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Systems and Tech Thoughts

2020 Summer of Sprouts

October 24, 2020

Last summer I grew sprouts. I’ve always enjoyed gardening but am currently living in an apartment with very little light exposure. Due to the low light constraints, sprouts were one of the few things I could grow outdoors without supplemental light. This article details my sprout yields and total financial investments and overall season outcomes. My goal for the summer was to harvest on a regular cadence and to break even on my sprout investment! This blog post analyzes the numbers to determine if I actually broke even (spoiler: I didn’t)!

season total

Why Sprouts?

I chose sprouts for a couple of reasons:

  • Low light requirements: Sprouts do not need direct sunlight which is essential for my setup.
  • Low nutrient requirements: Since sprouts are harvested before the first true leaves (Cotyledons) the sprout seeds contain most of the nutrients necessary to grow them. This means that I shouldn’t have to supplement nutrients to the soil.
  • Low startup costs
  • Short harvest cycle: Sprouts can go from seed to ready to eat in 7-10 days.
  • Edible: I enjoy eating vegetables and I wanted to grow something that I would enjoy eating and wouldn’t go to waste.

The Setup

I set everything up on my porch. The porch is west facing and receives no direct sunlight.

baby_sprouts

The setup included:

  • Metal shelf from amazon
  • Growing trays with clear plastic lids
  • Soil & seeds & water!

Assumptions

I considered the growing season 12 weeks from June through August. I also assumed that an ounce of organic spouts sells for $1. At the beginning of the summer I looked at whole foods and saw 4 ounce bag of sprouts costs ~$4.00.

Inputs

inputs

It is worth noting that the seed trays had a ~3-4x markup. I’m guessing this was from the increased demand due to coronavirus and lockdown. The biggest contributor to costs, for each harvest, was seeds:

seed cost

The first batch of seeds I bought cost $0.12 per gram, and the second batch cost $0.06. The majority of harvests used 20 grams of seeds, either $2.40 or $1.20 depending on the seed batch.

seeds per planting

Twenty grams seemed to be the sweet spot. One thing that was interesting was that harvests varied wildly; sometimes 20 grams of seeds yielded 5 ounces of sprouts, other times < 2 ounces. I plan on digging into this next summer and conducting some controlled experiments, using temp, light and water and nutrients.

Cadence & Yields

I harvested 8 out of 12 weeks, which was 66% of the target. The following image shows each individual harvest and its yield in ounces:

harvest yields

Some weeks didn’t yield enough to cover the cost of seeds:

profit for each harvest

I harvested each batch, washed it and weighed it using a kitchen scale. I tried to dry the sprouts off after washing to minimize the effect of the water weight.

small harvest

I mainly ate the sprouts on sandwiches and salads.

tomato sprout sandwich

All Together

I had a lot of fun this summer. The goals I set were low pressure but fun enough to give me something to work towards. I found it really helpful to keep track of costs and yields. I’m not using actual accounting principles, but next year I won’t have the shelf and trays as part of the season expenses. I also plan on sticking to planned weekly plantings next year, in addition to running some experiments to maximize yields.

season total

Below shows the current state, after the final harvest:

season over

Thank you for reading, and happy growing!

baby_sprouts_evening


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