Food Forest: planting between mature trees

This a seemingly straight forward question but I can't find info in any permaculture books I have......In general I am looking for spacing info when designing food forests...In particular a food forest based off existing mature trees vs starting with small trees. Is there a rule of thumb on placement of the shrub layers under trees? In my particular case I have mature black walnuts I am building around. If the shrub layer sits under the drip line it seems there is alot of "wasted" space at the foot of the trees? Also if designing with young trees I know it will transition over time but would the shrub layer be best palced at the expected mature drip line?

Hi organick McCoy
initially you are in a spacial race with the weeds if you win the race the gain the potentially productive space with very little need for maintenance work. I love to ridiculously over stack new systems and have a surplus chop and drop mulch to feed the soil.

The first major return of surplus I think we should concentrate on and aim at in food forest establishment is organic matter, fast carbon pathways of return by design.

Once establishment starts to evolve refined sophisticated placements can be selected to occupy very specific niches.

Time gains are a prize if soils are being created as a by product of our actions.

Hi OM

I'm not experienced with food foresting but black walnuts are allelopathic. They exude boichemicals into the soil that stunt or prohibit the growth of many plants. Maybe research into edible plants resistant to to the walnut would work...

Heres some good info on allelopathy: http://en.wikipedia.org/wiki/Allelopathy

I know you are dealing with existing trees, but some permaculture food forest books suggest even planting a nitrogen fixer in the SAME HOLE. So I guess that they would also be suggesting that they are ok really close..obviously.

I would say it depends on the tree and it's adult size. If it is a very large tree such as the black walnut, for one thing the sun will reach quite deeply below it esp in spring and fall, so as long as any plants that require sun get it, it shouldn't really matter. ..unless of course it doesn't work with the juglone.

As for shorter trees or suckering trees there may be a need to space wider..esp if it makes harvesting difficult. If the understory doesn't interefere with harvest and doesn't grow up into the original tree, to where it will damage the branches, close should be OK.

perennials that die down to the ground in the fall can be nearly anywhere, be careful of thorney bushes with trees you'll be harvesting from, maybe just use them as a hedge beyond the dripline.

The Ontario wild black raspberry does well with walnuts and so does elaeagnus umbellata. In my forest in Puebla I've had to plant close because plants on there own tend to die during the cold dry winters there. Shelter can be a good thing.

Geoff Lawton wrote:Hi organick McCoy
initially you are in a spacial race with the weeds if you win the race the gain the potentially productive space with very little need for maintenance work. I love to ridiculously over stack new systems and have a surplus chop and drop mulch to feed the soil.

The first major return of surplus I think we should concentrate on and aim at in food forest establishment is organic matter, fast carbon pathways of return by design.

Once establishment starts to evolve refined sophisticated placements can be selected to occupy very specific niches.

Time gains are a prize if soils are being created as a by product of our actions.

Overstacking for organic matter makes tons of sense.....Comfrey, daikon radish....what are some other great plants to use for this? N fixing cover crops?

Brenda Groth wrote:I know you are dealing with existing trees, but some permaculture food forest books suggest even planting a nitrogen fixer in the SAME HOLE. So I guess that they would also be suggesting that they are ok really close..obviously.

I would say it depends on the tree and it's adult size. If it is a very large tree such as the black walnut, for one thing the sun will reach quite deeply below it esp in spring and fall, so as long as any plants that require sun get it, it shouldn't really matter. ..unless of course it doesn't work with the juglone.

As for shorter trees or suckering trees there may be a need to space wider..esp if it makes harvesting difficult. If the understory doesn't interefere with harvest and doesn't grow up into the original tree, to where it will damage the branches, close should be OK.

perennials that die down to the ground in the fall can be nearly anywhere, be careful of thorney bushes with trees you'll be harvesting from, maybe just use them as a hedge beyond the dripline.

I have read about the bullock brothers always using the N fixer in same hole.....I just used some goumi with persimmon trees I planted this year. I was under the impression that the nitrogen fixers are eventually shaded out, highly pruned, or fully cut out?

For second succession N-fixers you might look into bayberries or any eleagnus species if they work in your area. Those are both Actinorhizal nitrogen fixers (using a fungal, rather than bacterial, symbiont), and are supposedly more efficient, they also both provide a useful yield. Another thing to consider is leaving only a low growing herbaceous layer directly under the walnut to facilitate walnut harvesting, I've seen day lilies grow vigorously under them and those are a decent food source all year.

peace

interesting about the daylillies under the walnuts as I have TONS of daylillies that are desperately waiting to be divided..I'm bad.

Tim, I just read your question....I do not know if this is still helpful. Maybe this will help someone else.

I lived where there was a huge black walnut tree, 3 stories high. The land steward there had added a lot of organic matter, according to his report, so he could plant under it. I do not know what quantities or type of organic matter. This was on the side of an extinct volcano - the soil was a dream - highly mineralized.

I saw, growing in health under this black walnut tree, within the drip line: comfrey; lemon balm; a 15 foot cedar tree; a two story camelia bush; 3 small pine trees; profuse ivy; irises; star-gazer lilies; daylilies; daphne odora; jerusalem artichokes; 20 feet from the trunk, under the drip line, was a thriving 14 foot high rhododendron; perennial sweet peas; raspberries; columbine; rose campion; lamb's ear; euphorbia; ferns; scilla.

Some of these are ornamental, but I include them to stretch people's opinion that black walnuts are allelopathic.

Best of luck.

Pamela

Martin Crawford's Creating a Forest Garden has excellent spacing ideas for shrubs under trees. Edible Forest Gardens has a table of species that grow fine with black walnut juglone.

Thanks, Eric. And thank you for your awesome books. I love them, and consult them often. Love and Gratitude and Blessings