@Wewereseeds@sunbeam.city
Trees that die out of a sudden is problematic, and you should look into it. They are quite an investment, in terms if energy, fertility and time, they should be there for a while. Still, I wouldn't give too many attentions to them, they should do fine by themselves.
Annuals or quick plants? Pff, I kill them as nothing, that's why I always plant a few hundreds more in the nursery.
Don't feel bad about it, they make good compost :)