Overview
King Water Chestnut is an herb crop in Starsand Island, described in-game as "these giant water chestnuts are as big as a sandbag, yet they retain the same delicate flavor and crisp texture as their smaller counterparts." It is a premium crop that unlocks at the Expert Farmer tier of the Farming profession. King Water Chestnut grows during Autumn and Winter, takes 8 days and 12 hours to mature, and produces 4 King Water Chestnut per harvest.

With a gold-per-day return of approximately 186.1 g/day, King Water Chestnut is tied with Zapweed as the most profitable Paddy Field crop at the Expert tier. Both crops share identical stats (790 Coin seed cost, 593 Coin sell price, 4 yield, 8.5-day growth), but they cover different seasons. King Water Chestnut handles Autumn and Winter, while Zapweed handles Summer and Autumn. Together they allow Expert Farmers to keep Paddy Fields generating top-tier income across three seasons.
Because King Water Chestnut grows in a Paddy Field, it does not require manual watering. The standing water in the flooded plot provides constant irrigation, saving daily time and stamina. This is especially valuable given the crop's 8.5-day growth cycle, as you can plant and leave it alone until harvest day.
Quick Stats
Attribute | Value |
|---|---|
Type | Herbs |
Season | |
Growth Time | 8 days 12 hours |
Yield per Harvest | 4 |
Harvests | 1 (single harvest) |
Plot Type | Paddy Field |
Seed Cost | 790 Coins |
Sell Price | 593 Coins (per King Water Chestnut) |
Farmer Tier | Expert Farmer |
Seed Source | |
Watering | Automatic (Paddy Field) |
Profit per Harvest | 1,582 Coins |
Gold per Day | 186.1 g/day |
How to Obtain Seeds
King Water Chestnut Seeds are sold by Graminova at the Happiness Seed Shop for 790 Coins per seed bag. You must reach the Expert Farmer tier before King Water Chestnut Seeds appear in the shop inventory.
To unlock Expert Farmer, you need to complete every previous tier's certification trials (Novice, Apprentice, Intermediate, Junior, Senior) and then pass the Expert Farmer trial given by Graminova. This requires extensive farming experience and completion of numerous farming milestones across all earlier tiers. Once you earn the Expert Farmer certification, King Water Chestnut Seeds (along with other Expert-tier seeds like Zapweed, Fluffbean, Chirpy Plum, Honeyvine, Star Mango, Star Plum, Jadelume, Stardew Fern, Exotic Egg, and Bell Pepper) become permanently available for purchase.
Seeds are not locked by season at the point of purchase. You can buy King Water Chestnut Seeds during any season and stockpile them for the next Autumn or Winter planting window. This is a practical strategy near the end of Summer when you want to prepare for the upcoming growing season.
An alternative way to obtain King Water Chestnut Seeds is through the Grinder. Loading 2 King Water Chestnut into the Grinder will produce King Water Chestnut Seeds, allowing you to recycle part of your harvest back into planting material. You can also occasionally find seeds through general exploration by chopping trees and shrubs, foraging weeds, and opening Treasure Chests scattered across the island.
Growing King Water Chestnut
King Water Chestnut requires a Paddy Field for planting. It cannot be grown on standard Farmland, Trellises, or Planting Boxes. Paddy Fields are flooded planting areas that you can construct on your farm. To plant King Water Chestnut, select the seeds from your inventory and place them into an available Paddy Field plot.
Once planted, King Water Chestnut takes 8 days and 12 hours to fully mature. Because Paddy Fields keep the soil permanently flooded, King Water Chestnut does not require manual watering. The standing water counts as constant irrigation, which saves significant time and stamina compared to Farmland crops that need daily watering. This is one of the main advantages of Paddy Field crops.
King Water Chestnut is a single-harvest crop. After you pick the 4 King Water Chestnut, the plant is consumed and the Paddy Field plot becomes empty. You must replant from seed if you want to continue growing King Water Chestnut in that spot. This is the same behavior as other Paddy Field crops like Rice, Water Caltrop, and River Lotus.
Seasonal Availability
King Water Chestnut grows in both Autumn and Winter. Each season lasts 28 in-game days, giving you a total window of 56 days across both seasons to grow this crop. With a growth cycle of 8.5 days (8 days 12 hours), you can complete up to 6 full harvests within the two-season window if you replant immediately after each harvest.
Plan your planting carefully to avoid wasting seeds at the end of Winter. If you plant King Water Chestnut with fewer than 9 days remaining in Winter, the crop may not finish growing before the season changes to Spring. Any immature crops left in the ground when the season ends will not progress. Start your final planting no later than day 19 of Winter to be safe.
Paddy Field Mechanics
Paddy Fields are specialized farming plots that hold standing water. They unlock through the Farming profession progression and can be built using materials gathered around the island. Other crops that share the Paddy Field requirement include Water Spinach, Sugarcane, Rice, Corn, Water Caltrop, River Lotus, and Zapweed.
Since Paddy Field crops do not need manual watering, they free up time that you can spend on other activities. This is especially valuable for King Water Chestnut because its 8.5-day growth cycle means you do not need to visit the plot at all between planting and harvesting. Simply plant, wait about 8 and a half days, harvest, and replant. If you are building a large-scale farming operation, dedicating several Paddy Field plots to King Water Chestnut is one of the most profitable uses of that space during Autumn and Winter.
Sell Prices
Each King Water Chestnut sells for 593 Coins. Since one seed (790 Coins) produces 4 King Water Chestnut, a single harvest yields 2,372 Coins in revenue, for a net profit of 1,582 Coins per seed.
For higher returns, consider selling your harvest to the Merchant Ship when it docks at Starsand Town. The Merchant Ship pays roughly double the standard vendor price for all goods, which would push King Water Chestnut revenue to around 1,186 Coins per unit. Timing your harvests to coincide with the ship's visits maximizes your earnings significantly.
Profitability Analysis
King Water Chestnut is one of the top earners at the Expert Farmer tier. Its gold-per-day calculation works out to approximately 186.1 g/day, tying it with Zapweed for the highest daily return among Expert Paddy Field crops. The table below compares King Water Chestnut with other Expert Farmer tier crops.
Crop | Season(s) | Growth Time | Yield | Seed Cost | Sell Price | Profit/Harvest | Gold/Day |
|---|---|---|---|---|---|---|---|
King Water Chestnut | Autumn, Winter | 8d 12h | 4 | 790g | 593g | 1,582g | 186.1 |
Summer, Autumn | 8d 12h | 4 | 790g | 593g | 1,582g | 186.1 | |
Spring, Summer | 7d 12h | 4 | 730g | 505g | 1,290g | 172.0 | |
Spring, Summer | 7d 12h | 4 | 730g | 505g | 1,290g | 172.0 | |
All Seasons | 7d 18h | 4 | 700g | 490g | 1,260g | 162.6 | |
Spring, Autumn | 7d 18h | 4 | 700g | 490g | 1,260g | 162.6 | |
Spring, Autumn | 7d 12h | 4 | 750g | 518g | 1,322g | 176.3 | |
All Seasons | 7d 18h | 4 | 690g | 483g | 1,242g | 160.3 |
King Water Chestnut and Zapweed form a strong pairing for extended Paddy Field income. Zapweed covers Summer and Autumn while King Water Chestnut covers Autumn and Winter. During Autumn, both crops can be planted simultaneously for maximum output. By rotating between the two, you can maintain top-tier Paddy Field earnings from Summer through Winter (three of four seasons). For Spring, you can fall back on Senior-tier Paddy Field crops or switch your Paddy Fields to other uses.
Compared to Fluffbean, which grows on standard Farmland in all seasons and earns 162.6 g/day, King Water Chestnut offers 23.5 more gold per day. However, the two crops do not compete for the same plot space since King Water Chestnut requires Paddy Fields while Fluffbean uses Farmland. Growing both simultaneously is the optimal strategy if you have both plot types available.
For a full breakdown of all crop earnings, see the Crop Profitability Rankings page.
Processing Options
King Water Chestnut has limited processing options compared to some other crops. It has no known cooking recipes as a direct ingredient, but it can still be converted into useful materials.
Station | Input | Output | Notes |
|---|---|---|---|
2 King Water Chestnut | King Water Chestnut Seeds | Recycle harvested crop into planting material | |
2 King Water Chestnut + 2 Salt Brick | Pickled King Water Chestnut | Preserved herb; Pickling Jar unlocked at Intermediate Farmer |
The Grinder converts 2 King Water Chestnut back into King Water Chestnut Seeds. Since the seeds cost 790 Coins and each unit sells for 593 Coins, recycling 2 units (worth 1,186 Coins in sales) to save 790 Coins on a seed bag is not cost-effective under normal circumstances. Purchasing seeds from the shop is generally the better option unless you are short on Coins and have surplus crops.
Pickled King Water Chestnut is produced at the Pickling Jar, which unlocks at the Intermediate Farmer tier. The process requires 2 King Water Chestnut and 2 Salt Bricks. Pickled King Water Chestnut can be used as a gift or sold for additional income.
Unlike many vegetable and fruit crops, King Water Chestnut does not appear in any known cooking recipes. Its primary value is in selling the raw harvest for Coins rather than processing it into cooked dishes. This makes King Water Chestnut a straightforward cash crop: plant, harvest, sell.
Gifting Preferences
King Water Chestnut is a moderately popular gift among island residents and animals. Giving King Water Chestnut to a character who loves it provides a significant boost to your friendship level. Below are the known preferences.
Preference | |
|---|---|
Loved | |
Liked | Most other characters |
Neutral | Dog, Panda |
Disliked | Cat, Ferret |
Since Graminova loves King Water Chestnut and she is the Farming profession mentor, gifting her King Water Chestnut is a convenient way to raise friendship while you are already visiting the Happiness Seed Shop to buy seeds. Marston, Matilda, and Sagewood are also good gifting targets if you encounter them during your daily routine.
Everlasting King Water Chestnut Seeds
Like all crops in Starsand Island, King Water Chestnut has an Everlasting variant. Everlasting King Water Chestnut Seeds produce a plant that does not disappear after harvest. Instead, the crop regrows and can be harvested again without replanting, eliminating the need to buy new seeds each cycle.
There are several ways to obtain Everlasting King Water Chestnut Seeds:
Islandpedia Rewards: Completing certain entries in the Plants section of the Islandpedia may reward you with Everlasting Seeds for specific crops.
Eternal Blessings Skill: The Senior Farmer tier unlocks the Eternal Blessings skill, which gives a chance of receiving an Everlasting Seed when harvesting any regular crop. The higher your farming proficiency, the better the odds.
Random Harvest Drops: Occasionally, harvesting a normal King Water Chestnut plant will yield an Everlasting King Water Chestnut Seed alongside the regular produce.
Everlasting Seeds are safe to relocate. If you remove an Everlasting crop from its plot, the seed returns to your inventory so you can replant it elsewhere without losing your investment. Over time, building up a collection of Everlasting King Water Chestnut Seeds lets you maintain a permanent King Water Chestnut field that produces herbs every 8.5 days without any ongoing seed costs.
Given the 790 Coin seed cost (one of the highest in the game), Everlasting Seeds are especially valuable here since they eliminate a major recurring expense. The everlasting gold-per-day rate for King Water Chestnut is approximately 279.1 g/day (2,372 Coins revenue divided by 8.5 days with zero seed cost), a substantial increase over the standard 186.1 g/day.
Everlasting Seeds also ignore season restrictions, meaning your Everlasting King Water Chestnut will continue to grow and produce harvests even during Spring and Summer. This transforms King Water Chestnut from a two-season crop into a year-round income source, further boosting its already excellent profitability.
Tips
Pair with Zapweed for extended Paddy Field income: King Water Chestnut covers Autumn and Winter while Zapweed covers Summer and Autumn. Running both crops in your Paddy Fields gives you top-tier earnings across three of four seasons.
Overlap during Autumn: Both King Water Chestnut and Zapweed can grow in Autumn. If you have enough Paddy Field plots, plant both crops during Autumn for maximum output from that season.
Build extra Paddy Fields before Expert Farmer: Prepare Paddy Field plots in advance so you can plant King Water Chestnut immediately upon unlocking Expert Farmer. More plots means more simultaneous harvests and higher total income.
Time your last planting of Winter carefully: With an 8.5-day growth time, make sure you plant your final batch no later than day 19 of Winter to guarantee the harvest completes before Spring begins.
Gift King Water Chestnut to Graminova: She loves it, and you are already visiting her shop for seeds. Raising her friendship level unlocks additional rewards and dialogue.
Prioritize Everlasting Seeds: King Water Chestnut is one of the best candidates for Everlasting Seeds because the 790 Coin seed cost is among the highest in the game. Eliminating that expense boosts your gold-per-day from 186.1 to 279.1, and Everlasting variants grow year-round regardless of season.
Sell to the Merchant Ship for double profit: The Merchant Ship pays roughly double the standard sell price. Timing your King Water Chestnut sales to coincide with the ship's visits can nearly double your income from each harvest.
Straightforward cash crop: Unlike crops that are valuable mainly for cooking recipes, King Water Chestnut has no known recipes. Its value is purely in selling the raw harvest. This makes it simple to manage: just plant, harvest, and sell without worrying about saving any for the kitchen.