Spacing of plants in containers?

Started some seeds indoors that will be in outside containers. Spacing suggestions listed on the seed packets are for planting in the ground. For example, sweet banana pepper (grows 24" high with 6"peppers) space in garden 18" apart. I was going to try these in a window box planter (about 2' long) but set on the ground. Got a lot of Italian basil seeds going in another same size window box, some flowers for other small containers as well.

- How close spaced in a container is still good?
-Are there general rules (based on height and width of grown plants) or all different depending on variety?
- Is overcrowding a problem?

I think it depends.The reason for spacing plants is so they can reach their full potential.Plants have to compete for sun,water and nutrients.In a container you can control it somewhat better.You can tell after a while,if you have overcrowding.Lets say you had 10 basil plants growing in a container.5 were huge,3 were medium and 2 were puny.I would pull all except the 5 huge ones.Survival of the fittest.Its natures way and a little of your intervention.Edge

If you think about the two ft' planter this way. It is 24" long but it is not 18" wide so the space is really for one plant. If you want to try 2 anyway then see how they grow. If they aren't doing good then you will need to remove 1 or you may not get any peppers or you may only get very puny ones.This is the same thing Edge was saying. There is a reason for the spacing on any plant.

i always plant my vegetables in 5 gallon containers. you cn only put one tomato plant in ech container and one pepper plnat. i have tried putting two pepper plants inside the container but they didn';t do to well.

as far as basil is concerned i sow 4 seeds in a 4 inch container and put maybe two 4 inch containers into the 5 gallon container and they do very well. i'm talkingabout 8 basil plants into the 5 gallon container.

I think that space between rows is mostly to give access for weeding and harvesting. In pots (and to some extent in raised beds), I usually use the "thin to" spacing as a guide in both directions. Containers also introduce the variable of soil depth, which is not an issue with ground based plants.

Most basil grows well in half height pots. I find one plant (standard, patio, or windowbox) per 8", half-height pot does very nicely. Lettuce also grows well in half-heights. Plant 1 lettuce per 8" for head lettuce (romaine, buttercrunch). Random scatter/dense pack mesclun and cut-&-come-again varieties. The solid wall of lettuce saves on weeding. 6 or 8 radish will also thrive in these pots. Onions also need little soil. I planted green onions today. Pack said thin to 1 inch so I planted them 1 inch apart: about 40 seeds in each broad shallow pot.

In normal height pots you can dense pack dill, cilantro, and parsley. Follow thin to guides for carrots, and so on. Cherry tomatoes and peppers do nicely in a 10-12 inch pot (3 gallon?) for each plant, while heirloom varieties prefer a bigger 14" (5 gallon?) container, as do cucumbers provided you cage or stake them. Really big tomato varieties and most squash don’t do well in any container for me, but perhaps others have better luck.

Ed

BTW... Basil are excellent companion plants for tomatoes, so a basil or two on the sunny side of each tomato pot usually benefits all the plants.

Maybe there are some exceptions, but spacing recommendations that are on seed packets are generally just the spacing that the plants need to not be crammed on top of each other, they're not going to assume that you're planting in rows and need to walk between them. If you look at the example in the first post of the peppers that are supposed to be planted 18" apart, there's no way that's allowing for the width of the plant plus an area for you to walk in, that's just the space the plants need so that they're not crammed together.

I just checked a few of my seed packets. Burpee peppers recommend 18" between plants but 36" between rows. American seed onions want 1" between plants, but 18 inches between rows. Botanical Interests carrots require 2" between plants but 12" between rows, and so on. Most of my packets seem to demand an extra 18" or so for row spacing... However, Rene's Garden and Seeds of Change do not make a suggestion for row spacing, so my assumption that every seed packet had the fudge factor was clearly wrong. Thanks for pointing it out.

That would make sense if some of them list both row spacing and between plant spacing--I just couldn't imagine a seed packet only listing the row spacing without the plant spacing since even if you plant in rows you still need to know the correct spacing between plants in the same row. So if it only gives you one number, I'd assume it's the spacing between plants.

Space between rows assumes mechanical cultivation.

Square foot gardening wisdom is that whatever it says between plants, that's the space you need on all sides. So if it says 18" between plants, you would put one plant in an 18" square.