A direct-sown root crop left unthinned grows crowded roots that stay small
A direct-sown root crop left unthinned grows crowded roots that stay small. The seedlings stand far denser than they can mature and compete for the same soil, and the roots twist and intertwine and never size up.
Promising A person has checked it against its sources. If you skip this, it still grows, just less well. The planner suggests it.
How it works
Root crops are sown as seed in place and germinate much denser than they can mature. Where the seedlings stand too close, their swelling roots run out of room and compete for space, water, and nutrients, so they stay undersized and are deformed, twisting and intertwining against their neighbors. Thinning the stand while the seedlings are young leaves each remaining root the room to develop. (This is distinct from FORKING, which the sources attribute to rocky or compacted soil and root-knot nematodes. So this rule claims small-and-intertwined roots and makes no claim about forking.)
What to do about it
Thin while the seedlings are young, about 2.5 cm (one inch) tall, to the crop's spacing. Pull or snip the extras so the row isn't left solid, to roughly one seedling every 2.5-5 cm for a full-size carrot, wider for parsnip and the larger varieties. The pulled thinnings of carrot are edible, tops and all.
How much it matters: No yield figure is stated or estimated. The penalty is smaller roots, and the crop does not fail; because the outcome depends on how thickly the gardener sows and whether they thin, the rule only advises.
The evidence
Evidence: checked against 2 sources in the research-based literature.
The 2 sources
You must thin out both carrots and parsnips to allow room for the roots to develop properly
Twisting and intertwining result from seeding too thickly and inadequate thinning of seedlings
Plants it applies to
How this rule has changed
Every change is dated, newest first. The full record, with each reason, is in the data download.
- Wording made clearer
- Added to the rules
Cite this page
Milpa Gardens. "A direct-sown root crop left unthinned grows crowded roots that stay small. The seedlings stand far denser than they can mature and compete for the same soil, and the roots twist and intertwine and never size up." Evidence grade: Promising. https://milpa.garden/rules/direct-sown-root-crop-left-unthinned-grows/
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- Well established
- The rule names its mechanism and is settled, by sources a person has read and checked or by plain arithmetic and geometry.
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- Plausible by its mechanism, but field studies are thin, so treat it as a lean.
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