The short answer to “how close together should I plant succulents,” really depends on your goal with the arrangement. First, let's talk about tightly planted arrangements.
Something interesting about arrangements planted close together is that those succulents don't grow as fast because there isn't room for them to grow and spread.
A tightly packed arrangement like this is going to keep its shape better; it's not growing as much, and thus, the arrangement will look better, longer.
Generally, an arrangement like this looks prettier and more finished, so it's a great technique when you're gifting or selling succulents as an arrangement.
A few downsides to planting succulents close together is that it makes it harder to water, and actually get the water down to the roots.
A great solution to this problem is to use a watering can that has a really small spout, and push it in between the leaves of your succulents to get down to the roots.
Granted, you can pour water directly over the top of the arrangement, but I've found it's helpful to get between the leaves to water, to make sure the roots are getting wet as well.
Another downside to planting succulents close together, is that when the do grow, eventually they just look way too big for the planter. At that point, it's hard to trim and remove them because they're so tightly bound into that pot.
A lot of times, they're also root bound, meaning the roots are filling up most of the pot or planter that they're in.
Again, there is a work-around for this. You simply pull everything out of the pot and use scissors or a sharp knife to cut through the roots and break things apart.
It will take awhile for the arrangement to get to that point, so you can try and prune and maintain it beforehand. Keep in mind that if it does get too overgrown, it will be more difficult to pull those succulents out and refresh the arrangement.
Now let's talk about some reasons why you might give your succulents a little more room to grow.
As you may have guessed, a lot of the pros and cons for planting succulents farther apart are the opposite of planting succulents closer together. One of the biggest advantages to planting your succulents a little more spread out is that they will get bigger faster.
If you're not as concerned about how tight the arrangement looks, and how perfectly planted and all close together everything is from the get-go, then this is a really good option.
Your plants will get bigger, and they're also more likely to put off babies or have new growth because they have the extra space to do so.
You'll also find that you won't have to maintain the arrangement as often. There's more space for them to grow, so you won't feel the need to cut back or remove parts of the plant to allow the arrangement to look like it's filling up the space nicely.
If you do decide you want to do more maintenance on your arrangement, it will be a lot easier in this spread-out arrangement because you'll have room to put your hands or some scissors in, to do some cleaning, pruning, or trimming.
It's also easier to water this type of arrangement, and to make sure the roots are getting soaked all the way through. Whether you're pouring water directly on top of the plants, or below the plants directly to the soil, you'll be able to get water to the roots a lot easier.
There are some downsides to planting succulents more spread out. One of the biggest is that the arrangement doesn't look as full or impressive right away. A great way to combat this is to use a top dressing, or decorative rock. You can put down a really pretty rock between all of your succulents, and it helps things look finished and more professional. The great thing is, this own't prevent your succulents from growing, and really just helps the arrangement look better.
Another downside to planting your succulents farther apart is too much rooms will cause the succulent to put out roots, and you won't see as much growth in the succulent itself initially.
A good amount of space for your succulents is generally about 1/2 inch to an inch (13 mm to 25 mm), whether you're planting them with other succulents, or in a pot. Give them about 1/2″ between the edge of the pot or any other succulents.
The last downside might not really be a downside, but with those gaps between those succulents, you might be include to buy more succulents and fill in the gaps!
But that's not really a downside, right? Then you just have more succulents!
Really all of this boils down to, how much care do you want to put into maintaining your succulents, and whether or not you want your arrangement to look the same as when you first got it, or when you first planted it.
As a general rule, if I'm planting succulents for myself, I spread them out a little bit. I want them to grow, I want them to put off new babies, and I want them to have some space.
I'll use a top dressing in between the succulents to keep things looking tidy and professional, but still giving the plants room to grow.
On the other hand, if I'm giving succulents to someone, or putting together a project that's going to be displayed somewhere, I'll usually pack them in a lot more tightly.
This way, the person receiving the arrangement won't have to worry about doing maintenance on the arrangement for quite some time.