zipgrow-tower-dwarf-basil hydroponic basil

Dwarf basil in the first ZipGrow experimental greenhouse. Dwarf basil has smaller leaves and is bushier than most varieties.

Basil is a well-loved crop in almost every community.

The woody herb can be sweet, savory, or peppery, and it smells amazing. Basil has been used some way in almost every place in the world and has collected its own interesting history throughout the ages. (For a century or two, basil was thought to spawn scorpions.)

Basil belongs to the mint family (Lamiaceae), along with rosemary, oregano, thyme, and several other popular herbs.

Our favorite basil varieties are the classic sweet basil (Ocimum basilicum), Genovese basil, Thai basil, and dwarf basil. Sweet basil is a favorite among the Upstart Farmers.

Herbs are much more profitable than leafy greens, and can be a fantastic crop line for market growers. The pricing you receive will vary depending on your market. For example, Direct to Consumer markets like a CSA can often see prices as high as $2 or $3 an ounce, while wholesale markets like restaurants may land in the $1 to $1.50 an ounce range.

A recent price check at Target revealed that a 3/4 ounce clamshell package was retailing for $2.00, which comes out to $2.66 an ounce at the point of sale. A general rule of thumb is that wholesale pricing will be 40% to 50% of retail price.

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Ideal conditions for hydroponic basil

  • EC: 1.6–2.2
  • pH range: 5.6–6.6
  • Temperature: 65–95ºF

If mint scores a 1 in difficulty (it’s quite easy to grow), then woody herbs like basil are at the other end of the scale. Although basil isn’t needy in terms of water and pH, it does require pruning (see below) to achieve full yields and grows best in high temperatures which can be tough to match with other crops. When you can achieve ideal conditions, you’ll be amazed at the growth you can get from your basil crops. 

Matt Marsh is a basil farmer in North Carolina. Over the last year, Matt has focused on growing high-quality basil for his community above other crops and has several tips for new basil growers.

matt-marshquotation-39628_12801. Control humidity: The shape of basil leaves tend to catch water and hold it, so controlling condensation is very important. High humidity (above 70% for extended periods) has been problematic for us. We try to keep our humidity between 40–60% in the greenhouse. I haven’t seen any issues with running a lower humidity throughout the day but the basil transpires heavily in the dark periods. We haven’t seen low humidity for longer than 12–14 hours at a time.
 
*Good air flow but not a lot of “wind” on the plants. Basil is very sensitive. 
 
2. Light: Have a supplemental lighting option! We are currently fighting to fill orders because this winter has been much lower in light. Our basil grows decently with 10–12 hours of light but that is on the low end of weight per tower at a 5-week cycle. Supplementing light is almost a guarantee. We didn’t supplement light for the first year and got away with it because our demand wasn’t consistent. Now that everyone looks to us for basil, we have had to do “harvesting gymnastics” to keep everyone happy. 
 
3. Diligently manicure: We have always had random dying leaves (damaged, blocked from light, etc.) on the plants. We have learned to go through and pull as many off as we see because they have always affected the leaves around them in some negative manner. Some stick to the other leaves and damage them, others become a sponge and drip onto the other leaves, and others grow fungus. In short, clean around the plants well.
 
4. Prune: We have used harvest time as a way to prune plants that are end- or top-heavy. If the growth on the end of the stem is too heavy, it will split from the main root base and become bitter. If the stem/root is damaged we harvest immediately or throw it out.
 
We have eliminated all of our bitter basil by:
  • harvesting before bolting to flower
  • throwing out any old/tough growth
  • removing broken stems
quotation-39627_1280* Do not pinch. Invest in sharp sheers! You will damage or pull off a whole stem more often than you think!

Harvesting basil—how to cue apical growth

tj- hydroponic basil

Basil grows at Fable: From Farm to Table

Basil has been bred to be a single-stemmed plant growing upward. For most growers, a bushier plant is better. A pruned plant looks better, yields more, and can be easier to transport depending on your growing method.

Upward growth is called apical growth. To change the way that basil grows, growers can trigger a secondary type of growth that moves outward and up instead of straight up. This is called lateral growth.

A young basil plant (say 5–10 inches tall), has buds on the side of the stem that haven’t grown out yet. Those are the lateral buds; they’re the back-ups that will only grow if the main stalk gets badly damaged or removed.

This means that if growers clip the stem right above those lateral buds (a half inch or so), the buds will be triggered to grow out. By pruning basil this way, growers can increase the production of that branch and control the shape of the plant.

basil-cut-here hydroponic basil

When you go to harvest your basil for the first time, you’ll probably notice multiple pairs of lateral buds on the plant. Cut the plant above the second pair of buds. Matt explains why:

“We cut down to the second ‘Y’ in most cases. Any leaves above that split on the stem will be harvested. I used to cut down to the first ‘Y’ but it made the growth so tight that I had issues with moisture being held inside within the collection of leaves. So, moving out the second has fanned out the growth enough that it doesn’t stop airflow, light penetration, etc…”

If you prune a basil plant correctly, then you’ll see an increase in yield each time you harvest for the first three harvests (around weeks 5, 8, and 11).

local-greens-harvesting- hydroponic basil

Post-harvest care of basil

Several times now, we’ve had a conversation that goes like this:

“I brought a crate of basil cuttings to the chef at the restaurant I service. The next day, I got a call from him saying that the basil had gone bad! That’s impossible… I had just harvested it.”

Every time something like this happens, we ask, “did he put it in a cooler?” and always, the answer is yes. Usually, coolers are kept at 40–45º degrees, but basil doesn’t have the cellular machinery to deal with those temperatures. A few warm-weather crops respond to cold temperatures with rapid decay.

To extend the shelf life of basil, store it above 55º F (preferably at a temperature of 60º). At this temperature, it can attain a shelf life of 12 days. Instead of cooling the basil, keep it in a higher-temperature cooler, or on a counter in a cool room. For home consumers, a jar of water on a counter works great.

If growers package basil in bags or cartons that reduce moisture loss (plastic with little or no air exchange), be sure to keep storage temperatures steady to avoid condensation. Matt has had success with vented bags:

“We use vented bags and keep the basil out of sunlight at all costs! Our restaurants keep the bags in dry storage of some sort and most just hang the bags in the kitchen away from heat and certainly not in the cooler! If the restaurant has a wine cooler it is usually kept around 60–65ºF and can be a great place to store it.

“If we have issues with moisture in the bags, we will put a paper towel in the bottom but our best solution is to do 2 deliveries per week (only accounts at 2lb/wk or more). Costs us more but they never have bad basil.”

What if customers don’t listen to you and still store it in a cooler? Matt has solved this problem by providing a test bunch free of charge so that customers can see the results themselves.

“I’ve had stubborn customers who put the basil in a cooler and I’ll gift a bag of basil (usually .5 lb) and have them sit it out where I decide for a full week. Our record… 100% of them begin keeping the basil in that area after the test run.”

Handle basil gently, as bruising can increase the rate of deterioration. Many Upstart Farmers have found that selling basil packaged in clamshells is helpful for preserving the herb.
>>> Read more on tips for post-harvest care of herbs

Get ready. Get set. Grow.

Upstart Farmers can grow incredible basil to serve to their communities, and it’s definitely a worthwhile herb! Leave comments if you have questions, and don’t forget to check out our other crop posts.

 

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