Reddish brown roots are most likely the redwood. Liquid Amber roots are gray like their trunks and are often surface dwellers. Yup, tree roots grow ANYWHERE they can find resources. The richer and wetter the soil, the more they proliferate. If the soil in the raised beds was more like the standard stuff in your yard, the new roses would probably have as great a chance of success as the rose against your fence, closer to the redwood. I commiserate with you. I have to rip out white birch roots from an above ground planting two to three times a year. There are no drainage holes in the plastic liner used on top of the soil and held in place with large boulders and river rocks, yet the blamed roots figure out ways to grow up the insides of the rocks and over the lip of the liners, as well as punch holes in the liner bottom. There is no way to prevent tree roots from entering anything containing soil and water if there is any soil to container contact. It requires solid stone or solid concrete between them and the container, or they WILL find a way in. Good luck! Kim

We find the neighbors Fir tree roots all over. I use a reciprocating saw and tree blade to discourage the roots from invading into beds here

My sympathies are with you. My whole front yard inside the fence is invaded with Monterey Cypress roots. After much trial and error which included wine barrels (I put the barrels on the ground and the bottoms rotted and the tree roots filled up the barrels) I am now resorting to 25 gallon pots raised on concrete blocks and planted with roses. I hope you can find a way.

Diane

I would hire a backhoe crew to dig a trench around the drip line of that tree. Make it about 4-5 feet deep. Get some pond liner material and make one continuous strip. Place it in the trench making sure the top and bottom curves toward the tree. Fill the trench back up. You should see the top edge of the liner just laying on top of the ground. You can cover that with mulch or trim. Any roots headed outward will hit the liner and be directed back towards the tree. Should last for 20 or more years if you get good pond liner material.

If that tree puts up suckers from the cut off roots then all bets are off so check on that before digging the trench.

BTW they use this method to control bamboo. Maybe a search on bamboo control will give you a better method.

Toolbelt

Interesting idea, perhaps, but not in California, particularly where there is any wind, rain or compacted soil. Damaging that level of root system is a sure fire way to induce Oak Root Fungus as well as losing the tree to wind. The drought here has already stressed trees (and everything else) terribly, Eliminating portions of their root systems is going to set them back tremendously, causing even more damage. IF we get the El Nino this winter, you can be completely sure whatever rains we receive will be followed by winds. Reducing the anchoring ability of the roots is highly likely to result in the tree falling over. All those damaged, severed roots remaining in the soil are prime fodder for Armillaria. There hasn't been any root disturbance here, yet the oak next door; several of their huge xylosma; several of my dodonea; my old, large Mutabilis; a few of my large hibiscus, have all either died, died back or otherwise suffered damage from the fungus. I lost the established, main part of the Mutabilis. Only a tip rooted piece further along the fence line remains...and that only until the mycelium reaches it. This soil isn't compacted nor is it water logged. They water significantly more than I do as they attempt to maintain lush plantings, while I do not.

No, I would not attack the roots of the redwood. There is far too much to lose, especially in such a severe, weird year. Kim

Thank you so much, everyone! I really appreciate your helpful and informative responses and it confirms what I suspect - that it's the redwood trees. Argh!

Since I think I'll just leave the trees alone and can't plant veggies or roses now in those beds, maybe I'll just fill them with raspberry bushes. They seem tough and vigorous enough to compete with the tree roots...hopefully!

Thanks again and have a happy weekend! :)