Potted bay laurel (laurus nobilis) turning brown, why?

[Horseflesh]

My potted bay tree had a run-in with scale insects, which I was able to address with the forum's help.

Unfortunately, with the bugs defeated, my poor tree is now turning brown, and I don't know why. Since I am new to gardening it's probably something basic.

The tree has been inside for about 5 weeks, since I read they are only cold-tolerant down to 25F. It hasn't quite gotten that cold here yet but it does happen every year. I would hate to miss a forecast and kill my tree thanks to one cold night, so I thought bringing it in was best.

Therefore, it's only been under indoor lighting for ~5 weeks. When I noticed it turning brown ~2 weeks ago I put it in the garage, under shop lights which are much brighter than the lights inside the house... Though nowhere near even winter sunlight.

I have been watering it infrequently but for the last 2 weeks have tried to keep soil moisture in the mid-30, whereas prior to that it was in the 20-30% range.

So, am I killing it with too little light? Too much water? Too little water?

The whole plant looks like this sample of leaves. It's in bad shape.

Thanks if you can help!

 

[Oliver Buckle]

It is usually moisture, they like it fairly damp. In a pot a good high nitrogen feed can help, those leaves are not as dark green as they can be. I don't know about America, but 25F seems very cold and I wouldn't expect it to last, I would be tempted to keep it outside and give it some protection, natural light is nearly always superior.
While the above ground growth might well benefit from protection it is the roots of potted plants that really need it, a good wrap around the pot to stop it getting frozen through. Temperatures are usually colder at ground level, so pots are vulnerable, but often the plant in them is lifted out of the really cold zone. I use bubble wrap on the pots and hang on to the largest clear plastic bags, cut off the base to make a tube, then slip them over my potted plants, leaving the top open to breath and get light.

 

[Horseflesh]

I'll try putting it back outside. We're having a mild winter so far, hopefully that will persist.

The moisture meter says 33% right now, but if I inspect the soil it doesn't feel damp at all. The soil is much darker than the very top later that has completely dried out so it has obviously soaked up some water... But if I stick my fingers in there, I can brush all the dust off easily. Maybe that is too dry.

Thanks for the help, I really hope I can save this little tree.

 

[cpp gardener]

Probably too dry. If it’s outside you can water it more often, especially if it’s in a sunny location. Several times a week is okay.

 

[Oliver Buckle]

That sounds too dry. On the one hand it is easy to overwater things in winter when plants are not using as much and there is less evaporation, on the other it is evergreen, so still using some, and likes it damp.

 

[Horseflesh]

Thanks everyone! I will water more, take it outside, and report back!

 

[lifegardener]

Thanks everyone! I will water more, take it outside, and report back!

Good drainage is also important.

 

[Horseflesh]

The pot seems to have good drainage and I will take care not to let it sit in a puddle.

 

[lifegardener]

The pot seems to have good drainage and I will take care not to let it sit in a puddle.

Send us a photo when it begins to "perk up"

 

[Horseflesh]

Here's an update on my lightly abused bay laurel.

Thanks to the advice here, I had put it back outside as long as it wasn't too cold, bringing it inside if it was going to get into the 30s. I also started to water it a lot more. That seems to have stopped leaves from turning brown.

Now that the weather is better, the plant is perking up for sure. I see a lot of new growth, but I still have concerns.

I still have a lot of leaves that are half-dead or worse. Should I remove them?

And, a lot of the new growth has these spots. What is this? I thought it might be dirt but it won't rub off. It reminds me of pics I have seen of plant viruses.

Lastly I still see some scale insects, but a combo of horticultural oil and pesticide derived from neem oil seems to be controlling them.

Thanks for the help!

 

[Tetters]

I think that's the start of shothole fungus.

 

[Horseflesh]

Thanks, I will look that up and keep an eye on the tree to see what develops.

 

[cpp gardener]

I think they're from the spray. A little phytotoxicity but not seriously damaging.

 

[Horseflesh]

Fingers crossed. Thanks folks!