Late this spring, I bought and planted two agapanthus (plural?) of the same variety along my driveway. One of them looks fine: dark green strappy leaves. The other, however, is looking a bit sad. Its leaves are paler, shorter, and some of them have turned black along the tips and then die off. I should have taken a picture to post; I'll try to do that when I get a chance.
Does anyone know what could be wrong with my agapanthus? I've looked around online, but it sounds as if they are almost bulletproof, so I don't understand. The underperformer is getting more sun than its friend. I don't know what to think. Should I just replace it?