How to Estimate the Costs and Production of a Small Greenhouse

My wife and I have an empty lot behind our rental property that measures about 1,800 square feet. We need some of it for parking, so we are left with about 1,200 square feet. The property came with an old greenhouse. While it isnt much to look at, it was free. Recently, my wife and I were wondering how much we could grow if we upgraded our growing techniques.

I happen to work for Bright Agrotech, and so I have access to detailed production estimates. I chose a greenhouse that measures 720 square feet, which will leave some room for our composting and some rooting crops we like to plant in covered rows.

The team at Bright Agrotech has spent the last 6 years testing vertical growing equipment. Our numbers can be helpful when planning a small growing operation. I wanted to take a look at what is possible, and share my results with you. The low cost of this system, and the high production numbers are opening up a new world of opportunities for small business owners and first time growers.

This is a greenhouse that measures 720 square feet, or about the size of a one bedroom apartment.


$6,266.00 Conley Cold Frame Greenhouse, with heating unit and weedblock ground cover included (20 by 36)
$8,525.00 Vertical Growing Towers (x150)
$330.86 8 custom wood racks for supporting the growing towers
$113.62 Plumbing equipment to the towers
$1,098.24 Water tank, pump, and irrigation equipment to the towers
$16,333.72 Total price
$495 Shipping

This style of greenhouse is called a cold frame, which is basically rolled metal supports with rigid end walls. The greenhouse is covered with a double layer of heavy duty plastic, which is inflated with a small air blower. This adds an extra layer of insulation to the greenhouse. With a heating unit (included), it is possible to grow through colder seasons.

This design also includes 150 ZipGrow towers. These towers were designed to take advantage of the vertical growing space in the greenhouse. Vertical growing can double or triple production yields compared to horizontal growing methods.Our old greenhouse

This greenhouse is able to grow up to 600 pounds of herbs and veggies every 5 weeks. Here is a look at what is possible with this greenhouse:

With good branding and labeling, locally grown greens and salad mix are worth around $3.20 /lb wholesale pricing. We assume that 90% of the greenhouse will be used to grow things like lettuce, kale, collard greens, arugula, and others. We estimate that we can grow 540 pounds a month, for a cash crop of $1,728.

Basil, mint, and other herbs are valued at $2/ounce. Since there is a limited market for these crops, we estimate that 10% of the greenhouse will go towards these crops. This is 60 pounds of herbs valued at $1,920.

The harvest can be achieved monthly from April through October with minimal labor costs and no supplemental lighting. My wife and I plan on spending an hour a day with our kids, mostly tending the crops. On weekends we might plan on half a day for harvesting and seeding new crops. We are also looking at things like a washing machine salad spinner and a DIY walk in cooler. This piece of equipment will let us turn our storage shed into a walk in cooler, for keeping our crops cool and fresh for delivery.Here is a look at the new production style greenhouse.

As with most small businesses, the main difficulty is finding a market and selling the produce. I spent some time wondering how much you can earn selling wholesale produce and herbs.I have published an eGuide that discusses how much you can earn selling vegetables. In a perfect market, my wife and could could work this greenhouse part time on nights and weekends, and generate $39,480 in produce per year.

Obviously, basil and herbs are worth more, and if you can find a customer to buy them it will be worthwhile to dedicate more of the greenhouse to these crops. Tomatoes are always in demand, and it might be worthwhile to dedicate a portion of the greenhouse to these or other specialty crops. There will be seasonal adjustments, since some herbs don’t grow well in warm weather. I live in a small town, and I am planning on speaking with the produce manager at the local grocery store (we live two blocks from the grocery store).

If you are interested in selling locally grown food to your market, I would encourage you to check out the market guide I wrote, titled Selling Your Produce; The New Farmers Guide to Choosing a Market.

If you are seriously considering a business of this kind, you will need a cost and expense projection. The expenses for this type of business include:

  1. Equipment purchaseMother's Little Helper
  2. Land
  3. Seeds
  4. Water
  5. Light
  6. Cooler
  7. Delivery
  8. Utilities
  9. Nutrients
  10. Labor

The ease and flexibility of this kind of greenhouse is helping power a new economy in local food. The demand for local food has broken down the usual barriers that prevent small growers from getting onto the shelf. For example, Bayberry Fresh Farms is a small farm in Fort Collins, Colorado, that is able to bring their crops to three regional Whole Foods grocery stores, as well as a handful of restaurants and private accounts. The farms owner echoes many others who say that it has never been easier to find a market for locally grown food.

And thats exciting. If you have wondered about the ROI of a small greenhouse, this should give you some basic guidelines.You can see the costs and materials that went into this greenhouse design at the link below.

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