Wanting to grow a front yard hugelkultur, but we've got giant ailanthus stumps

I am hoping some folks out there can give my little family some advice.

We live on a little less than quarter acre in a city, and are becoming somewhat proficient backyard gardeners with the space we have. When we bought our home 3 years ago the yard was a jungle of sumac, overgrown forsythia, poison ivy, dying evergreen hedges, and bittersweet. We have been gradually cutting back the forsythia hedge, have removed all the sumac and evergreen hedge stuff, and have been enlarging the veggie garden a bit every year.
We are excited to turn our back yard raised beds into something more self-sustaining, and we're thinking "hugels" since we have all this brush and wood now.

We also inherited an ENORMOUS and dangerous (because it was rotting inside and dropping large branches on our neighbors!) cluster of ailanthus in the front. Soon after we moved in, we got the electric co. to cut it down for free. We were left with a cluster of 4 stumps that are each 3-5 feet across. We also cut down a big sumac and some ash branches. We put the wood on Craigslist and people took lots, but we still have a giant woodpile of all 3 kinds of wood, and the giant ailanthus stumps in the middle of the front yard.

The ailanthus stumps had some fungi growing on them last year, and the grass has crept back up. We grew some morning glories around/over them and have just let them sit, pulling out any new shoots. I know this wood is not good for plants, but can I try making a small hugel over the stump with brush and other kinds of wood? We are into the idea of edibles in the front yard for all to see and share, but these stumps are in the way! Could we try transplanting some of our trawberries, perennial herbs, etc? Or is this area of the yard a lost cause until we can get the stumps out? I guess what I'm trying to ask is... how allelopathic is alianthus, really? Can it be amended and worked with at all? Can I plant an apple tree 6 feet away from the stump, or will the roots underground have an effect on the soil this far away?

Along these lines, what can I do with all these alianthus logs, besides toast marshmallows in the fire pit? Can I mix a few into my other hugel beds, or should I avoid them entirely?

Looking forward to advice!

Personally, I would build the hugelkultur right on top of those stumps.

Does it make sense to pull the bark off of the wood and stumps before burying them? I read that most of the toxins are in the roots and bark.

I suspect that once you've got fungi growing on the plants nature is already breaking down the natural toxins. Mushrooms are the first line of clean up for all sorts of toxins. Check the fungi forum for topics about bioremediation.
Also, I remember from my mom researching cedar chippings for her vegetable garden (another aleopathic wood) that after about a year there was no more discernible harm to other plants. I wouldn't remove anything from the stumps, just bury them with wood an other organic materials and then plant.

Thanks! Yet another example of letting nature do the heavy lifting, and not over-analyzing things/making them harder than they need to be. I am slowly retraining my brain to think this way.

I think something like this blueberry bed will go on the stump hugel:

http://www.backyardabundance.org/Portals/0/p/Handout-PolyculturePlantingGuide.pdf

Blueberries, clover, yarrow, and lots of strawberries I can transplant from shoots from my bed in the backyard. Maybe with some mint as well. I have not seen other houses in our neighborhood with edibles out front, though next door we have amazing Philippino neighbors who are genius gardeners and grow a jungle of squashes and bitter melon on trellises in their back yard.

I'm fairly sure berry plants are one of the gateway plants for edible landscaping. Also easy to stick in a traditional looking landscape are a lot of herbs and fruiting trees.

If you're willing to put up a trellis, a lot of bean vines are beautiful. I did Thai red noodle beans last year, lush heart shaped green leaves, purple flowers and then long purple beans. You might have a good climate for scarlet runner beans which are prettier than most flower vines I've seen.

And if you've got a long enough season, sweet potato makes a beautiful groundcover during warm weather. Very easy and cheap to start from a single grocery store sweet potato, though you might want to order from a vendor who can give you a date to maturity that works for your climate. Texas has a much longer season for these than you.

If you can't tell, edible landscaping is where I get excited. It's a lot harder for me to 'forget' to water the garden if I know I have witnesses so my edible landscape in the front yard tends to do a lot better than my more traditional vegetable beds in the back.

Casie- thanks for the encouragement! Good point about keeping up appearances... We have some of those 60s curly metal poles from the base to the roof of the front porch. Ugly but great for training things to grow on. We have some native honeysuckle growing up some of them. I love them and the bees do too. But now I am thinking maybe peas or beans can grow up the others, instead of morning glories like in past years.

I don't think we are ready to do away with the grass entirely, just because we have a little one at home and our time is limited, but by adding the berry hugel in front and possibly planting an apple tree too, we are decreasing the lawn size bit by bit. Do you have any experience with seeding other groundcover plants into existing grass, such as clover, violets, or creeping thyme? I was thinking we might try that in the area that still has grass.

Not exactly ground covers, but I've had good luck intermixing wild flowers with my grass. I walked through in the fall (though there are some you can do in spring) and looked for anywhere I could see the dirt beneath the grass and sprinkled the seeds (big jar with a shaker style top) then walked over them. The hard part has been managing the grass without killing the flowers, but there are many short growing flowers if that's a route you want to take. There's a post in the Lawn forum where a guy is looking to grow "the world's weediest lawn" which is full of discussion about edible plants for lawn areas. https://permies.com/t/50142/lawn/world-weediest-lawn

My cilantro that I let go to seed in the garden last year has also managed to successfully self seed itself into the lawn this year. Here it's a cool season annual and so has less competition from the grass than most would.

There's a thread here that covers different ways of dealing with stumps. Adding nitrogen in the form of manure or pee (or coffee grounds, or whatever) seems like a good fit if you want to plant into the stumps, since they are presumably mostly carbon.

Thanks and yes! The other stump post had some good tips. We have had a few warm weekends so far, and today I finished covering the giant stumps over with leaves, compost, sticks, a bunch of upside down grass/turf, and some soil. I tried to hack at them a bit with an axe. They had lots of white mushrooms in them before I covered them up, which I took as a very good sign!

I think I am going to put off planting blueberries there for a year, and will start with the rest of the guild (yarrow, spearmint, strawberries, something nitrogen fixing like lupine or clover), giving the thing a year to "cook". Then I can add the blueberries in the fall or possibly next spring. They are big suckers, these stumps, and I did not have as much soil to cover them as I would have liked.