Replace the greenhouse soil or wash it: don’t strip the shed at the first white crust
Washing with a drain is cheaper than a truck of new soil — if the salt can leave.
- Frost under film, more wilt after watering.
- Someone wants the soil hauled out.
- Start with an EC meter.
- Heavy disease or nematodes sometimes need new soil or a mix; salt alone is washed first.
- Worse after every feed is not a shortage.
- Don’t strip the house without EC; don’t refill and keep the old recipe.
- Soil EC: Stricter at seedling. Over the line, wash first. Follow the local vegetable safety band
- Name what you see before you feed.
- If leaves, roots and the surface disagree, stop.
What you see in the field
Frost under film, more wilt after watering. Someone wants the soil hauled out. Start with an EC meter.Squat on the whitest, worst strip and scrape the crust. Compare with a neighbour that is still green. White crust plus scorched margins count; wilt without a crust may just be drought. Note whether the ditch actually runs.
Tap to enlarge. The caption says what to photograph. Missing field photos are marked as to-be-added.
Why it looks like this
The field looks like this because the root cannot take water or nutrients the usual way. Fix the soil condition first — drainage, salt, acidity, compaction or a salt of fertiliser — then a thin feed. Rates live in the range on this page; confirm with a local station and the label.
Easy to mix up
Looks like “Soil-borne disease that must have new soil”
Heavy disease or nematodes sometimes need new soil or a mix; salt alone is washed first.
Looks like “Short of fertiliser”
Worse after every feed is not a shortage.
Do this / don’t do that
- 1Compare the worst plants with a neighbour ridge. Photograph whole plant, close-up and soil surface before you add fertiliser.
- 2Match roots, leaves and the soil surface to this guide. If they do not line up, do not copy a bag count.
- 3Use the rate range on this page only as a range. Confirm with a local station and the product label.
Don’t do this first
- Don’t strip the house without EC; don’t refill and keep the old recipe.
Rate range
Soil EC
Stricter at seedling. Over the line, wash first
Follow the local vegetable safety band.
Change the soil
The last resort
New soil with the old habit is a wasted change.
These are ranges. Confirm with your local extension station and the product label.
When you see Frost under film, test. Mix several spots of the tilled layer; skip the edge and the manure heap.
Lesson video
2026-03-11 · Li Zeyu · For learning. Serious damage: local agronomist or a soil test.
For learning only. Fertiliser and pesticide decisions need a local agronomist and a soil test.
Not sure? Photograph the field to identify the problem