I put walnut leaves on my garden beds for 2-4 weeks, do I have to take off the first layer of soil?

Hi there,
we made the great mistake of mulching with unknown leaves and then discovered they were walnut. They have been on one bed for around 4-6 weeks, on the other for maybe 2 weeks. AI has informed me that it would be best to get some of the topsoil off to make sure no juglone that might have leached is left. What is your human advice on this? This was such a mistake, I am so sad
Thank you in advance!

Google tells me juglone breaks down quickly in soil (slower in actual wood), so should be clear again in a month or so. And your levels are likely to be very low anyway from a temporary application of leaves as a mulch. I'd just leave it until spring for planting. Maybe mulch with some other material, which will promote more biological activity in the soil and speed the breakdown.

At my last house, two of our big trees were black walnuts and we mulched with all the leaves that fell. Never had a problem that I'd trace back to that.

Google also tells you juglone tolerant plants.   If you look it is mostly what you want to grow so it may just suppress the weeds so is beneficial.

I think it will be fine, having built hugels under the drip line of a walnut and having all but the most sensitive plants (tomatoes) seem ok. It was a very old walnut that rarely produced many nuts, the husks of which seem to be the most concentrated with juglone, along with root exudates. It would be a good experiment to plant it with half juglone tolerant plants, and the other half intolerant plants, then observe and share the results. Gaia’s garden is a good resource for juglone sensitivity and much more. Thank yoi for getting this experiment started for us all!

black walnut's allelopathy is a myth.
https://pubs.extension.wsu.edu/do-black-walnut-trees-have-allelopathic-effects-on-other-plants-home-garden-series

As I have learned, the chemical in walnut leaves is called juglone, which can harm some plants, but not all.  
I would simply remove the top layer of walnut leaves, and mix in a good layer of compost.

Shahar Goldin wrote:black walnut's allelopathy is a myth.

That was an interesting read, for sure, and I'm sympathetic to that stance because it supports my own observations. But I think "myth" is a little too strong. The paper cites a bunch of reasons not to believe but also says that the research needed to really know just hasn't been done.

In fact, I'm going to pin that PDF here in case it ever vanishes from the WSU webpage.

Shahar Goldin wrote:black walnut's allelopathy is a myth.
https://pubs.extension.wsu.edu/do-black-walnut-trees-have-allelopathic-effects-on-other-plants-home-garden-series

...OK... could someone save me fifteen minutes of downloading that paper, and just tell me: is it a myth?
I planted two walnut saplings at my summer cottage in central Finland last year, betting on climate change to get us warmth soon. But if they poison everything underneath them, that's nsg.  

I'm not an expert by any means, but here my personal take. I have a giant English walnut. Nothing ever grew under it. A couple years ago we had some huge limbs break. We pruned it severely. We now have some weeds growing under the tree. I think sometimes things like this are observed and they run with it. I'm team on the fence. Like sunflower, and a bunch of other plants they have an ability to protect there space. It really depends on what you want to grow, and how close do you want it.
I built 1/2 of a  hugelkultur with English walnut wood. Both halves produced the same.
I grow veggies, fruit, herbs, and flowers. No way to keep walnut leaves out in the fall. I don't notice a difference between where there are, or were lots of walnut leaves or not.
Not only do I deal with walnut leaves, but I grow English walnut trees by the dozens, thanks to our squirrel friends. As soon as I realize what it is pull it out. But they grow right next to all the plants I want to grow, and I have never noticed any harm.
On the other side, I have an old English walnut, and the English part died. It's not a black walnut. I have tried to plant 2 bare root trees about 10 feet from this tree. Both didn't make it. I thought I did something wrong, but maybe it's the tree?
So I think like almost all garden questions the answer is it depends.
Good luck