How to remedy jade plant troubles

Q: My jade tree is about 10 years old, and in the last six months the inner leaves have started to turn yellow and fall off. I’m careful about watering. This jade is still in its original container. Do you have any idea what I can do to prevent the leaves from dropping? It’s only the inner leaves that are affected. — Jeff H.

A: When a jade plant, one of the most popular succulents, develops problems such as leaves yellowing and dropping, watering is the most common suspected cause. But you’ve raised the plant for 10 years, and you must be careful about watering, as you indicate, or the plant wouldn’t have lived this long!

Instead of watering problems, I suspect one of two possibilities, maybe both.

You mentioned the plant is in the original container. Jade plants don’t have extensive root systems, and can remain in the same-sized pot for decades, as many jade owners have experienced. And they don’t need frequent repotting.

However, even the highest quality potting mixes can change over time, as salts and natural chemicals from the water change the soil’s makeup and structure. Potting mixes can become hard-packed with less aeration and a greater tendency to become waterlogged. I would definitely repot the plant with fresh soil, even if using the same container, or one slightly larger.

Additionally, I also suspect a spider mite infestation. When I look at the leaves, I see light-colored stippling, or tiny dots, and I’m sensing spider mites.

Spider mites are so tiny they usually go unnoticed on plants until the population explodes, causing symptoms on leaves and eventual webbing. If you flick leaves on a white paper and use a magnifying lens, you can occasionally see the mites.

The oldest, inner leaves where the mites have been working the longest, are usually the first to show symptoms, as with your plant.

To control spider mites, remove all old leaves and plant trash and rinse the plant with a gentle shower of lukewarm water, washing upper and lower leaf surfaces, which will help dislodge at least some of the population. Leaves that are severely yellowed should be removed, as they won’t revert to normal green health.

This would also be the time to repot the plant into fresh soil. Then apply insecticidal soap or neem oil, coating all leaf surfaces above and below, plus the stems and jade trunks

Systemic houseplant insecticide granules, sold at garden centers, can also be applied to the soil, following the treatment with soap or neem oil. Good luck with the jade plant, and please keep us posted.

Q: We appreciate your columns in The Forum. It’s great to see questions being answered, but I also can get confirmation for things I’m doing. As you recently indicated onion plants usually produce larger bulbs than dry sets, I’ve certainly found that plants are the best choice. — Leonard L.

A: Thanks, Leonard, for sharing your onion story. Onions are among the favorite all-time vegetables for gardeners. Growing up in a German household, onions were a main spice Mom used in hotdishes and most foods other than dessert. Onions are relatively easy to grow and can store most of the winter, and our root cellar always had a generous supply.

Leonard continues his onion comments: “I usually get six bunches of onion plants from Dixondale Farms. I was growing Walla Walla in my backyard with only morning and evening sun due to shade trees and the onion bulbs were smaller than expected and of uneven size.

“A Dixondale rep advised me to switch to Candy, which they consider to be an intermediate instead of long day onion. It worked very well, at least for last year’s conditions.”

Dixondale Farms, where Leonard orders his plants, is located in Texas and is the largest grower of onion plants in the United States with a 112-year history of shipping bunches of onion plants for gardeners. Their varieties are divided into long day, generally for the North, short day for Southern winter growing, and intermediate types for the zone in between.

If you have a gardening or lawn care question, email Don Kinzler, NDSU Extension-Cass County, at [email protected] . Questions with broad appeal may be published, so please include your name, city and state for appropriate advice.