Tough durable plants sooner or later have problems. One good example is the sagos. At one time they were the go to plants for accents in home landscapes. They were so valuable they would disappear during the night. But you have a hard time giving them away now due to cycad scale as pictured.
One plant we all thought would be pest free is the flax lily. It came on the landscape scene very quickly and has been used extensively. Within a few years we found plantings had scale insect problems and maybe even worst a rust disease.
Gardeners might also start checking their Indian hawthorns. This year the entomosporium fungus has been filling the leaves with dark spots and causing the leaves to yellow and drop. Some plants are almost bare. This plant was to be fool proof too. Many thought it would take heavy shade and drought conditions. Well, wrong - it needs at least filtered sun and good care like any other shrub.
What do all these plants have in common? Their problems are controllable but you have to apply the treatments. Systemic insecticides applied to the soil and available at local garden centers can control the cycad scale on sagos. And fungicides can help with rust and leaf spot problems.
A number one Gotta Do is check your landscape for these plants and then apply the proper treatment. It's up to you to help these durable plants survive.