Greenhouse
The Greenhouse is the ultimate farming structure in Starsand Island, allowing crops to grow year-round regardless of the current season. It is unlocked at the Expert Farmer certification tier, the highest level in the Farmer profession, and costs 55,000 coins from Graminova's Happiness Seed Shop. The Greenhouse is the endgame farming investment, removing seasonal restrictions entirely and enabling maximum crop flexibility.
How to Unlock
The Greenhouse Building Manual is sold by Graminova at the Happiness Seed Shop for 55,000 coins. It requires Expert Farmer certification, which is the fifth and final tier of the Farmer profession. To reach Expert Farmer, you must complete all of Graminova's certification quests through the previous four tiers.

Farming Profession Tiers
The Farmer profession has five certification levels, each unlocking new equipment, seeds, and abilities. You must complete each tier's quests in order.
Tier | Key Unlocks |
|---|---|
Apprentice Farmer | Basic seeds, manual planting and watering, Watering Can |
Junior Farmer | Planting Boxes for indoor growing, additional crop types |
Intermediate Farmer | Sprinkler I (automatic watering), tree saplings, expanded seed selection |
Senior Farmer | Grinder (convert crops to seeds), Eternal Blessings skill, flowers, Sprinkler II |
Expert Farmer | Greenhouse Building Manual (55,000 coins), Sprinkler III (25,000), Starsand Grinder (55,000), Fertilizer Box V (4,000), Hydraulic Hoe (10,000) |
Reaching Expert Farmer takes significant time and effort. You must progress through the entire farming questline, growing crops, harvesting fruit from trees, raising Gmax crops, and completing all of Graminova's trial tasks at each tier.
How the Greenhouse Works
Once you purchase the Greenhouse Building Manual and build the structure, any crops planted inside grow independently of the outdoor season. This means:
Spring-only crops (like Strawberries) can be grown during Winter inside the Greenhouse.
Summer-only crops continue producing through Autumn and Winter.
You can grow all crop types simultaneously regardless of what month it is.
Seasonal restrictions still apply to outdoor plots. Only the Greenhouse interior bypasses them.
Crops inside the Greenhouse follow the same growth timers as outdoor crops. The only difference is the removal of seasonal availability. Watering, fertilizing, and harvesting work exactly the same way inside the Greenhouse as they do outside.
Expanding the Greenhouse
The Greenhouse can be expanded in length during initial placement. To make it wider, use the Copy feature in the building interface. This duplicates the Greenhouse structure and lets you place copies side by side, effectively creating a wider growing area. This is not immediately obvious from the build menu, and many players initially think the Greenhouse is limited to a single narrow strip.
You can place Sprinklers inside the Greenhouse to automate watering, just like on outdoor farmland. A Sprinkler II or Sprinkler III inside the Greenhouse covers the planted area and removes the need for manual watering entirely.
Greenhouse vs. Planting Boxes
The Planting Box is an earlier alternative for indoor growing, unlocked at the Junior Farmer tier. It allows you to grow specific crops inside your house. Here is how the two compare.
Feature | Greenhouse | Planting Box |
|---|---|---|
Unlock Tier | Expert Farmer | Junior Farmer |
Cost | 55,000 coins (Building Manual) | Much cheaper (early-game blueprint) |
Season Independence | Full: all crops, all seasons | Partial: specific crops only (mushrooms, garlic, etc.) |
Sprinkler Support | Yes, place Sprinklers inside | No automatic watering |
Scalability | Large area, expandable via Copy feature | Small individual boxes |
Location | Separate outdoor structure | Inside your home |
Planting Boxes are a useful stepping stone in the early and mid game. They let you grow mushrooms, garlic, and other specific crops indoors before you have access to the Greenhouse. Once you reach Expert Farmer and can afford the 55,000-coin investment, the Greenhouse completely supersedes Planting Boxes for season-independent growing.
Expert Farmer Blueprints
The Greenhouse is just one of several blueprints available at the Expert Farmer tier. Here is the full list of items you can purchase from Graminova once you reach Expert certification.
Blueprint | Price |
|---|---|
Greenhouse Building Manual | 55,000 coins |
Starsand Grinder Blueprint | 55,000 coins |
Sprinkler III Blueprint | 25,000 coins |
Hydraulic Hoe Blueprint | 10,000 coins |
Fertilizer Box V Blueprint | 4,000 coins |
The Greenhouse and Starsand Grinder are the most expensive items at 55,000 coins each. Budget accordingly; reaching Expert Farmer without enough coins to buy the blueprints means you will need additional farming income before you can take advantage of the tier.
Optimal Greenhouse Crops
The Greenhouse is most valuable for crops that are restricted to a single season outdoors. Growing them year-round inside the Greenhouse maximizes your return on the investment.
Seed | Details |
|---|---|
Off-season cash crops | Grow high-value crops that only appear in one season. Selling them during their off-season when outdoor supply is zero maximizes profit. |
Everlasting crops | If you have unlocked the Eternal Blessings skill at Senior Farmer, plant Everlasting Seeds in the Greenhouse. These crops never die after harvest and keep producing indefinitely, making the Greenhouse a permanent income source. |
Cross-breeding projects | Use the Greenhouse for cross-breeding flower experiments that require specific seasonal flowers to be growing simultaneously. |
Rare or slow-growing crops | Crops with long growth cycles benefit from the Greenhouse because you never lose progress to a season change. |
Tips
Start saving coins before you reach Expert Farmer. The 55,000-coin Greenhouse Manual is a steep purchase, and you will want other Expert blueprints too.
Place Sprinkler IIs or IIIs inside the Greenhouse immediately. Without them, you will spend too much time manually watering indoor crops.
Use the Copy feature to expand your Greenhouse. A single structure is narrow; copying and placing side by side gives you a much larger growing area.
The Greenhouse does not change crop growth speed. It only removes seasonal restrictions. Fertilizer and high-tier seeds still matter for fast harvests.
Combine the Greenhouse with the Starsand Grinder (also Expert Farmer, 55,000 coins) to create a self-sustaining loop: harvest crops, grind some into seeds, replant, and sell the rest.
Planting Boxes remain useful even after building a Greenhouse. Keep a few in your house for convenience crops like mushrooms that you use frequently in cooking.