Water Caltrop

Overview

Water Caltrop is a vegetable crop in Starsand Island, described in-game as "the fruit of the aquatic plant water caltrop, resembling a pair of horns, is known for its spleen-strengthening and energy-boosting effects." It is a high-value crop that unlocks at the Senior Farmer tier of the Farming profession. Water Caltrop grows during Spring and Summer, takes 5 days and 18 hours to mature, and produces 4 Water Caltrop per harvest.

With a gold-per-day return of approximately 136.3 g/day, Water Caltrop ranks among the most profitable crops in the Senior Farmer tier, sitting just behind River Lotus (136.7 g/day) and well ahead of most other crops in the game. Both Water Caltrop and River Lotus require Paddy Fields for planting, which means investing in Paddy Field infrastructure pays off significantly once you reach Senior Farmer.

Water Caltrop is also a valuable source of Vegetable Juice when processed through the Separator. A single Water Caltrop produces 24 Vegetable Juice, one of the highest yields of any crop. This makes surplus Water Caltrop extremely useful for stocking up on a cooking ingredient that appears in dozens of recipes.

Quick Stats

How to Obtain Seeds

Water Caltrop Seeds are sold by Graminova at the Happiness Seed Shop for 420 Coins per seed bag. You must reach the Senior Farmer tier before Water Caltrop Seeds appear in the shop inventory.

To unlock Senior Farmer, you need to complete each previous tier's certification trials (Novice, Apprentice, Intermediate, Junior) and then pass the Senior Farmer trial given by Graminova. This requires significant farming experience and completion of various farming milestones. Once you earn the Senior Farmer certification, Water Caltrop Seeds (along with other Senior-tier seeds like Rice, Mint, Aloe Vera, Mandrake, River Lotus, and Reishi Mushroom) become permanently available for purchase.

Seeds are not locked by season at the point of purchase. You can buy Water Caltrop Seeds during any season and stockpile them for the next Spring or Summer planting window. This is a smart strategy near the end of Winter or Autumn when you want to prepare for the upcoming growing season.

An alternative way to obtain Water Caltrop Seeds is through the Grinder. Loading 2 Water Caltrop into the Grinder will produce Water Caltrop Seeds, allowing you to recycle part of your harvest back into planting material. The Grinder unlocks at the Senior Farmer tier, so it becomes available at the same time as the crop itself. 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 Water Caltrop

Water Caltrop 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 Water Caltrop, select the seeds from your inventory and place them into an available Paddy Field plot.

Once planted, Water Caltrop takes 5 days and 18 hours to fully mature. Because Paddy Fields keep the soil permanently flooded, Water Caltrop does not require manual watering. The standing water counts as constant irrigation, which saves time and stamina compared to Farmland crops that need daily watering. This is one of the key advantages of Paddy Field crops.

Water Caltrop is a single-harvest crop. After you pick the 4 Water Caltrop, the plant is consumed and the Paddy Field plot becomes empty. You must replant from seed if you want to continue growing Water Caltrop in that spot. This is the same behavior as other Paddy Field crops like Rice and River Lotus.

Seasonal Availability

Water Caltrop grows in both Spring and Summer. 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 5.75 days (5 days 18 hours), you can complete up to 9 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 Summer. If you plant Water Caltrop with fewer than 6 days remaining in Summer, the crop may not finish growing before the season changes to Autumn. Any immature crops left in the ground when the season ends will not progress.

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, River Lotus, King Water Chestnut, 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 Water Caltrop because its relatively long growth cycle means you do not need to tend the plot daily. Simply plant, wait about 6 days, harvest, and replant. If you are building a large-scale farming operation, dedicating several Paddy Field plots to Water Caltrop is one of the most efficient uses of that space during Spring and Summer.

Sell Prices

Each Water Caltrop sells for 301 Coins. Since one seed (420 Coins) produces 4 Water Caltrop, a single harvest yields 1,204 Coins in revenue, for a net profit of 784 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 Water Caltrop revenue to around 602 Coins per unit. Timing your harvests to coincide with the ship's visits maximizes your earnings significantly.

Profitability Analysis

Water Caltrop is one of the top earners in the Senior Farmer tier. Its gold-per-day calculation works out to approximately 136.3 g/day, placing it just behind River Lotus (136.7 g/day) for the highest daily return among Senior crops. The table below compares Water Caltrop with other Senior Farmer tier crops.

Water Caltrop and River Lotus form a complementary pair for year-round Paddy Field farming. Water Caltrop covers Spring and Summer while River Lotus covers Autumn and Winter. By rotating between the two crops in your Paddy Fields, you can maintain top-tier income across all four seasons without any downtime.

Compared to Mint, which shares the same Spring/Summer window, Water Caltrop offers a slightly higher gold-per-day return (136.3 vs 130.7). However, Mint grows on standard Farmland rather than Paddy Fields, so the two crops do not compete for the same plot space. Growing both simultaneously is the optimal strategy if you have Paddy Fields and Farmland available.

For a full breakdown of all crop earnings, see the Crop Profitability Rankings page.

Processing Options

Water Caltrop can be processed at three different stations to produce useful materials. It has no known cooking recipes as a direct ingredient, but its processing outputs are valuable.

The standout processing option is the Separator. A single Water Caltrop produces 24 Vegetable Juice, which ranks among the highest yields of any crop (only Winter Melon at 28 per unit produces more). Vegetable Juice is one of the most commonly required cooking ingredients in the game, appearing in numerous recipes. If you have a surplus of Water Caltrop beyond what you want to sell, running them through the Separator is an extremely efficient way to build up a Vegetable Juice stockpile.

Pickled Water Caltrop is produced at the Pickling Jar, which unlocks at the Intermediate Farmer tier. The process requires 2 Water Caltrop and 2 Salt Bricks. Pickled Water Caltrop can be used as a gift or sold for additional income.

The Grinder converts 2 Water Caltrop back into Water Caltrop Seeds. Since the Grinder unlocks at Senior Farmer (the same tier as the crop), you can start recycling harvests into seeds right away. This helps reduce your ongoing seed costs, though at 2 crops per seed you sacrifice 602 Coins worth of sellable produce to save 420 Coins on seeds, so purchasing from the shop is generally more cost-effective unless you are short on Coins.

Gifting Preferences

Water Caltrop is a moderately popular gift among island residents and animals. Giving Water Caltrop to a character who loves it provides a significant boost to your friendship level. Below are the known preferences.

Since Graminova loves Water Caltrop and she is the Farming profession mentor, gifting her Water Caltrop 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 Water Caltrop Seeds

Like all crops in Starsand Island, Water Caltrop has an Everlasting variant. Everlasting Water Caltrop 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 Water Caltrop 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 Water Caltrop plant will yield an Everlasting Water Caltrop 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 Water Caltrop Seeds lets you maintain a permanent Water Caltrop field that produces vegetables every 5.75 days without any ongoing seed costs. Given the 420 Coin seed cost, Everlasting Seeds are especially valuable here since they eliminate a significant recurring expense.

Everlasting Seeds also ignore season restrictions, meaning your Everlasting Water Caltrop will continue to grow and produce harvests even during Autumn and Winter. This transforms Water Caltrop from a two-season crop into a year-round income source, further boosting its already excellent profitability.

Tips

• Pair with River Lotus for year-round Paddy Field income: Water Caltrop covers Spring and Summer while River Lotus covers Autumn and Winter. Rotating between these two crops in your Paddy Fields gives you top-tier earnings across all four seasons.

• Build extra Paddy Fields before Senior Farmer: Prepare Paddy Field plots in advance so you can plant Water Caltrop immediately upon unlocking Senior Farmer. More plots means more simultaneous harvests and higher total income.

• Use the Separator for Vegetable Juice: With 24 Vegetable Juice per Water Caltrop, this is one of the best crops for stocking up on this essential cooking ingredient. Even processing a few spare Water Caltrop each harvest cycle builds a substantial Vegetable Juice reserve.

• Time your last planting of Summer carefully: With a 5.75-day growth time, make sure you plant your final batch no later than day 22 of Summer to guarantee the harvest completes before Autumn begins.

• Gift Water Caltrop 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: Water Caltrop is a prime candidate for Everlasting Seeds because the 420 Coin seed cost is one of the highest in the game. Eliminating that expense turns every harvest into pure profit, 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 Water Caltrop sales to coincide with the ship's visits can nearly double your income from each harvest.