Introduction

Most microgreen farmers operate under similar conditions - indoors and climate-controlled. Despite having similar setups, everybody has their method for growing each variety. I’ll explain how I grow basil microgreens at my company, Piedmont Microgreens (PMG). We grow 400+ trays per week (TPW) at PMG, and 10% of those are some form of basil - Genovese, purple, or lemon. Here are the farm's parameters and the conditions for growing our microgreens. Yes, the relative humidity (RH) is high. I want the RH to be between 45-55%, but we’re working on it. Regardless, our crops grow well and we don’t have any issues with disease. We fertilize all crops with one dosing of dilute Ocean Solution. We dilute one ounce of Ocean Solution to a gallon of water. Every tray gets fertilized first thing out of germination. The rest of their life they get regular city water.

Avg. Farm Temperature	75°F/24°C
Avg. Farm Humidity (RH)	65-72%
Lights On	16 Hours
Lights Off	8 Hours
Shelf Spacing	10”
Lighting	2*T5 LEDs 22W/Shelf
Soil	Promix BX
Trays	1020 Shallow
Water	Municipal, Bottom Watering
Fertilizer	Ocean Solution

Growing Basil Microgreens

Basil was one of the trickiest crops for us to learn to grow. The outcome of our grows for a long time were always spotty. Some weeks the basil would look great; other weeks it would yellow or blacken before harvest. We recently discovered it needed more nutrients than most microgreens because its grow time is much longer. At a 24-day grow, basil is one of our longest growing crops. I say basil as if it were one item, but we grow three varieties - Genovese, purple, and lemon. Genovese makes up 90-95% of the basil trays, though. The crop info below is for Genovese. Our tests show that lemon and purple varieties grow to the same size 4-7 days faster. Regardless, we use the same seed density for all three varieties and we get similar yields of 3.5-4 ounces per tray. In the introduction, we said that every tray gets one dose of dilute Ocean Solution after germination. Our basil trays also receive an additional dosing once per week until harvest. We find that this extra nutrient boost staves off discoloration or stunting until harvest.

Sprinkle your 4g of basil seed across a tamped 1020 tray of soil. Be extra careful with basil. Its seeds are tiny and black, so they are hard to see when seeding. The seed density is very low, which makes an even distribution across the tray more important than with other varieties. Clumping of seed will prevent even growth of the basil over an otherwise long grow time. If your seeds aren't spaced evenly, some basil will be too big or too small at harvest. The variable growth rate is because of the competition for space, or lack thereof. We don’t see this affect other varieties as much. The seeds are easier to see when planting and the grow times are shorter. So, there’s less chance of a growth disparity. After sowing, use a watering wand to hydrate the seed and soil. After you wet the basil, you’ll see them change color and develop a gelatinous layer around the seed. Basil, arugula, and chia seeds are common varieties with mucilaginous seeds. This layer of hydrogel protects the seed and keeps it from drying out during germination. The gelatinous layer isn’t as prominent with arugula, which is why we stack and weigh down arugula during germination. However, the gelatinous layer is much more pronounced with basil. If we stacked and weighed down basil for germination, the seeds would stick to the next tray in the stack. As a result, we germinate our basil varieties under humidity domes.

After 5-7 days under a humidity dome, the basil trays are ready for the lights. Basil is one of the shortest crops, which makes it harder to cut at harvest. If you grow basil for less than three weeks, try a blackout phase for 1-2 days before putting it under lights. A blackout phase will help the stems elongate, which makes for taller crops at harvest. Basil is so light and fluffy that we struggle to fit eight ounces of product into a 64-ounce container, like we do with most other varieties. When selling to distributors, we price basil at eight ounces, which is a standard weight for most wholesalers. However, we pack only four ounces per clamshell and we give them two clamshells per order of basil.

Basil is one of the shortest shelf life crops in our farm. Basil has a reputation for being fast to spoil regardless of it being a microgreen or a mature crop. Basil is also unique in that it doesn’t like standard fridge temperatures. Many distributors have separate cold storage areas for basil and other crops. These fridges are set to the low 50s. For both reasons, we always harvest basil on delivery day, and we avoid putting it in our fridges before delivery.

Product Size	Container Size	Price	Client Type
2 oz.	32 oz.	$16.00	Restaurants
8 oz.	2 x 64 oz. (4 oz. per)	$32.00	Distributors

Preferred Supplier	Johnny’s
Preferred Variety	Genovese, Red Rubin (Purple), Lemon
Sow Density	4g/Tray
Est. Seed Cost/Tray	$0.20 - $0.80 (Buying 1# of Seed)
Est. Gross Margin/Tray	82% (Restaurants)
Popularity Level	8/10 (Top 5)
Difficulty of Growing	Advanced