Q: We really enjoyed your article about fruit trees. We have a 23-year-old mango tree which is about 15 feet tall and 15 feet wide, it definitely bears more fruit every other year. We have never trimmed it. We are wondering if we should have it trimmed and when is a good time to do it? We usually start seeing mangoes in July and they are edible by the end of August. Can you recommend anyone to trim this tree? We are in Irvine.
A: Since your tree has never been trimmed, you definitely want to hire a professional arborist for this job. The International Society of Arboriculture (www.isa-arbor.com) is an excellent resource for finding a qualified arborist. Please don’t hire some random dude from the parking lot of your local big box home improvement store.
Warning! Mango trees produce urushiol, a substance that can cause severe contact dermatitis. If you have a smaller mango tree that needs only minor pruning and would like to do it yourself, wear long pants, long sleeves and gloves before tackling this job.
The best time to prune is immediately after fruit harvest and no later than mid-December.
First, remove any branches that are dead, crossing/rubbing together, or touching the ground. Fruit is produced on horizontal branches—vertical branches are unproductive and should be removed. Ideally, the tree should have three or four sturdy main trunks with a spreading, open structure. Prune to allow light to reach the interior of the tree, since this encourages fruit production.
Q: When you blast mealy bugs with water, what’s to keep them from climbing back onto the same bush? How do they get on bushes in the first place?
A: Aphids and mealybugs feed by inserting a stylet through plant tissue and directly into the vascular system. The stylet is part of the insect—kind of like a straw sticking out of its face. Once the stylet is in place, it doesn’t come out. The aphid (or mealybug) can just sit there and drink all day without having to move at all. Imagine having your refrigerator right next to your couch. That’s the kind of life these insects are living.
(I don’t want to sound judgmental, but if you currently have your refrigerator next to your couch, you may want to re-think your lifestyle choices.)
When you blast these critters off their roosts, their face parts are left behind. This is highly demotivating and eventually fatal, so they generally won’t climb back up onto the plant.
The few remaining insects will be quickly devoured by predators such as ladybugs, hover flies, and lacewings if they are unprotected. This is why ant control is so important for aphid control.
Aphids and mealybugs are slow crawlers, so they usually spread by hitchhiking. Whenever you bring a new plant into your garden, inspect it carefully for infestation. Look especially closely at new growth, undersides of leaves, and between leaves.
These insects reproduce very quickly, so a few can turn into a big problem before you know what hit you.
Have questions? Email gardening@scng.com.
Looking for more gardening tips? Here’s how to contact the Master Gardener program in your area.
Los Angeles County
mglosangeleshelpline@ucdavis.edu; 626-586-1988; http://celosangeles.ucanr.edu/UC_Master_Gardener_Program/
Orange County
ucceocmghotline@ucanr.edu; 949-809-9760; http://mgorange.ucanr.edu/
Riverside County
anrmgriverside@ucanr.edu; 951-683-6491 ext. 231; https://ucanr.edu/sites/RiversideMG/
San Bernardino County
mgsanbern@ucanredu; 909-387-2182; http://mgsb.ucanr.edu/
