At least 3 m²32 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 × Blackberry
1 × Russian comfrey
8 × White clover
3 × Yarrow
The real placement. The drip-line rings need about 7 ft across, and the planner draws the same layout.
How it works: The flowers supply nectar and pollen that adult predators and parasitoids feed on, so a patch of them near a fruiting crop keeps those beneficial insects fed and close by to work the crop. The effect is real but not guaranteed. An insectary patch does not always suppress pests.
Evidence: checked against 1 source in the research-based literature.
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.
Cutting the mulch plant and leaving it where it falls (chop-and-drop) returns its potassium-rich leaves to the surface as mulch
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].
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.
If you skip this, you lose real yield. The planner warns you.
How it works: Verticillium dahliae persists in soil as microsclerotia and infects a wide host range spanning nightshades and rose family. There is no in-ground cure once a susceptible perennial is planted, so it can wilt and die from inoculum an earlier host left behind. Because the reservoir family may differ from the victim's, the same-family rotation intervals miss it.
Evidence: checked against 3 sources in the research-based literature.
Verticillium wilt is caused by two common soilborne fungi (Verticillium dahliae and Verticillium albo-atrum) that have a wide host range
www.umass.edu
Brambles - DiseasesUMass Extension, New England Small Fruit Management Guide
Verticillium attacks a wide range of plants, including potatoes, tomatoes, peppers, eggplant and strawberries. It overwinters in the soil and on plant debris. Do not plant [raspberries following these crops].
Verticillium Wilt of Tomato and Eggplant NC State Extension
Verticillium Wilt of Tomato and Eggplant
Remedy
Site the perennial on ground with no recent nightshades, or choose one that is not Verticillium-susceptible. Extension advises growing a non-host (corn or a small grain) for at least two years first, without claiming that clears the soil. Once the perennial is planted there is no in-ground cure.
