How can I perk up my iris bed?? It is about 30 years old, but I thin it every 2 or 3 yrs.?

I know that you can add something to the soil . . . is it lime? If so, how much? TIA

How can I perk up my iris bed?? It is about 30 years old, but I thin it every 2 or 3 yrs.?
For this you need to give it plant food and put extra nutrients in the soil, look on the net and find plants that it likes and plant them next to your Irisis this will give the iris's a better chance, keep pests away and like I said put loads of nutrients in the soil, also take the Ph number and check to see whether it is that, because if your bed has been their for thirty years I should imagine a lot of the nutrients have worn out.
Reply:Make compost and add some every year to keep the soil tilth
Reply:This fall pull your iris' and add a lot of compost and a tablespoonful of bone meal under each one. They should do much better next year. Fertilize them when they start growing next year.