Yellow leaves on potted laurus nobilis (bay laurel) -- am I overwatering?

[Horseflesh]

I bought a small bay laurel tree in June, and immediately repotted it. It has always had a couple of yellow leaves at the bottom, but has seemed to do OK otherwise. Over the last couple of weeks I have seen more yellow leaves appear, and higher on the tree. Now I am unsure if I am overwatering it, or otherwise torturing the poor thing.

Here are all the details... If you can see something I am doing wrong, please let me know!

• I'm in Zone 8b (near Seattle)
• Overnight temperatures are in the mid-40s currently but cooling rapidly
• The pot is terra cotta
• The pot is under a patio cover so it gets direct light in the morning and indirect light the rest of the day
• Potting soil is G&B Organics Raised Bed & Potting Mix
• Soil moisture is always in the range of 20-40% (3 months of data below)
• When I water, I soak it well, and dump whatever drains into the plastic tray under the pot
• I have not yet used any fertilizer

I realize that a soil moisture measurement may not be accurate, even though I have calibrated my sensor. Maybe when my meter says 20% it's actually 30%... But the readings should be consistent over time.

 

[Horseflesh]

A followup...

I think I have a scale problem. I ordered an insecticide with azadirachtin. I hope I can save my little tree!

 

[YumYum]

Yes those are wierd creatures. You can use neem oil from what @Chuck says.

 

[Horseflesh]

It looks like the active in ingredient in neem oil is azadirachtin, so I went for that directly. The cost seemed similar and this way I know exactly how much active ingredient I am getting.

My poor tree!

 

[cpp gardener]

Don’t panic. Overall your plant looks good, even with the yellow leaves. Since you’re cooling down fast just treat it for the scale and maintain moist but not soggy until Spring. When it starts putting out new growth start feeding it and it will probably outgrow the scale issue.

 

[Horseflesh]

Don’t panic. Overall your plant looks good, even with the yellow leaves. Since you’re cooling down fast just treat it for the scale and maintain moist but not soggy until Spring. When it starts putting out new growth start feeding it and it will probably outgrow the scale issue.

Thank you kindly.

Do you think I need to take it inside for the fall or winter, or only when I think we'll dip below some temp threshold? Soon it will be below freezing regularly at night, but rarely below 25F or so.

It is not a huge pot and I can definitely keep it inside -- though of course inside light won't be as good, even in the best spot in the house.

 

[cpp gardener]

Bring it in when temps get below 25, if that happens. Give it as much direct sun as you can. You can hardly overwater it in that pot outside, unless it sits in water for days.

 

[Chuck]

It looks like the active in ingredient in neem oil is azadirachtin, so I went for that directly. The cost seemed similar and this way I know exactly how much active ingredient I am getting.

My poor tree!

You have hard scale and the poison will not do much against it. Azadirachtin is for soft scale. What the Neem does is smother the scale with the oil it has.

 

[Horseflesh]

You have hard scale and the poison will not do much against it. Azadirachtin is for soft scale. What the Neem does is smother the scale with the oil it has.

Yikes, I have to do more reading I guess, thanks!

Edit to add: I read up on hard vs soft and ordered an appropriate horticultural oil.

 

[Avocado]

I’m not familiar with how reading of soil moisture meter compares to how much I water my potted plants. Looking at the data, it seems there has been more moisture in the soil in October compared to previous months. Since when the leaves started turning yellow?

Without the moisture meter data, I’m guessing too much water is causing the yellowing. I water my potted plant, a small ginkgo, once in two weeks or bit longer, but it’s inside and never outside, because it’s so tiny. (I’m also near Seattle)

 

[cpp gardener]

Your Ginkgo tree, regardless of size, will do MUCH better outside than indoors. They can withstand below 0*F. It will be easier to keep it at the right moisture level outside. You could probably water it every day and not rot it as long as there are drain holes in the pot. Ginkgos naturally turn bright yellow and lose there leaves at this time of year. They also REQUIRE a good chill to grow normally. Put it outside.

 

[Horseflesh]

An update: I seem to have defeated the scale insects and my bay tree has no more yellowing leaves! Now that I know what to look for they will be easy to spot and treat in the future.

Unfortunately now the tree is turning brown so I have to start a new thread!