Q. Most of my trees have bark damage on one side of the trunk. The bark is peeling and falling off of the trees. There are no signs of insects. What could be causing this?
In areas where sunlight exposure is intense, trees can be subject to southwest injury. This will show up on the south- or west-facing side of the trunk. It happens when the cambium expands in response to the sun’s heat and splits the bark open, creating an open wound. This is especially bad in the Midwest, where temperatures can suddenly turn from bitter cold to unseasonably hot.
There are several ways to protect your trees from southwest injury. Painting the exposed trunk with white latex paint diluted 1:1 with water will reflect much of the sun’s heat, though some may find the painted trunks unattractive. Wrapping the trunk can offer some protection, but may mask other problems, such as a shothole borer attack.
Underplanting with hardy shrubs that grow tall enough to shade the vulnerable trunk is my preferred method since it gives me an excuse to plant more flowers and can deter squirrels from climbing into our fruit trees. Geranium, sage, ornamental grasses, rosemary, and verbena are all good candidates.
Q. I planted a bunch of Roma tomatoes because I want to can them and was told that this is the best variety for that. Several years ago, I tried canning tomatoes and ended up with jars that were 2/3 clear liquid and only 1/3 tomatoes floating on top. They tasted okay, but I was wondering if there’s a way to prevent that from happening again.
I gave up canning plain tomatoes for exactly that reason. Recently, I found directions for canning tomatoes that gave me consistently pretty results.
When sliced, tomatoes release an enzyme that causes water to be released, which results in the separation you’ve seen. To prevent this, the tomatoes need to be heated immediately after slicing so the enzyme can be inactivated. (Blanching in boiling water will not do this – the enzyme is only released by slicing the fruit.)
Start by slicing a few tomatoes that have been cored, blanched, and peeled and placing them into a large pot and immediately heat them, taking care not to burn them. As these first tomatoes heat up, mash them a bit to release some of their juices. Continue to core, blanch, peel, and slice, immediately adding each tomato to the pot and stirring so that it heats quickly. This will ensure that the enzyme is inactivated as each fruit is added and quickly heated. Once all of the tomatoes have been added and heated, you can continue with processing according to a tested recipe. For more information, see https://www.healthycanning.com/tomatoes-separating-jars
Los Angeles County
Orange County
ucceocmghotline@ucanr.edu; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; 951-955-0170; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanr.edu; 909-387-2182; http://mgsb.ucanr.edu