Speed-Gro vs Fertilizer: Which Is Worth Buying?

By Ali Ahmad · Updated October 9, 2026 · Verified for Stardew Valley 1.6.15

Every number below is profit per tile for one season, planted on day 1 and replanted the same day after each harvest, at farming level 6, sold raw, no professions. The cost of one bag per tile is already taken off. One bag is enough for the season: the wiki's Fertilizer page says fertilizer "remains in the soil all season", so you don't pay again when you replant. The best option for each crop is highlighted.

Why Speed-Gro so often loses

Speed-Gro cuts growing time by at least 10%, but a season is 28 days and harvests come in whole days. Cauliflower takes 12 days, or 10 with Speed-Gro. Planted on day 1 you harvest on days 11 and 21 instead of 13 and 25, and a third harvest would land on day 31, after the season ends. Two harvests either way, so you spent 100g for nothing: 232g a tile without it, 132g with it.

It only pays when the saved days add up to a whole extra harvest. Potato and Kale go from 4 to 5 harvests, and Bok Choy from 6 to 9. Even then the gain is small, because each extra harvest of a cheap crop is worth little. Potato still ends up lower with Speed-Gro (199g against 239g).

For regrowing crops like Blueberry, Speed-Gro only shortens the first growth, not the days between harvests. On Blueberry that still adds one harvest and pays (605g against 548g). On Cranberries it adds nothing, and nothing beats planting them bare.

Deluxe Speed-Gro: the one worth buying

Deluxe Speed-Gro cuts growing time by at least 25%. Cauliflower drops to 9 days and is ready on days 10, 19 and 28. That is enough to squeeze a third harvest of a 12 or 13 day crop into a 28-day season. That is where the big jumps in the table come from: Starfruit goes from 882g to 1,243g a tile, and Pumpkin from 518g to 697g.

Buy it at the Oasis for 80g if you can. Pierre sells it for 150g, which is still worth it on Starfruit and Pumpkin but eats most of the gain on cheaper crops. To get the third harvest you have to plant on day 1, so buy the bags at the end of the season before.

Basic and Quality Fertilizer

Quality fertilizer raises the chance of a silver or gold crop, but only on the first item of each harvest. For a 80g Potato, a better chance at silver isn't worth 100g a tile. It only pays on expensive crops: at level 6, Quality Fertilizer takes Starfruit from 882g to 1,017g. At farming level 0 it doesn't even pay there (660g against 715g), because your quality chances are still low.

Early in the game the gap is wider. A level 0 Potato makes 203g a tile bare and only 74g with Quality Fertilizer. Spend that gold on more seeds instead.

What about Deluxe Fertilizer and Hyper Speed-Gro?

Neither is sold for gold. You craft them after buying the recipes in Qi's Walnut Room on Ginger Island, so the table leaves them out. If you already have Deluxe Fertilizer, use it on your most valuable crop. Without counting its cost, it takes Starfruit to 1,519g a tile and Cranberries to 754g.

Which days you harvest

The table above is easier to trust when you can see the calendar behind it. This one lists the harvest days for a crop planted on day 1 of its season, with nothing, Speed-Gro and Deluxe Speed-Gro. A season ends on day 28, so a harvest on day 29 or later never happens.

Highlighted cells have more harvests than the unfertilized crop. Regrowing crops (Blueberry, Cranberries) harvest again every few days after the first.

Read the Starfruit row. Without help it is ready on day 14 and again on day 27, two harvests. Speed-Gro moves them to days 12 and 23, still two, and the next would be day 34. Deluxe Speed-Gro gives days 10, 19 and 28. The third harvest lands on the very last day of the season, which is why a crop that looks fast enough on paper can still miss it by one day. Check the last number in the Deluxe column before you buy: if it is 28, every day of delay costs you the harvest.

The same arithmetic explains the Potato row. Potato grows in 6 days, so it is a short-cycle crop where one day saved is a lot: Deluxe Speed-Gro turns four harvests into six. Speed-Gro alone gets you a fifth harvest on day 26, but one extra potato harvest is worth less than the 100g bag, which is why the profit table shows it losing.

Planting later than day 1

Most players don't plant everything on the first morning. Here is the same comparison for a planting on day 8 and on day 15 of the season, with the best option for each crop highlighted. Profit is per tile after paying for the bag, at farming level 6.

On day 8 Deluxe Speed-Gro still wins on every crop in the table, because with 21 days left it can still add a second harvest. On day 15 there are only 14 days left, no fertilizer adds a harvest to these crops, and the bag is pure cost. By then the best choice for all of them is to plant bare. If you reach the middle of a season with gold to spend, put it into seeds or machines, not into the bag.

Making your own

You don't have to buy speed fertilizer. Both are crafted, and one craft makes five bags.

• Speed-Gro (Farming level 3): 5 Moss, 1 Pine Tar makes 5 bags.
• Deluxe Speed-Gro (Farming level 8): 5 Bone Fragment, 1 Oak Resin makes 5 bags.

Moss, Pine Tar, Bone Fragments and Oak Resin are gathered or made, not sold, so there is no shop price to compare. What matters is the number of bags. A greenhouse of 116 tiles needs 116 bags per planting: 24 crafts, or 24 Oak Resin. Oak Resin comes from Oak Tree tappers, so a few tappers running all season cover it. Crafting Deluxe Speed-Gro in bulk before the season starts is how you reach the day-1 planting that the table assumes. The Crafting Calculator adds up the materials for any number of crafts.

Common mistakes

• Buying one bag per seed packet instead of one per tile. One bag covers a tile for the whole season, however many times you replant it.
• Using Speed-Gro on a regrowing crop for the regrow time. It shortens the first growth only. A Blueberry still gives berries every 4 days.
• Planting on day 2 for a three-harvest plan. The Starfruit schedule above ends on day 28 exactly. One day late and you lose the third harvest and the whole reason for the bag.
• Fertilizing every tile. Put it on the few tiles of your most valuable crop first. Starfruit and Pumpkin gain the most per bag, Potato and Kale gain the least.
• Counting Quality Fertilizer as a speed tool. It does nothing for timing. Judge it only on the chance of better quality.

Quick rules

• Planting a 12 or 13 day crop on day 1? Use Deluxe Speed-Gro.
• Regrowing crop? Speed-Gro only if it adds a harvest. Check with the Crop Profit Calculator.
• Cheap crop under 100g? Skip fertilizer and plant more tiles.
• Starfruit at farming level 6 or higher? Quality Fertilizer pays for itself.
• Planting mid-season? Use What to Plant Today, which counts the days you have left.

Work it out for your farm

• Crop Profit CalculatorProfit for every crop from today until the season ends, with your fertilizer, professions and sell method.
• What to Plant TodayTell it the day, your gold, tiles and machines; get one crop, why it wins, and a shopping list.

Where these numbers come from

Every number on this page is calculated by the same engine as our calculators, from game data taken from the Stardew Valley Wiki and cross-checked between at least two of its pages (last checked 2026-10-09). See the methodology, and tell us if something looks wrong in your game.

More guides

All tools and guides on this topic: Crops and Farming.

• How Many Kegs Do I Need?Kegs per plant for Hops, Ancient Fruit, Starfruit and more, so no fruit waits in a chest.
• Are Pigs Worth It?How fast a 16,000g pig pays for itself, and when Truffle Oil beats selling truffles.
• Best Fish for Fish PondsThe ponds that earn the most gold a day, raw or as Aged Roe and Caviar.
• Are Casks Worth It?Gold per cask per day for wine, cheese and ale, and what a full cellar costs.