Since Red Oaks give off much less juglone than Black Walnuts, I decided to try to live with the situation. Last year I used a post hole digger to dig down and sever the small roots in the hole, backfilled the hole with rich soil, then planted in the backfilled holes. IT WORKED! This technique resulted in zero plants lost throughout the season. So this little experiment tells me that it is possible to grow vegetables near the Oak by simply separating the roots from each other.

Fast forward to this year. I would like to switch to raised beds on the part of the garden closest to the red oak. I would like to set the raised beds on landscape fabric to keep the Oak's roots from coming into contact with my vegetables. My raised beds will be 24 inches high, and sit directly on the landscape fabric.

My questions are: Does anyone see a better solution to the problem (besides cutting down my neighbor's 100 foot oak)? Will a 24 inch high raised bed be OK for tomatoes? Will the landscape fabric allow proper draining if the bed just sits on top of it?

Thanks!

But over time that landscape fabric will degrade no matter the quality to begin with. As that happens the tree roots will invade the bed. Indeed some invasion happens even while it is fresh.

They are drawn to the moisture and the easy to permeate soil consistency. How long it will buy you I can't say but it won't be a long term solution. Only moving the bed to another location can accomplish that but you might also consider using hardware cloth instead of the landscape fabric for better drainage and longer lasting effects..

And the depth isn't going to make much difference IMO - 18" is as good as 24". The allelopathic effect**, once in the soil, is in the soil.

That said, living and gardening surrounded by an oak forest (both red and white as well as hickory) as I do I find that growth suppression is more a result of the leaves rather than the roots with these particular species and an annual deep tilling eliminates the majority of the problems caused by the roots. So be sure to eliminate all the leaves from the tree in the garden.

There is also some testing evidence that only certain types of plants - primarily monocots - are affected by the red oak coumarin. So in some part a different plant layout may help.

Just some thoughts to consider.

Dave

For a number of years I managed maple roots (which are fairly shallow) by digging along the perimeter and severing the roots. That worked out OK, and was needed only every second winter.

If you really think it is juglone, try planting come beans, chard and squash. They will be affected a lot less than tomatoes. If you get in a situation where the squash is alive and the tomatoes dead, that would be it. Note the squash plant will be smaller than usual, but alive. I have a large BW close to my house and I have a lot of experience. Tomatoes and potatoes get zapped (solanaceae really) but most other vegetables survive although they do not grow as well.

Thanks for your response. Anyway, I've researched it, and found out that Red Oaks do produce juglone. Also, the juglone-resistant plants have no issues nearer the tree. They thrive. It's just my tomatoes and cucumbers that suffer.

Ken

Sorry glib but the phenolic coumarins from Red Oaks is pretty well established. It supposedly isn't as strong or as fast acting as juglone but still allelopathic, especially the leaves and bark.

Dave

Another thing:
NOT every plant will be affected by juglone. Of all the things that I grew , only tomatoes died. Nothing happened to peppers, okra, cucumber, shiso, bean, gourd ...MAYBE they did not do very well, but they survived.

glib - I think the composting first is bound to make a big difference. Plus the red oaks issue is coumarins (phenyls) rather than juglone and they supposedly dissipate faster, especially with composting.

Dave

It's an interesting chain of events when I plant tomatoes nearer the tree. They start off great. Grow for about a month or more. Then all of a sudden (usually after a hard rain), they wilt and die in about a day.

I scratched my head for years. I planted juglone tolerant plants, and whoa-la! Problem solved. However, I really do need to rotate in plants that are not tolerant.

Thanks again.

My opinion on the Red Oak is that it is seems much less potent than a black walnut. The garden can be managed, by simply keeping the roots away from the vegetable plants.

That's basically my experience. I have no other experience with any other types of oaks. From my research, I'm not sure if I even remember any other oak being an issue.