kitchen. As chillies ripen over a long period you'll need to do this every time you pick. Growth/ripening rates may differ between the full and sparse pots. You can then also keep notes about the quality of the chillies -- you may want total weight (e.g. if making chilli flakes), but you may want the individual chillies to be big.

Answer 2

It's recommended that plants be separated in the ground by 20 inches. If you try that in a 40 litre pot you'll only get one plant per pot.

If you plant more plants per pot, then what's going to happen is that each plant will compete with the others so they'll be smaller plants with smaller chili's.

They say you can plant into 2 litre containers but they are then more fragile, easily blow over, and need more attention to watering and fertilizing.

https://www.thompson-morgan.com/how-to-grow-chilli-peppers

Answer 3

I would plant starts of peppers in tiny pots upgrading them as soon as the roots show through the drain hole. In a 5 gallon pot you could easily grow 3 pepper plants of a smaller stature. My Thai peppers were maxed out in 1 gallon pots. One per pot. I upgraded them from tiny starts in tiny pots to a slightly larger pot and again to a slightly larger pot and usually it's final pot.

Make dang sure your nitrogen is way lower than the phosphorus and potassium. Do not use compost or anything else other than potting soil for your peppers. If you start your starts in tiny containers with potting soil and upgrade them as their roots maximize the pots...when they are in 6" pots up to 2 gallon pots per plant you will have the best crop as long as you've given them just enough fertilizer that is lower in Nitrogen than Phosphorus and Potassium, lots of sunlight out of doors, water when dry only...you'll get tons of peppers.

Answer 4

I wouldn't advise planting different types of pepper plants in the same pot. Not that it can be harmful to anyone or any of the plants! However, the outcome would be better if they were planted separately.