At least 6 m²65 ft². If your bed is smaller, the planner grays this plant team out, says why, and offers the nearest adaptation that fits. It never swaps in something else without telling you.
What it looks like planted
1 × Grape
33 × Daffodil
The real placement. The drip-line rings need about 10 ft across, and the planner draws the same layout.
Between seasons
The whole planting stays in place year-round.
What it claims
Bulb ring suppresses turfgrass competition at the stem
Mulch generously to keep the roots cool and moist, build soil organic matter, and discourage weeds.
What to keep in mind
The grapevine needs a trellis or arbor, assigned here as its support, and casts shade once established, so the understory stays sparse, with a bulb ring at the posts and no full insectary. The arbor structure is the center of this team; the vine is trained onto it, so the structure stands where a tree would, which is how this team answers "a ring with no tree at the middle". A hardy kiwi arbor wants a male and a female vine, so plan on about 9 m² and a stouter structure than a grapevine needs; the vine is far heavier.
Who does what, and the swaps
Each job in this planting can be done by more than one plant. The usual choice comes first, and each swap says what it costs.
If you skip this, you lose real yield. The planner warns you.
How it works: Many fruit trees carry self-incompatibility alleles at a single locus. When a pollen grain shares an allele with the pistil it lands on, the pistil rejects it and no seed sets. A plant's own pollen always shares its alleles, so it cannot fertilize itself. Neither can a second tree of the identical variety, which is genetically the same. Fertilization needs pollen from a genetically distinct plant.
Evidence: checked against 2 sources in the research-based literature.
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.
