What trees are okay around septic mound?

[TabeaK]

Hello hive mind, I have gone down the rabbit hole the last few days trying to pick out trees to replace all of the Ash trees we lost to the EAB and I am getting more confused, the more I research, lol.

Basic Facts:
- Central NJ location, Zone 6
- Mostly clay soil, fairly wet
- We have a septic tank/septic mound system in the front yard (replaced in 2019), it is an aerobic system with a pump & aerator & a bunch of other stuff I don't fully understand, but it has been working beautifully and passed its latest annual inspection
- We had gorgeous mature ash trees providing shade to the house - all gone as of this spring and cut down because they died from EAB
- We have numerous maples thriving in the environment, including what is mostly a maple forest (with a good number of dead ash trees mixed in) behind the house

I want to replace those ash trees (height was between 40 - 60ft) that used to provide shade to the house - obviously ash is out, we have no viable ash trees left in our area and the EAB is very active. I would like deciduous trees..

For shade/privacy reasons I want to plant in the general vicinity of where those ash trees used to be. Which is between 45-50ft each from the far end of the septic mound leach lines (measured from the end outlet pipe caps that we have in the septic mound) AND the actual septic tank (which is under a garden bed that has been planted with shallow rooted perennials). The pipes connecting the septic tank to the beginning of the mound leach lines are more like 70 - 100ft away. We'd also be 30-40ft+ from the house foundations.

I originally dreamed about some gorgeous weeping willows that would help with wet soil - but then learned about invasive roots that need to be 100ft + from septic components. So that is out... Next idea was tulip poplars for their fast growing behavior. But those also have the invasive root problem. As, apparently do most maples, beeches, birches... I have also seen ash on that list, but obviously, there were ash trees there before for many, many years before I ever moved there.

So what does that leave me with tree-wise - oaks? I need something that will reach at least 30-40ft as it is for shade provision...

Am I overthinking this and 40ft+ or so distance is actually fine?

 

[pdqdl]

sycamore trees love lots of water, and are often found in creek beds with standing water. Clay soil isn't apparently a problem for them, either, since I live in Clay County, Mo, and they are common as dirt up here.

Another option might be Bald Cypress. This is a tree that will take almost any amount of water, but their visual appeal is considerably different than Sycamore trees.

There are many plants that will do a good job for you, just do a bit of research and pick what you like best.
One of the best guides that I have found is this one:
https://www.missouribotanicalgarden.org/plantfinder/plantfindersearch.aspx
Use the advanced search feature, and dial in to what you like best. Do consider, however, that New Jersey has a different climate than Missouri.

 

[TabeaK]

Thank you! We have lots of mature Sycamores in the area, but I am not sure water-loving is a feature I can get away with ~50ft from my septic leach mount...

I'll have to look in Cypress.

So far the only other options on the list are Oak (Red, White, Pin or Willow) and black gum.

 

[pdqdl]

When I was growing up, we had a willow tree growing up in the middle of our 2 acre pond. It was in water 5 feet deep.

Sycamore won't care about your septic leach, whether 5 feet away, or 500. It will even thrive with all the extra fertility. Now I'm not so sure what your septic leach will have to say about all the invasive roots planned from introducing a tree. I've seen too many tree roots deeply penetrated into areas that were supposedly root proof.

I even dug up a French drain that I installed because it quit working. Tree roots climbed down a 10' rock wall, grew through the gravel talus area, through 8' of clay/mud, and completely plugged up the 4" drain tile that was protected by two layers of filter fabric.

Now I'm not an expert on septic systems, but I'd probably recommend keeping all trees out of the area. So far as I am aware, there are no trees of any variety that will not reach out a long, long ways to find your fertile effluent.

There is a cave tour in southern Missouri that loves to show the visitors the tree roots coming into the ceiling from the ground level, 150' feet up through mostly solid rock.

 

[TabeaK]

Yes, we are not planning to plant any trees or shrubs either on the septic mount or anywhere near the actual tanks and waste line, in fact those areas are already landscaped with either grass or perennials.

I am looking to replace trees that are 50ft away from the septic mount (which has the leach lines embedded in it). There used to be large mature ash trees in those exact spot, but thanks to the EAB they are gone, as are at least 20% of the trees in our wooded property.

Neither Willow nor Sycamore seem to fit the bill as I suspect their roots would make it across those 50ft eventually.

Not planting any trees is not an option - it leaves us with a gigantic open expanse of just grass - which doesn't help shading the house and isn't particular ecological either...

 

[pdqdl]

A tiny weeping cherry will have tree roots reach out more than 50 feet ...Eventually.

I don't know of any tree that is rated at having short roots. If you are really, really concerned about protecting your leach field, do an excavation around the pipes and install a serious root barrier. That'll slow the roots down a lot, then plant whatever you want.

Another option might be to just run a trencher through the perimeter path every 5 years, and keep cutting off the problem roots before they can infiltrate your system.

 

[JRM]

If you want something that you can enjoy in your lifetime oak or maple may not be the best option. They are excellent choices as shade trees just not something that will grow particularly fast. Red maple and red oak are one of the faster growers, around 30 years each.
I have a sugar maple and a tulip (poplar)
growing ~40-50 ft apart, planted at the same time less than 20 years ago. The tulip is easily twice the size of the maple and is an excellent shade tree being on the south west corner of the house. Maple doesn't have enough canopy yet to be of much use. But the maple will outlast the poplar 9 times out of 10. Tulip is more susceptible to disease and rot, ice damage, etc. Tulip sheds alot of twigs and branches and is a PIA to clean up. They all have their trade offs.

 

[pdqdl]

Fast screening?

Lombardy poplar. You'll have a brilliant 40' screen in just a few years. Nice fall color, and not too many leaves, either. Furthermore, they are unlikely to ever plug up your septic lines, as they start dying off after 20 years. Cut down, rinse, repeat.

 

[TabeaK]

Hmm interesting, had not come across the Lombardy Poplar before - probably because I was only looking at Natives.

@JRM, yes the tulip poplar was my original choice, until I read about the roots and measured the distance to septic mound. 50ft are probably not enough for those...

 

[pdqdl]

Just remember that all fast growing trees come with all the fast growing tree problems.

https://www.thespruce.com/lombardy-poplar-trees-2132395

 

[pdqdl]

Because those trees are so short lived, if you like the vertical "fastigiate" appearance, you might consider planting a slower growing tree in alternating locations. Other candidates with a similar appearance:

• ‘Red Obelisk’ European beech
• Goldspire™ ginkgo
• ‘Sunspire’ magnolia
• Kindred Spirit® oak
• Hornbeam (s l o w-g r o w t h) Great tree otherwise. Many varieties available if you look hard enough.

 

[TabeaK]

Thank you @pdqdl. I do prefer more round canopies, but I will live with whatever I can make work with the restrictions I have.

These are some great suggestions I hadn't considered or come across those. Gingko species and Hornbeam look interesting, even if the former is definitely not native.

 

[pdqdl]

Be advised that female Gingko trees drop fruit that is positively vile smelling. The folks from Asia are fond of harvesting the nuts and eating them, but I tried it. Horrible mess, and they just didn't appeal to me. Otherwise, they are almost a problem free tree.

Hornbeam is a favorite of mine. Not many in town, their foliage is extremely dense. I've only touched a very few with any kind of pruning equipment, as they are very slow growing and very low maintenance.

 

[TabeaK]

Yep, I read that - apparently smells like vomit, lol. If we go with that will make sure we buy male trees...

Also just realized Hornbeam is called Ironwood around my way...so native, bonus!

 

[pdqdl]

The scent in the fruit is fairly common, although quite repugnant: Butyric acid, a four carbon carboxylic acid. It's just a butane molecule with a couple of oxygens added.

 

[dboyd351]

Some trees (like loblolly pines) have primarily tap roots, so they are less prone to send lateral runners into your drainfield. They also grow very fast and can get 80-100 feet tall. Of course they are evergreen, not decidious. I have a drainield that was designed with sevral 80-100 ft loblollies, 20-30 ft eastern red cedars and 10-20 ft hollies spaced throughout it. It has been working fine since 2007.

The lot is primarily forest and they picked an area, cleared most of the trees, but left the ones mentioned and installed the drainfield theough the area, leaving those trees.

I know this is not standard practice but it has worked fine for over 15 years. We only have 3 people living in a 4 bedroom house.

BTW - in my opinion you are far better off without that weeping willow - they look pretty but make a tremendous mess, constantly shedding 'branches' and leaves. We had one in a wetland area were I worked and we cut it down because the mess was so bad and continual.

 

[TabeaK]

Thanks for your comment. Fascinating that someone actually planned a septic field with trees in it!

I certainly won't go there, as our dense clay soil required construction of a mount system in the first place, but very interesting nonetheless! I do live in a wooded area as well, where everyone is on septic, but all new constructions are typically the expensive mount systems in open areas (often have to be cleared from trees) due to tightening regulations...

 

[kenmbz]

For some fill in trees, under the wider canopy we use dogwoods. As long as they get enough shade they work well.
I have a few near the mound, with some mature tulip poplars at about 100' or so away.

 

[dboyd351]

we have mound systems here too but they are reserved for areas where the soil does not percolate because of excessive clay or a very high water table
my property has some clay, but more sand, so it percs well

Good luck with finding suitable trees

I also have a dogwood inmy drainfield area andit is doing fine

 

[capetrees]

Hello hive mind, I have gone down the rabbit hole the last few days trying to pick out trees to replace all of the Ash trees we lost to the EAB and I am getting more confused, the more I research, lol.

Basic Facts:
- Central NJ location, Zone 6
- Mostly clay soil, fairly wet
- We have a septic tank/septic mound system in the front yard (replaced in 2019), it is an aerobic system with a pump & aerator & a bunch of other stuff I don't fully understand, but it has been working beautifully and passed its latest annual inspection
- We had gorgeous mature ash trees providing shade to the house - all gone as of this spring and cut down because they died from EAB
- We have numerous maples thriving in the environment, including what is mostly a maple forest (with a good number of dead ash trees mixed in) behind the house

I want to replace those ash trees (height was between 40 - 60ft) that used to provide shade to the house - obviously ash is out, we have no viable ash trees left in our area and the EAB is very active. I would like deciduous trees..

For shade/privacy reasons I want to plant in the general vicinity of where those ash trees used to be. Which is between 45-50ft each from the far end of the septic mound leach lines (measured from the end outlet pipe caps that we have in the septic mound) AND the actual septic tank (which is under a garden bed that has been planted with shallow rooted perennials). The pipes connecting the septic tank to the beginning of the mound leach lines are more like 70 - 100ft away. We'd also be 30-40ft+ from the house foundations.

I originally dreamed about some gorgeous weeping willows that would help with wet soil - but then learned about invasive roots that need to be 100ft + from septic components. So that is out... Next idea was tulip poplars for their fast growing behavior. But those also have the invasive root problem. As, apparently do most maples, beeches, birches... I have also seen ash on that list, but obviously, there were ash trees there before for many, many years before I ever moved there.

So what does that leave me with tree-wise - oaks? I need something that will reach at least 30-40ft as it is for shade provision...

Am I overthinking this and 40ft+ or so distance is actually fine?

40' distance away from the septic is fine. The roots may go that far, doubt it, but if they do, they're not going to be so dense as to impact your septic.