Crop care in Project Zomboid

Every crop has a minimum soil water level it needs at the end of each growth stage. Most seeds want 70 or 80 percent to sprout, and many crops need less once they are past the first stage. Barley, for example, drops from 70 to 30. Exact figures are on crop data.

When a stage ends, the game compares the soil to that target. At or above it, the plant grows on time. A small shortfall (up to about 10 percent) delays the next stage by a few hours. A bigger gap stalls growth, and a large gap stalls it longer and costs health. A sprouted plant that reaches zero water dies outright.

On default Plant Resilience, soil loses about 1 point every 5 hours, roughly 5 a day (one source), and each pour from a can adds 10 (one source). Sunny weather, pest flies and weeds on the tile all speed up the drain. Rain waters outdoor plots quickly, even light rain, so check the weather before a watering round. Tainted water is fine for plants, so a rain barrel or river works (see water).

Sources disagree on overwatering. One Build 42.21 guide says no vanilla crop can be overwatered; another says some crops lose health from too much water. Keep the soil at or a little above the target.

Bagged fertilizer and compost both use the same Fertilize action on a planted crop, and the count resets each growth stage. One dose per stage is the safe rule.

Weeds on the tile halve the speed boost and block the bonus-yield roll. Compost gives the same single boost; extra bags in the same stage do nothing. One guide says fertilizer gives no benefit in winter when seasons are on (one source).

Making compost. Build a composter from the Farming build menu with 4 planks, 4 nails and a hammer. The basic version needs Carpentry 3 and the better one Carpentry 6 (older guides list Carpentry 2, which is Build 41). See carpentry. Drop in rotten food or animal dung; fresh food waits until it rots. Corpses do not compost in vanilla. Default compost time is 2 weeks on most presets and 1 week on Outbreak, set by the Compost Time sandbox option. The bin holds up to 100 points. Right-click and choose Get Compost with an empty sack. A full Compost Bag holds 4 uses (one source).

Build 42 has four plant problems: mildew, aphids, pest flies and slugs. Devil's Water Fungi was a Build 41 disease and pzfans says it is not in the current list, though one database page still names it. There is no leaf spot disease. Rot is not a disease: it happens to crops left unpicked past their seed stage.

• Mildew: the only problem that slows growth. From level 10 each stage is delayed, at 30 growth stops and at 60 the plant dies. It spreads faster on dry plots.
• Aphids: every 10 points removes one item from the harvest. They like well-watered plants and fade in dry spells and winter.
• Pest flies: drain extra water and do not change the sprite, so watch for plots that dry out fast.
• Slugs: every 10 points removes one item from the harvest. Tomatoes, potatoes and radishes never get them.

New infections become likelier as the soil falls below its target, and weeds double the chance.

Each finished spray has 10 uses (one source). Sprays do not cross-cure. Each use removes 10 points plus your Agriculture level, so heavy cases need several sprays. The recipes come from the Farmer job, the Gardener trait, farming magazines, or reaching Agriculture 6.

Companion planting is the main prevention. Once a companion reaches stage 3 it protects neighboring plots: chives, garlic and marigold keep aphids off, and basil and sage keep flies off. It does not cure a plant that is already sick.

The sprite turns unhealthy when health or water drops under 50 or a pest reaches 10, and shows as dying under 25 or when a pest reaches 30.

Build 42 has no separate weed plant. Grass, bushes and vines on a plot's tile do the job: they double water loss, halve the benefit of rain and fertilizer, and double disease chance. Clear the ground before you dig.

With the Plant Growing Seasons sandbox option on (the default except on Outbreak), sowing outside a crop's months makes it cursed. In a risky month the curse chance is (11 minus Agriculture level) in 20. Outdoors, a crop in its bad month, or in winter unless it is cold-hardy, also becomes cursed. A cursed plant loses health twice as fast when dry or sick. The cold-hardy crops are cabbage, kale, garlic, leek, wheat, barley, rye, flax and wild garlic. Indoor crops escape the bad-month and winter curses, but not the wrong-month sowing curse. Sowing calendars are on seasons and crops, and cold-weather planning on winter.

pzfans gives this breakdown for Build 42:

Another guide puts the thresholds at different levels (clearer disease names at 4, exact hours at 8), so check in game. Holding a magnifying glass is said to add 2 levels for disease info (one source). Each level also adds starting health when sowing. The Farmer job starts at Agriculture 4. Books and other ways to level are on skill books and traits and occupations.

Opinion: until you reach level 3, walk your plots every morning and spray anything with an unhealthy sprite rather than waiting to diagnose it.

Crops pass through a harvest stage, then a seed-bearing stage, then rot. Grains bear seed at the harvest stage itself. Picking a seed-bearing plant gives seeds equal to half the produce, rounded down, with at least one. A seed packet opens into 5 seeds. About 17 crops, including basil, mint and rosemary, regrow after harvest instead of being used up (one source).

Opinion: keep one or two plants of each crop for seed and harvest the rest for food at the normal stage. Store spare produce using food preservation. The basics of digging plots are on the main farming guide.