CO-Horts Blog

Monday, July 13, 2020

Garden Problem Tour

By Sherie Caffey, Horticulture Agent, CSU Extension-Pueblo County

   This summer, COVID-19 has the Extension office in Pueblo closed down, so I have been working from home. This has given me a chance to look around at things going on in my yard and garden that I haven’t had time to pay attention to in previous years. Of course there is a lot going right, but here is a little tour of the issues I have found this year. Maybe you have some of the same issues, and I can offer some suggestions on what you can do to remedy them.
   I have several trees in my yard that were here when I moved in. While doing some much needed trimming earlier this year, I noticed one of my American Elms had a very black trunk and branches. Upon further inspection, I noticed small brown and white structures in the cracks of the bark that looked similar to mealy bugs. What I have is a pretty bad case of European Elm Scale. The black color on the trunk and branches is black mold and is commonly associated with scale infections. There aren’t many control mechanisms that work well, but if you have Elm Scale you can see your options here: For me, this tree is not in a great place and runs into my power lines so I won’t be sad to lose it and therefore probably won’t treat it. If my neighbors or myself had other American Elms it could spread to this might be more of an issue.
   The next problem I saw in my yard was in my lawn. It looked really great earlier in the year, but with the extremely hot weather we have been seeing in Pueblo I’ve been seeing some brown spots appearing. There are many potential causes of brown spots in lawns, but by far the most common cause is a lack of water due to poor irrigation coverage. I’m sure this is the problem that I am seeing, but to be sure I will be performing a simple at home lawn irrigation audit. To do this, set out identical containers in different spots in your lawn (brown spots and green spots) and run your system. You can measure the amount of water in each container to see if the brown spots are getting less water. To read more about brown spots in lawns click here:,to%20maintain%20a%20healthy%20lawn.
   Next, I checked out my vegetable garden and noticed my zucchini plant had leaves that looked white and powdery. This is a common fungus you might see on cucurbits, called powdery mildew. It’s caused most often by poor air circulation and too much shade. Shade is definitely my problem. Neem and horticultural oils can be used on existing infections, but can damage plants if used improperly so always read the label and check out this link for extra information: I’ve made my first application of Neem oil and am hoping for good results.
   Also in my vegetable garden, I noticed some of the tomatoes were getting cracks and indentions. This can be caused by inconsistent watering. The plants get a bit dry, and then suddenly get a bunch of water, and the fruit basically outgrows its skin and cracks. I think I will try to be better about the watering schedule, and also add some grass clippings or straw as mulch to stabilize the soil moisture. I know a lot of people have various problems with tomatoes. This fact sheet is amazing for narrowing down the problem:
   So that’s a tour through the yard and garden issues I am having. I hope someone will see one of my shortcomings and be helped by it!


  1. “Problem tour“ is a great approach—I should do this myself. Thanks!

  2. Could powdery mildew appear on Peonie (flower) plant as well ashad that issue this spring on my plants. they didn't flower well this spring as we had a late snow and thinkthey were damaged from the snow but again it could be the mildew.

  3. Yes it could infect peonies. Try to create better air circulation and avoid overhead watering. If it persists you can try treating it.

  4. I enjoy garden tours, even if they are tours of 'problems'.