Spring is the season when plants start growing again after being dormant for the winter. It is also the time of year when many disease organisms come out of dormancy to begin infecting plants. The source for many disease spores is in the dead organic matter left behind from the same infection last year. When diseased plants die, it is best to clean up all the dead plant parts, so they can't be the source of a new infection.

Today, we have two common problems on two common plants, but they are just good examples of many other groundcover and perennial plants that have disease problems. The first step in curing plant diseases is to look at your plants often enough to notice the first signs and symptoms of sickness. The sooner you see a problem developing the sooner you can remove the sick plant parts to stop the spread or the sooner you can start other treatments.

Question: We have a ground cover bed of vinca that is having problems. The plants are turning brown and then black. We have been keeping the bed watered, but that is not helping. What can we do?

Answer: Vinca minor is a very nice ground cover plant that spreads without being invasive most of the time and it has pretty blue flowers in the spring.

As you have noticed, the new growth starts to wilt and then the leaves turn brown. After a few days the stems turn black and the whole plant may die or just a few stems. The disease spores are moved by splashing water from rain or irrigation.

If it does not rain for a while, try letting the bed dry out by turning off the irrigation for a while. Do not water at night or in the evening if the leaves cannot dry off before nightfall. Prune out any dead or dying branches, as that is where the spores are coming from. Remove any plants that are more than half dead; they will mostly continue to die anyway. If you use a pruning tool or shovel, clean them with rubbing alcohol or bleach before moving on to the next plant and after you are done.

Use a fungicide that says it treats Phomopsis or Phoma and follow the label directions. Unfortunately, it will probably require the fungicide to be applied in a drench, which means you must thoroughly soak the whole bed again.

Another fungal disease that attacks vinca is also related to the problem of over watering. This fungus attacks the roots first. The first visible symptom is when the stems and leaves look wilted. They do not get the black stems and crown as in the other two diseases. The first impression is that the plant needs to be watered, but that only harms the plant more. If the flowerbed needs better drainage, or there has been consistent over watering or rainfall, then the plants can easily catch this disease. Follow the recommendations for other diseases and look into creating better drainage for the flowerbed, since prevention is better than trying to cure the disease.

Question: The flower buds on my peony plants turned gray and moldy. What do I need to do to prevent this from happening?

Answer: This is also a fungus disease, but instead of being hidden inside the plant, it is growing on the outside. It is called gray mold for obvious reasons. The fuzzy stuff that you see is the millions of spores getting ready to spread to more plants. Cut off any diseased plant tissue. In the fall, also remove all old peony plant parts after they die. This fungus grows in cool wet weather in spring and fall. You only notice it in the spring, because that is when you are looking for the flowers.

In the spring, spray the emerging shoots as they come out of the ground and continue spraying them until after the flowers are done blooming. If they are already half grown before you begin spraying, go ahead and spray, but you might not get full control this year.

Use a fungicide that says it will treat Botrytis diseases. If you can get a fungicide that also says it will treat Phytophthora diseases too. Phytophthora is a deadly disease in peonies. It kills the whole plant quickly. It turns the whole thing into a brown dead mass with black lesions on the stems and the roots are wiped out too. This is a soil fungus, so you will need to treat the soil and remove all of the dead plant.

Email questions to Jeff Rugg at [email protected]. To find out more about Jeff Rugg and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.