Milpa Gardens

Fruit Tree Guild (Dwarf)

A perennial guild - a standing planting, not lifted between seasons.

The fruit-tree guild on a dwarfing rootstock — the standard small-yard adaptation.

Space it needs

At least 9 m². A bed smaller than that does not get this guild quietly substituted for something else — the planner greys it out, says why, and offers the nearest adaptation that does fit.

Adapted from Apple Guild.

Between seasons

The guild is the standing planting; it is not lifted at all.

What it claims

a dwarfing rootstock holds the tree to ~2-2.5 m, fitting the whole guild into a small yard

Well established

a dwarf rootstock is poorly anchored, so the tree needs permanent staking

Well established

bulb ring suppresses turfgrass competition at the trunk

Well established

Mechanism: Resource competition and physical occupancy of the root collar zone.

Evidence: settled without a trial - competition.

understory insectary improves predator presence

A good hunch

Mechanism: Nectar and pollen resource provisioning.

Evidence: confirmed against 1 source in the research-based literature.

the source

UC Statewide IPM Program (UC IPM), 'Insectary Plants', ipm.ucanr.edu/environmental-protection-and-pesticide-stewardship/insectary-plants (read 2026-07-11): 'Insectary plants are those grown to attract, feed, and shelter insect parasites (parasitoids) and predators to enhance biological pest control. Insectary plants provide nectar and pollen, which the adults of many natural enemy species need to consume.' (UC IPM also notes 'insectary plants may not always help' suppress pests — consistent with the grade-C 'reasonably supported' framing.)

chop-and-drop mulch cycles K and builds soil organic matter

A good hunch

fixer feeds the tree in-season

Refuted

Evidence: confirmed against 3 sources in the research-based literature.

the 3 sources

Univ. of Arkansas Extension, 'Creating a Three Sisters Garden', uaex.uada.edu (read 2026-07-11): 'Most of the nitrogen converted by the beans will not be available to the corn and pumpkins the first year; the bean roots have to break down to release nitrogen. Corn is a heavy nitrogen [feeder].'

Hupe et al. 2021, Sci Rep 11:11424, 'Evidence of considerable C and N transfer from peas to cereals via direct root contact but not via mycorrhiza', pmc.ncbi.nlm.nih.gov/articles/PMC8169652 (read 2026-07-11): reports 'a mean N transfer rate of 8.4%, with a range of 2.7 to 22.5%, ... from N2-fixing legumes to non-N2-fixing mycorrhizal cereals' and 'N transfer rates of between 3.1 and 6.0% ... from soybean to maize'.

'Nitrogen uptake and transfer in a soybean/maize intercropping system in the karst region of southwest China', pmc.ncbi.nlm.nih.gov/articles/PMC5648690 (read 2026-07-11): 'N transferred from soybean to maize account for 2.4%–3.3% of the N uptake of maize.'

The honest version

A footprint adaptation, not a different guild: the mechanisms are the fruit-tree guild's, on a smaller tree. The dwarfing rootstock is what makes it fit — and what makes the tree dependent on permanent support.

Roles

A role is filled by whatever satisfies its predicate, not by a fixed species list. The canonical filler is the default; the alternatives are priced.

Canopy

Fixer

Mulch producer

Bulb ring

Insectary

Rules that gate it

Perennial woody guilds are not bed-scoped. Their ground entity is the drip-line ring.

Well established · suboptimal if ignored → advise

Mechanism: A tree's root zone expands for a decade and extends well past the canopy edge.

Evidence: settled without a trial - root architecture.

See this rule in the planner

Do not plant a juglone-sensitive species within the root zone of Juglans. The sensitive list is the hazard's own, and it is wider than the nightshades - it also carries apple and cabbage.

Well established · fatal if ignored → block

Mechanism: Juglans roots exude hydrojuglone, oxidized to juglone, a respiration inhibitor. nightshades are highly sensitive: wilt and death.

Evidence: confirmed against 2 sources in the research-based literature.

the 2 sources

UW-Madison / Wisconsin Horticulture (Joy, Hudelson & Jull, rev. 2024-02-28), 'Black Walnut Toxicity', hort.extension.wisc.edu/articles/black-walnut-toxicity (read 2026-07-13): 'Vegetables such as tomato, potato, eggplant and pepper ... are particularly sensitive to juglone'; 'The toxic effects of a mature black walnut tree can extend 50 to 80 feet from the trunk of the tree, with the greatest toxicity occurring within the tree's dripline.'

Iowa State Univ. Extension & Outreach, Yard and Garden FAQ, 'What plants are sensitive to the juglone produced by black walnuts?', yardandgarden.extension.iastate.edu (read 2026-07-13): juglone-sensitive plants include 'members of the tomato family (tomato, potato, eggplant, pepper).'

remedy

Plant it outside the walnut's root zone — the whole drip line and beyond. There is no soil treatment for juglone.

See this rule in the planner

Self-incompatible species require 2+ genetically distinct plants.

Well established · costly if ignored → warn

Mechanism: Self-incompatibility alleles prevent fertilization by own pollen.

Evidence: confirmed against 2 sources in the research-based literature.

the 2 sources

Penn State Extension, 'Pollination Requirements for Various Fruits and Nuts', extension.psu.edu/pollination-requirements-for-various-fruits-and-nuts (read 2026-07-11): 'Apple: Cross-pollination is always needed to produce adequate fruit crop'; 'Cherry: Sweet: Most varieties are self-unfruitful'; 'Those fruits listed as self-fertile will set fruit with their own pollen.'

'Pollen-Pistil Interaction in Response to Pollination Variants in Subtropical Japanese Plum (Prunus salicina Lindl.) Varieties', PMC9692414, pmc.ncbi.nlm.nih.gov/articles/PMC9692414 (read 2026-07-11): 'Japanese plum exhibits gametophytic self-incompatibility (GSI), a prezygotic reproductive barrier where genetically related pollen is rejected by the pistil ... governed by a polymorphic locus (S) ... Self-incompatibility occurs when the same S-allele is expressed in the haploid pollen grain and the diploid pistil.'

remedy

Plant at least two, and where the species needs a second cultivar make them different varieties — two of the same will not pollinate each other.

See this rule in the planner

All guilds