Producing Hydroponic Culinary Herbs

There is no doubt about it — ornamental flowering crops are still the bread and butter for many greenhouse operations across the country. However, there are emerging opportunities for greenhouses to produce edible crops.



The increased interest in locally produced food is giving greenhouse growers cause to reflect on the products they grow. Are there opportunities to produce food crops in your greenhouse?

Switching over to tomato, cucumber or pepper production can be a big change for any greenhouse. These crops have long production cycles and may not fit as easily into windows of opportunity between ornamental production cycles. However, culinary herbs are a relatively quick and can easily be grown in simple hydroponic systems (Figure 1).

Select Your Crops

The first question to answer in hydroponic culinary herb production is, “What should I grow?” Herbs vary widely in popularity. Basil is, by far, the most popular culinary herb and is the most widely grown. Other popular annual herbs include parsley, dill and cilantro. Some popular perennial herbs include rosemary, mint, thyme and oregano. While you may want to focus strictly on the most popular herbs or those used in the biggest quantities, you still may want to consider growing some of the minor herbs such as sage, marjoram and chervil in order to offer your customers a complete suite of culinary herbs.

If you are looking to culinary herbs to fill an open space in an already-established production schedule, it may be best to focus on annual herbs. These crops are easily propagated by seed, generally require less time from sowing to harvest, regenerate quickly following harvest and do not grow extensive root systems, which make them more amenable to different production systems.
Alternatively, if you are looking at starting a longer-term herb program, perennials should be considered. Perennial herbs are commonly propagated from stem-tip cuttings, take slightly longer to reach a harvestable stage, regenerate following harvest and have a larger root mass, which must be taken into consideration when selecting production systems.

Choose A Production System

There are many ways culinary herbs may be produced. “Living herbs” can be produced just like containerized ornamentals grown in the greenhouse. A plastic container filled with a commercial substrate works well for this purpose. Managing nutrition for “living herbs” grown in peat-based substrate is also similar to fertilization strategies used for containerized ornamentals.
Alternatively, a hydroponic production system is a good choice for producing fresh-cut culinary herbs.

There are many hydroponic systems that would be amenable for culinary herb production — too many to cover in this article. The two systems that should be considered first are the nutrient film technique (NFT) and water or flow culture.

The NFT system is a relatively simple recirculating hydroponic system (Figure 2). The main components are a nutrient solution tank and troughs or channels that plants are grown in. The size of the nutrient solution tank will depend on the number of troughs that will be irrigated.

From the tank, nutrient solution is pumped up and delivered to troughs at the rate of around ¼ gallon per minute. The troughs range in size, but for annual herb production, troughs measuring around 2 inches deep and 4 inches wide are common; wider and deeper troughs may be used for plants with larger root systems, such as perennial herbs.

The length of the trough can also vary in length from just a few feet to up to 30 feet long. Nutrient solution flows down the trough, which are on a 1 to 3 percent slope, creating a thin flow or film (hence the name) of solution bathing plant roots. Additionally, the top of the troughs are usually covered to block out sun and impede algae growth. After reaching the end of the trough, the water is then collected and drained back into the nutrient solution tank.

One advantage of this system is that the constantly circulating water will usually have adequate dissolved oxygen in the nutrient solution — a key factor for hydroponic production. However, one of the drawbacks of using the NFT system is that if a pump fails and nutrient solution ceases to be provided to plants, problems may not be far off.

Another hydroponic system that is useful for herb production is called raceway, raft or floating culture (Figure 3). This system basically consists of a pool of water, ranging from 6 to 12 inches deep that is filled with nutrient solution. The pool or raceway can be constructed with a 2-by-12-inch board and a vinyl liner. Smaller, commercially built units may also be purchased. Polystyrene boards 1 ½ to 2 inches thick are floated on top of the nutrient solution and plants are placed in holes so that the root system comes in contact with the nutrient solution.

One challenge with this system is that without the circulating water, dissolved oxygen levels can decrease to sub-optimal levels and require aeration to maintain oxygen levels. However, one of the biggest benefits of this system is that plants are growing in the nutrient solution and are not dependent on pumps to provide water. In the case of a power outage, the crop will be fine until power is restored.

What Next?

This article is by no means a comprehensive guide to hydroponic culinary herb production. However, hopefully you now have a better understanding of the process and can evaluate if there may be a place for culinary herb production in your business.

I think that there is a real opportunity for culinary herb products. For example, let’s take a look at the holiday season. Fall and early winter (i.e. Thanksgiving through the New Year) is a time when people are getting together to celebrate with family and friends or with businesses and coworkers. This is a time when restaurants are busy and looking for locally sourced culinary herbs.

Alternatively, gatherings hosted at homes have appetizers or dinners as focal points and cooks will be looking for high-quality fresh herbs at their grocery store.

If you are looking for an alternative to poinsettias to fill your greenhouse in the fall and early winter before bedding plant production starts, hydroponic culinary herbs may be a crop to consider.

Topics: , ,

Leave a Reply

One comment on “Producing Hydroponic Culinary Herbs

More From Vegetables...

March 26, 2015

10 Greenhouse Products For First-Rate Growing Environments

From coverings to fork-lifts, greenhouse suppliers offer a variety of products to make growing easier. Check out the slideshow to learn more about these, plus several other products that can offer you value, versatility and durability.

Read More
Rose rosette on Knockout rose, April 2012. Photo credit: Alan Windham, University of Tennessee

March 25, 2015

$58 Million In APHIS Farm Bill Funding Will Support Horticulture Priorities

Nearly $58 million as been allocated by the USDA's Animal and Plant Health Inspection Service (APHIS) to support the industry's Plant Pest and Disease Management and Disaster Prevention Program, under Farm Bill Section 10007. The program will support mitigation efforts for specialty crops, including providing research and other funding to address plant pest and disease priorities for the specialty crop industry, including floriculture and nursery crops.

Read More
AFE scholarship_Ryan Dickson

March 25, 2015

AFE Educational Grant And Scholarship Application Deadlines Approaching

Apply now for American Floral Endowment (AFE) scholarships or educational grants. Applications can be found online. For educational grants for 2015-2016, applications must be submitted no later than June 1. Scholarship applications are due May 1. AFE will award $40,000 in scholarships for 2015.

Read More
Latest Stories

November 24, 2014

Root Crops And Plug Trays: A Perfect Match

Growing a plant to maturity in plug trays might be foreign to ornamental growers, but with a little help from plug tray manufacturers and breeders, there is little to hold growers back in this root crop category.

Read More

November 14, 2014

First Vegetatively Propagated All-America Selections (A…

All-America Selections (AAS) honors two vegetatively propagated impatiens with AAS winner status.

Read More

October 8, 2014

Gotham Greens To Build Rooftop Farm In Chicago

Gotham Greens announced October 7 that it has partnered with Method Products, an eco-friendly cleaning product company - to build what they are calling the "world's largest rooftop farm" at Method's new manufacturing plant in the Pullman neighborhood, on Chicago's south side.

Read More

August 19, 2014

A Look Ahead At Food Safety For Commercial Greenhouse V…

If you grow food in your greenhouse that is sold for consumption, food safety regulations will affect you. Here is a recap of Debbie Hamrick’s (North Carolina Farm Bureau Federation) Cultivate'14 presentation on food safety for commercial greenhouse vegetable production.

Read More

July 22, 2014

Bright Farms Launches Crowdfunding Campaign To Build Ur…

Urban farming pioneer Bright Farms is attempting to crowdfund what it hopes will be the "world's most productive urban farm," in Washington, D.C.

Read More

July 18, 2014

Meeting The Demand For Edibles: Go Green Agriculture In…

Read about how Go Green Agriculture Inc. took its business from the classroom to commercial reality in one of four articles on how growers are appealing to the growing interest in edibles.

Read More

July 18, 2014

Meeting The Demand For Edibles: Peace Tree Farm

Interest and response to Peace Tree Farm’s annuals and foliage plants continues to increase, but herb and vegetable starter plants is where the company makes its money. Read about it in one of four articles on how growers are appealing to the growing interest in edibles.

Read More

July 18, 2014

Meeting The Demand For Edibles: High Meadows Farm

Grants brought opportunities for High Meadows Farm to start growing raspberries and tomatoes. Read about it in one of four articles on how growers are appealing to the growing interest in edibles.

Read More

July 18, 2014

Meeting The Demand For Edibles: Altman Plants

Read about Altman Plants' venture into greenhouse vegetable production in one of four articles on how growers are appealing to the growing interest in edibles.

Read More

July 15, 2014

Cultivate’14: Vegetable Production Tour Highlight…

Check out photos from Greenhouse Grower's visit to CropKing Inc.'s research greenhouses as part of he vegetable production tour at Cultivate'14.

Read More

July 8, 2014

Veterans Are Well-Suited For Grower Jobs, And AgVets Is…

AgVets is breaking ground this summer with the first of up to 30 hydroponic greenhouse operations located throughout the country to provide produce to lower- and middle-income consumers.

Read More

June 27, 2014

Growing Beyond New York, Gotham Greens Is Developing Pr…

Gotham Greens is considering the potential for partnering with growers for new ventures in cities across the U.S.

Read More

June 27, 2014

Gotham Greens Takes Locally Grown Produce To A Whole Ne…

Gotham Greens broke the boundaries of agriculture by building the country’s first commercial-scale rooftop greenhouse operation in Brooklyn, N.Y. Now it’s taking that vision further with two more locations and contracts to build in more cities.

Read More

June 25, 2014

New Trends, New Crops Offer New Possibilities For Edibl…

New small-space vegetables, container trends and flower/vegetable groupings contribute to a resurgence of interest in growing edibles.

Read More

April 11, 2014

Eight Standout Vegetables From Spring Trials [Slideshow…

Reflecting the consumers' passion for growing food, a number of breeders introduced attractive and flavorful vegetable varieties. Here are a few of my favorites.

Read More

April 10, 2014

Syngenta Opens Application Period For Grow More Vegetab…

The Syngenta Grow More Vegetables Seed Grant Program supports schools and community organizations interested in establishing or enhancing garden programs. Applications are now being accepted for 2014.

Read More

April 10, 2014

Managing Organic Food Waste In Your Business

The single largest component of the nation’s waste stream by weight is food waste. Here is what you need to consider before implementing a food waste collection system at your business.

Read More

April 10, 2014

Vegetalis Is Working To Make Growing Vegetables Easy Fo…

For the past four years, Vegetalis has presented container vegetable crops at Spring Trials, and while growers and retailers have been excited about Vegetalis’ offerings, there haven’t been enough sales. So this year, the company is working on a few new marketing concepts to bring Vegetalis’ considerable number of container veggies to retailers nationwide.

Read More