What harm are the aphids causing? What exactly is she objecting to?

OK. Thank you.

"Someone suggested spraying with water, but she was concerned it was too tall to get a strong enough stream that high."

If the water can reach that high, it will be strong enough for aphids.

tj

OK, she got back to me after I told her your responses. Apparently, they create a black dust type material that covers her yard and makes it unusable.

tsugajunkie- I offered her the use of my power washer.

That is likely sooty mold growing on the honeydew secreted by the aphids. Yes, it's annoying. If it were me I would get rid of the bay tree, but as you say...

Not sure you need a power washer. As I said, if the hose can spray that high, it is all you need. For example, a hand held sprayer you squirt by hand is plenty strong for aphids.

tj

That's some infestation if the sooty mood is producing a nuisance all over the yard. Normally it just stays on the tree where the honeydew is. Maybe it's different in a hotter drier climate.

btw just out of curiosity can I ask what genus this bay tree is? Laurus or Umbellularia?

Floral I grew up in central NJ, where Liriodendron was native and ubiquitous. We had 4-5 of them shading the driveway/parking area and in the spring when the aphids were active the honeydew dripped onto the cars and then got covered with sooty mold. My parents eventually decided to have the trees sprayed each spring, doubtful that that is something that one would consider today.

The same thing happens under lindens here, Sara. It was the reference 'blackdust' that 'covers her yard and makes it unusable' that seemed odd to me.

Sooty mold does not make a dust and it cannot just blow or drift around a garden!! It only grows on substances that are coated with the insect honeydew and sticks to them very securely! In fact, it's darn hard to remove from any surfaces it does develop on and requires some serious manual effort to remove.....even when fully dry!!

floral, as I said, I don't even know this woman, let alone the kind of tree she has. Just asking to help her out from a ? on NEXTDOOR. GG....relax!

OK, closing this conversation! I just asked for a neighbor who posted on NEXTDOOR. I don't want people to get into arguments about this!

Nancyjane, please don't mistake our discussion for an argument. It's just a fairly typical chat between very keen plant people curious to know what's going on with this tree.

Asking the genus was simply my attempt to understand the problem better. Where I live a bay tree is always Laurus nobilis. But I am aware that there are other species given that name. Knowing the species in question could be very helpful in diagnosing and easing the problem. Plus I just wanted to know.

And I was only pointing out that any "black dust covering the yard and making it unusable" was not coming from the sooty mold. Sooty mold is not a dusty substance and it does not migrate or float around a garden covering everything but stays firmly affixed to what it is growing on. If this is not an exaggeration, then the dust is coming from something else.