Question:
Several years ago, we installed a hot tub adjacent to a Crape Myrtle. Since then the leaves on the Crape Myrtles has develop a powdery white film during the summer months. This year, it’s worse than ever. I'm wondering if the heat from the hot tub is the culprit?
Answer:
You’re correct in suspecting the hot tub as the problem but it’s not the heat that’s the issue. Instead, it's the moisture escaping from the tub when it's in use. The moisture settles on the leaves setting up the perfect conditions for the fungal disease, Powdery Mildew, aka the white film. This is the same problem seen on apples, roses, dahlias, zinnias along with many other ornamental plants. Powdery Mildew is a summer disease where there is a constant afternoon marine influence while it rarely shows up were it’s warm and dry. Mildew spores are airborne and abundant. They only need the right conditions such as mild nighttime temperatures and moisture to be a problem. Mother Nature provides the temperature and the hot tub is providing the moist air. The foliage on the Crape Myrtle along with any of the other host plants needs to remain dry after the sun goes down; otherwise, the Mildew thrives. Your problem perpetuates itself because the hot tub usage is typically in the evening hours. There are many different types of fungicides available to control Powdery Mildew. Unfortunately, none of them eradicate the problem: hence, they have to be reapply frequently. The size of the tree eliminates any of the systemic controls so you’ll have to apply a foliar solution. Your best bet is Horticultural or Neem Oil to suffocate the spores and it’s reapplied every two to three weeks during the summer and fall. The other option is to do nothing and live with the white film. While Powdery Mildew looks bad, it doesn't kill the tree.
Question:
We have a beautiful Mission Fig tree started from a rooted cutting but the figs form and dry up. My grandson did so research and believes that we have a male tree to our dismay. Will planting a female tree solve the problem?
Answer:
First off, this is not a male tree as figs form so it has to be a female or one that has both reproductive structures in the flower. Fig pollination is a bit complicated because it is accomplished in several ways. Some varieties uses an insect called a gall wasp while others varieties don’t require anything. This is a very simplified answer. Mission Fig does not require a second tree for pollination. It uses a gall wasp so the fruiting problem is due to something else. So I'm thinking that irregular watering may be the cause of the problem. I'd have a watering basin around the tree that's six inches tall and extends from the trunk to the beyond the drip line and I would be watering weekly, once the rainy season concludes.
