Bearded irises are relatively easy to grow and maintain, but like many garden flowers, some natural problems as well as bacterial and fungal problems can present themselves at any time. Being able to recognize these quickly is important as some can be the demise of your bearded iris in a very short amount of time. This is not an all-inclusive list, but these are the popular problems that you may notice in your flowers.
If you notice that your bearded irises are not flowering properly or the flowers themselves are droopy and weak, there are a few natural problems to look into that are not disease-related. It is best to issue these first before moving on to pathologies. Irises do not do well if they are in shade most of the day. If this is the problem, they will not get better until they are moved. They also don't do well with too much nitrogen in the fertilizer. Look at what you used last and note to use something with less next time you fertilize. Also, if you are plating your irises too close together, this can cause problems because there are not enough nutrients in the soil for all of the plants. Divide them up and plant them further apart or in a different garden.
Unpleasant Odor Near Rhizome
This is never a good sign in plants and usually mean that some type of rot is occurring. Bacterial Soft Rot is a serious diseases of irises and is comes in through damaged parts of the rhizome. This will make the rhizome, as the disease name says, very soft and mushy. The smell will be coming from this area. If the damage is not extensive, cut off infected parts of rhizome and plant. If it has infected most of the plant, get of it immediately and don't let it touch any of the others.
Small "Seeds" Around Droopy Leaves
If you notice small, red-brown seed-looking circles around where drooping leaves are meeting the rhizome, your plant has acquired Crown Rot. This is a fungus, and the small circles you see are spores. Carefully remove infected leaves and avoid touching any other plants with them. Trim other leaves so infected areas can get more sun and air circulation which will kill the fungus. Within a few weeks, the flower should be looking stronger and healthier.
Bacterial Leaf Spot presents itself in small, brown spots on leaves. Fungal Rust is an orange-gold color and a bit dusty in appearance. Remove infected leaves before winter or you will notice that the disease will spread rapidly once the days start getting warmer and more humid. Consider spraying with a fungicide. If leaves are mottled in appearance, your iris has contracted Mosaic virus. This is a virus transmitted by aphids (small bugs that can take over your plant) and the only way to get rid of the virus is to remove diseased plants. It is important to not touch them to other plants as, if there is an injury on a plant and it is touched, it will likely develop the virus.