How do you feel if this happens?

Say you buy three of the same plant. Say a heather. Things always look better in 3s, the effect is stronger.

But one dies. So you're left with two.

If you cant remember the exact variety/cultivar, would you use something really similar? Does it really matter that much?

I'm trying to decide if just having two would look worse than having one with a very very slight difference, next to two others.

 

As long as it’s the same or a similar colour I wouldn’t worry. I’m often replacing or relocating Nepetas and forget which varieties they are.

 

Wouldn't bother me, plants are plants.

 

Most of our garden plants can be fairly easily propagated so I always take cuttings/ divide clumps just in case.

To be honest, that's not always the best policy as I'm unable to get rid of the surplus so often end up with not a neat threesome but with a thirteensome

Obviously, the propagated one will take time to reach the same size as the two original members of the threesome but with permanent plants that's not a big issue.