Is Gardening Cheaper Than Groceries? Eggplant ROI

One thing I always wondered before starting my own indoor garden was whether growing your own food would be cheaper than buying groceries.

Anyone whose shopped for wood and compost at the store will know that building a well-fertilized garden bed can easily cost hundreds of dollars upfront.

And if growing outdoors is already an investment.. would indoor gardening be even more of a money pit?

It seems like most people wonder the same, because it’s a question I get a lot!

Now that I’ve been growing vegetables inside my apartment for several years, I have a good idea of the costs involved.

So I wanted to start tracking the economics of indoor gardening and today I’m looking specifically at the value of growing eggplants indoors.

Read more: How to Start an Indoor Garden

Do Indoor Gardens Save You Money?

This post is a continuation of my series on Indoor Gardening vs Groceries.

You can read my initial post here, which covers how to measure the value of a indoor garden, calculates the return on an indoor herb garden and compares which Aerogarden gives you the most bang for your buck.

For years, indoor gardening was just a hobby.

I found the process fun, and I especially liked growing ‘exotic’ vegetables.

In some cases, I grew things that were so foreign to me, I didn’t know what to do with them that I kept them on the counter until they rotted… and then threw them out lol.

RIP Chinese 5 color hot peppers 💀

I typically grow eggplants in these floor gardens, but any large indoor garden would work!

Garden vs Groceries

But now that I actually eat my produce, I started wondering how much I’ve been saving vs the grocery store.

So today we’ll borrow a finance concept and apply it to gardening: return on investment or ROI.

As an excel junkie, I find that looking at my hobby from a return, cost and investment perspective gives me a good frame of mind for how to maximize space in my apartment (in nyc, real estate is precious $$$!)

Calculating the ‘return’ for various vegetable categories also helps me get a sense of what’s ‘worth it’ to grow at home compared to just buying at the grocery store.

And it helps me refine what seeds I buy and what garden space I allocate.

Ultimately, I’m trying to grow as much healthy, pesticide-free food as possible for the lowest reasonable cost!

Growing Hydroponic Eggplants Indoors

Eggplants are one of my favorite things to grow.

It’s partly a matter of pride – when I was first started to grow larger vegetables, eggplants gave me a lot of trouble so whenever I see one in my gardens now I feel a lot of satisfaction.

Eggplants are also so unique.

There are hundreds of fun eggplant varieties that you’d never come across IRL unless you grow them yourself.

I love these fun purple pumpkin ones, these pretty stripped globes and these dark Japanese types.

I get another surge of satisfaction knowing that my homegrown eggplants literally aren’t for sale at any conventional grocery store.

just some of the eggplants i’ve grown in my indoor gardens

And overall, the eggplant growing process is very satisfying, from start to finish.

Eggplant flowers are delicate and pretty – more so than any other vegetable flower. Although eggplants can be hard to get going initially, once they produce, eggplants produce.

I’m overflowing in eggplants these days.

And eggplant plants are long lived – unlike tomato plants, an eggplant can keep churning out eggplants month after month.

My current indoor garden has 5 eggplants all over a year old. They look like mini tree shrubs at this point!

But are eggplants worth the time investment?

I love growing Asian eggplants.

They have thinner skins and less seeds than American eggplants, so they taste much sweeter and better in my opinion!

I also love growing eggplants in fun colors, like white, orange, green and deep purple black, as well as eggplants in unique shapes.

Here are some fun eggplant varieties I’d recommend:

1. container eggplant
2. Thai eggplant
3. Japanese pickling eggplant
4. Japanese round eggplant
5. Chinese string eggplant
6. striped Italian eggplant
7. Rosa bianca eggplant
8. Turkish orange eggplant

You can grow all different types of eggplants in different indoor garden setups.

And because eggplants need quite a bit of space, I’d recommend growing them in large hydroponic gardens:

1. Lettuce Grow Tower
2. Letpot Max
3. Aerogarden Farm
4. Aerogarden Bounty Elite

 

 

Is It Economical to Grow Vegetables Indoors?

To calculate if eggplants are ‘worth it’, we can use the concept of ROI:

ROI (return on investment)

ROI = (Harvest value – Costs) / Cost

Harvest Value

At my local grocery store, organic Asian eggplants cost $3.99/lb.

I’m growing two varieties of eggplants in my Aerogarden Farm: this long skinny Chinese eggplant and this medium Japanese type.

Eggplants start producing 60 – 70 days in, or around 2.5 months in. Once they get going, they’re quite heavy producers and continue to push out new eggplants every 2.5 weeks or so.

harvesting Asian eggplants that I grew inside my apartment

Conservatively, each month I’m able to harvest 3 Chinese eggplants weighing ~152 grams each, and 6 Japanese eggplants weighing ~62 grams each.

In total, that’s about 828 grams of eggplant a month, or 1.83 pounds.

I’ll estimate that my first full harvest occurs in month 4 and continues consistently through the end of the year.

In the first year, I can grow $107.64 of Asian eggplants.

Eggplant Growing Costs

A pack of heirloom eggplant seeds costs $3.99 a pack.

I purchased two packs of different Asian eggplant varieties. I planted just 5 seeds in my indoor garden, so the individual seed cost is pretty negligible.

Other supplies for indoor gardening include the seed baskets, sticker labels, humidity domes and sponges.

I re-use all of these from planting to planting except for sponges. Hydroponic sponges cost 5 cents each, or $0.25 to grow 5 eggplants.

In total, supplies cost me $8.23

Electricity Cost

The main cost associated with growing vegetables indoors is electricity.

The Aerogarden Farm 24 uses 126 watts of power and costs $8.98 to run each month. I used a Farm 12 to grow eggplants, so the electric cost for growing eggplants is half this, or $4.49.

(You can find an in-depth breakdown of Aerogarden electricity costs here)

12 months of electricity costs for the Harvest total $53.88.

Eggplant Garden ROI in Year 1

Growing eggplants in an Aerogarden Farm is just slightly profitable in the first year, with a 5.81% ROI!

It’s a good thing I get a lot of joy out of growing eggplants, because they’re essentially a breakeven crop in the first year due to the heavy cost of powering the Aerogarden Farm.

Let’s look at year 2.

I’m now in my second year of growing the same eggplants and they’re still as productive as ever.

Without the cost of supplies, the ongoing ROI of growing eggplants is just electricity.

But in year 2, we get a full 12 months of production, for a harvest value of $87.62.

Eggplant Garden ROI in Year 2

Year 2’s eggplant ROI is 62.6%!

That’s a BIG difference.

How to Make Gardening Cheaper Than Groceries

Growing eggplants in an Aerogarden Farm is much more profitable if you keep your existing plants running.

I’m glad I ran the math because I usually pull my plants out around the holidays, even if they’re still going strong.

Guess I shouldn’t always give into the urge to plant new things, when the value is really in year 2+!

Clearly, growing eggplants becomes more profitable with time, once the startup costs no longer factor into the equation.

It would also be cheaper to grow the eggplants in other hydroponic machines.

Smaller systems like the Letpot Max or Aerogarden Bounty use less powerful LEDs and cost less in electricity.

The Lettuce Grow tower grows up to 36 plants with one set of lights, so it’s also more economical.

Overall, despite the low to medium ROI of growing eggplants, as long as I grow hard-to-buy varieties I still feel like I’m getting my money’s worth :)

Follow me on

Youtube | Tiktok | Instagram | Substack