need help identifying tree for hugelkultur- Oleander

Hi all,

I registered because i  have dug up a trench and  am ready to  fill it up with  branches of  trees from my backyard.  I got some branches from apple tree and some from my orange tree.  But i could not identify the other tree that has lot of  branches that i want to use in my  hugelkultur bed.  I was ready to do it today, but delayed until i got opinion  from this forum  to see if  this  tree is ok to use  (along with orange)  in my  hugelkultur  bed.  BTW,  i live in  San francisco bay area and the  pictures of the tree i could not identify   is  attached  with this post.   I  have  two  of these  trees  in my backyard  and  i really  would  like to  use  these  to fill up my  6x3  feet  bed  (if  it will not cause problems along with the
orange  tree in the bed ).    Thanks  for your  comments.

The toxic Oleander. But probably fine for hugelkultur.  Just don't eat it!  

Tyler Ludens wrote:The toxic Oleander. But probably fine for hugelkultur.  Just don't eat it!  

If it is  toxic,   will  it leach  toxins  into the  soil  base ?   I was  also not  sure about  orange  tree branch  because i  heard that  any tree that  has  oils  in it  will not  be good in a  hugelkultur base.  Not sure, cause i am new to all this.   I am  also  wondering  if  i can  use the  leaves  of  this   Oleander  tree  in  the  composting  process  i have  going on.   For now, i  have used only  apple tree leaves  in my composting.

I have been re-evaluating my hugel wood choices as I underestimated how determined chunks of cottonwood are about rooting themselves.

I mention this because I have seen this behavior from apple wood used fresh in a hugel. As we did not want apple trees in our hugel it was somewhat annoying, nothing like as bad as the cottonwood would be though.

Getting the wood down and drying out a bit ahead of time will improve your odds!

Sam, I see no reason to avoid using orange branches or the oleander in your hugelkultur or compost. Just because they are toxic to humans that consume them doesn't mean that they are toxic to your soil and soil organisms. And the amount of oil in the orange will not adversely affect your compost or soil.

On my own farm I have used all sorts of citrus for hugelkultur pits, compost, and mulch. I've used the leaves, fruits, and branches. I've never seen a problem.

Thank  you  Dillon,  for the heads up on  Apple branches.  I have already  cut the branches down and  took out all the leaves.  The branches are fresh, but cut up and  have been soaking in water for few days.  I am planning on using them  also,  since  I do not have many trees to fill up the trench i have dug for the  hugelkultur.   Do you think the apple branches will spout up from 1 foot deep pit  that has been filled 8 inches  with  tree branches and  4 inches  with  my yard  clay soil ?  I  am basically  building a  raised bed on top of this trench that is 1 feet deep.  So, there will be another 1 feet above ground level  that is filled with  my  clay soil + equal  amount of  compost mixed with a  bit of  top soil from Home depot.

The branches  and leaves that i get from the  apple,  oleander and orange trees  can  fill up the trench  but only  barely, if i used all the parts.

I did not know that many trees can root from branches.  Overnight reading about it,  i came to know that this seems to be a common phenomenon (rooting from branches that are fresh cut during spring / early summer).   It will be a pain to dig out 1 or 2 foot  to take out the roots  after  few years.  

I was planning to add 2  inches of  composting  material (food scrapes, leaves that have composted half way)  into this trench of  14 inches.  Will the addition of this help in breakdown of  the branches faster and impede the rooting process by  branches ?   Otherwise my only option is to let the branches  rot for few months and  carry out this project in November, when they are dry completely and dead.  I searched for a faster way to make the branches dead, but they require money investment  and i have already spent a lot on my newbie  backyard garden.  Thanks for suggestions.

Potassium nitrate might be just the thing for speeding up the decomposition process: "stump removers are mostly made of potassium nitrate (KNO3) and act by rapidly increasing the decay of the stump. After an average of 4–6 weeks, the stump will be rotten through and easily fragmented in manageable pieces."
https://en.wikipedia.org/wiki/Tree_stump#Stump_removal
my 2 cents.

Thank you.  That saved my day.  I got a doubt, When i was ready to apply  "high nitrogen fertilizer"  as recommended (either  potassium nitrate or ammonium nitrate).......  If  i apply  this to all the logs and let it sit in moisture for a week,   will that affect the plants that i will be later putting on top of this  raised bed ? I plan to put the plants into hugelkultur bed (as described above)  after 2 weeks or so.  Will the KNO3  kill my plants with high nitrogen (even though i have 1 feet of  soil + compost in between the two ?

Sam Seeking wrote:  Will the KNO3  kill my plants with high nitrogen (even though i have 1 feet of  soil + compost in between the two ?

Hmm..I imagine your veggies will be delighted.

The idea of using  fertilizer came from reading articles on web about "stump removal".   According to  few articles a  high nitrogen fertilizer can be used   since I don't  have  KNO3.  

I have  Scotts Green max.  The label says it is "derived  from  Metheleneureas, Urea, Ammonium sulfate, Potassium sulfate  and iron sucrate (or is it sulfate ? i forget)".  It is a 26-0-2  NPK  formula meant for lawn grass.  

So, the directions say drill holes in the branches,  and fill high nitrogen into it,  and make it wet.  This will promote fungal growth fast which destroys the branch before roots come in.  My new cut branches are 4" to 0.5"  in  diameter.   Can i simply  sprinkle the  high nitrogen fertilizer on top of the  branches in my trench  and  keep it moist for a week in sun to create the fungal growth ?  Then i can fill it up with leaves and soil before  i build the raised bed on top ?

This  forum has been a life saver;  many thanks to all.

Sam Seeking wrote:

So, the directions say drill holes in the branches,  and fill high nitrogen into it,  and make it wet.  This will promote fungal growth fast which destroys the branch before roots come in.  My new cut branches are 4" to 0.5"  in  diameter.   Can i simply  sprinkle the  high nitrogen fertilizer on top of the  branches in my trench  and  keep it moist for a week in sun to create the fungal growth ?  Then i can fill it up with leaves and soil before  i build the raised bed on top ?

This is getting labor intensive but if the idea is to get the nitrogen inside the wood you might consider breaking up the smaller branches and combining them with the leaves and mulch to make a nest. The fertilizer sprinkled onto the nest will attract moisture without you adding water that could leach the concentrate. Then lay the bigger branches in the nest and cover them with untreated soil and mulch.

Thanks for the suggestion.  I did what you suggested. I have 3 different lawn fertilizers that are 23 %  to 29%  range.  How  much of  this fertilizer should i sprinkle  on  a  6 x 3  area (1 ft deep), filled with  

1. apple and oleander  branches  and twigs         50%,  
2. equal parts of  compost  + backyard soil         20%,
3. Home depot  pine bark fine mulch + leaves for 20%,  
4.  last 10%  filled with steer manure compost mixed with my clay soil  (equal parts) ?

Second part of this question is - if  i overdo the nitrogen fertilizer will that burn  my plants  that will be planted in 2 weeks on top of this raised bed ?  I plan to add atleast 8 inches worth of store bought soil (which will be mixed equal parts with my yard soil, which is 50% clay),  on top of this  1 feet hugelkultur bed.

For closure of this thread that i started,  i wanted to  add in what i found out in reading online.  Fertilizer needs  are  explained  in the following  website:

Nitrogen  needs of  various plants

There is no easy  answer to the question  i posted above (which explains the lack of answers).   And i did find out that over fertilizing  can burn plants.  To quote a rule of thumb from above  web link  provided.....
" If a soil test was not conducted, the application of eight ounces (one-half pound) of N per one-thousand square foot of the vegetable garden, prior to planting is recommended. In areas where beans, peas, or other legumes are to be planted the application of N should be avoided as this can reduce the yield of these vegetables.".

So, in  this case, i have decided to add Nitrogen little at a time.  I spread about  0.75 lbs of  lawn fertilizer  on my  24 sq. foot  area.   Since the fertilizer contained about 25%  Nitrogen, that  spread  consisted of  0.25 x 0.75 = 0.19 lb of  Nitrogen.  Note that  all recommendations  take into consideration  that the fertilizer  will  work  for a depth of  6 to 8 inches of soil.   In my  case,  since I  needed Nitrogen to  go into  the  14"  trench,  and  since  Nitrogen  will be depleted by the fresh cut tree branches in hugelkultur bed,   this  over-application  of  N  will be  fine.  To  start  off,  my  garden soil was already depleted of Nitrogen.

I was worried about oleander also, but there was a study that said after 50 days in a compost pile the toxins were gone.  So by the time you Finnish your hugel, and get anything planted, and harvested everything should be fine.

I  am  resurrecting  this  thread after a year,  because  of  what i noticed in the  hugelkultur   layer  of my  raised bed.    This year,  i wanted to bury some more compost before planting  in  May.  Upon digging, i started seeing some green offshoots, and they were  coming  out of  the  Oleander  branches that i buried  last year.   The hugelkultur  was at least 1 feet below the other things sitting on top of it.   The offshoots were small  (about 2 to 3 inches max)  coming out of the  oleander branches,  which tells me that the branches are not completely  dead.  I am watering this area good amount  since  my tomato plants are in this raised bed, needing  good watering in summer.  During winter there is plenty of rain in  SF bay area to keep my clay soil wet  year around  (at a depth of  1.5 feet).    

Now,  my  worry is that  oleander  tree will start spouting  in my raised bed over time,  and consume the nutrients  in the soil   as the offshoots grow.  This year,  i have planted  without disturbing the  branches at the bottom.  I have planted on top of it, after burying some more kitchen waste  in the raised bed.    I thought i will check with this forum,  before  completely  removing the many branches that are the bottom of this  raised bed.  It would require  substantial work in digging up all the top layers, to get to the branches and take them all out.   Please  comment  on what i should be doing  when  my  gardening season is over  at end of fall, and the rains  start in December.   I would like to be better prepared for  March, spring planting in my vegetable garden  (in the backyard of  a typical  home in  SF bay).

Thanks.

Pinging  again,  in the hope for  an answer to previous  question .... Thanks.

Sam I didn't answer your post when I first noticed it hoping someone more knowledgeable would answer you. At this point I hate to leave you hanging, so I will give it my best shot.  I am so sorry you are having this problem!  It is so much work to build a hugelkultur, I hate the thought of having to rip it apart and start over.  The good news is even though every part of the plant is poisonous it doesn't make the soil toxic.  It is still safe to eat fruits and veggies grown in your hugel, just make sure you wash it first.  It doesn't sound like oleander root that easy, you have just some how created the right conditions. As far as I can see you have three main options.  1. Take the hugel apart, and rebuilt minus oleander.  2. Let the oleander grow and ether keep cutting it off at ground level, or pull it out. (I personally don't know how persistent it is.  I have a crap myrtle I removed roots and all ha ha to expand my rose garden.  I have been battling that for years. Before I stopped using round-up I even put that on it several time, I still have to cut, pull, and dig that stupid crape myrtle all summer long.)  3. Do nothing and hope you get a heavy frost that kills the oleander before it grows into something.  I am lazy and always have more to do than time, so for me I would wait and see what happens. If the oleander grows in to little saplings, I would try to pull it out, and if that didn't work, I would cut it at ground level.  I read if you keep cutting the saplings eventually the root looses vigor and dies.  I'm so sorry there is really no good answer.  I still hope someone with first hand knowledge will answer this post for you.  Good luck to you Sam.  Keep us posted and let us know what you decide to do and how it works out for you.  

Jen.   You are  right - i put in lot of work  to build that  hugel  at bottom.   It  will be equally  hard to  pull it apart  and  take out the branches  at bottom that are still alive.  The only mistake i did was  to  bury  the  oleander  branches  that i  had  cut down  (and it was drying in  CA  hot sun for 2 weeks),  thinking that  they would die underneath.  This  CA  oleander  is  as bad as a weed,  keeps growing and  taking  nutrients from my other trees nearby.  The branches  (similarly)  are  sucking  nutrients from my  raised bed  compost  and  trying to  grow roots  at  1  feet  below  soil.  I have seen them take root in  other parts of my garden, and they will not  die  if  i keep taking out the  saplings above soil.  Typically,  my  gardening is done  in fall, and nothing happens  there during winter.   So, i may  dig  it all up  to be safe, when the season is over.   Thanks for your  thoughts.  

Lesson  for  others  who  happen  on this thread in future ...... Never  bury  anything  that is not  completely  dry (atleast  an year  old, cut branches that have dried out in summer sun).

The  need to  remove  those  oleander  branches  became  clear  last week.   I saw  offshoots  coming above  ground now,  since i have been watering for past month  (and planted my raised bed with vegetables).  So, even when dried in sun for  about a month,  oleander  branches  do not  dry  out enough  to be buried.  For now,  i have  cut out  the offshoots, and  plant to   dismantle  the  whole  hugelkultur  bed  after  rains, in march.  Just wanted to update this thread,  in case someone searches for this in future.