Purple
Kohlrabi
Brassica oleracea L.
Purple Kohlrabi are super easy-to-grow, flavorful microgreens that make a fantastic base for any salad. The beautiful purple stems and bold green cotyledons make them a perfect addition to any dish.
Quick Grow Info:
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Scientific Name: Brassica oleracea L. var. gongylodes L.
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Flavor: Mild Cabbage, Broccoli Flavor
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Seed Rate: 20g-25g per 10″ x 20″ tray
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Seeds Per in2: 0.1g-0.125g
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Pre-Soak: No
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Weight Duration: 2-3 Days
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Germination Time: 2-3 Days
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Blackout Time: 2-3 Days
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Seed To Harvest: 8-12 Days
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Growing Difficulty: Easy
Did You Know
Fun Fact
Scott Robb (USA) grew a world record-breaking kohlrabi, weighing in at 96.95 lb (43.98kg) at the Alaska State Fair, Palmer, Alaska, USA, on the 30th of August 2006.
Plant Details &
Grow Guide
Growing Purple Kohlrabi Microgreens
Purple Kohlrabi is one of the easiest microgreens you can grow. It’s gaining popularity due to its vibrant magenta to white-colored stems and beautiful contrasting cotyledons.
They have a slightly sweet, mild cabbage flavor. It’s a perfect addition to sandwiches and salads. Not only do they taste great but due to its gorgeous colors they’re perfect for making a dish pop as a garnish. They can be harvested anywhere from 8-12 days. So let’s get started!
Step 1 Measuring & Preparing Your Seeds
First, you need to measure your seeds using a scale. The best seeding rate for a 10″ × 20″ tray is 20-25 grams. If you plan to grow them in a 10″ × 10″ tray then simply divide the total amount by two, in this case, 10-12.5 grams.
You can also just eyeball it without weighing, just make sure that your seeds are approx ⅛-¼” (3-6mm) apart.
Once you’ve measured out your seeds you do not need to wash and pre-soak them. This is because the seeds are small about 2mm in diameter, and wetting them will make it harder in spreading them evenly on your growing medium.
Step 2 Sowing Your Seeds
Fill your tray with your preferred medium, it can be soil, potting mix, coco coir, etc, leaving 1-2cm of empty space from the tray edge to the soil level.
Leaving a small space between the tray edge and grow medium helps when it comes to harvesting, minimizing the chance of digging into the medium with your knife.
Make sure you level your medium with your hands so it’s not clumpy, you don’t want your seeds grouping together when you sow them.
First, mist your medium with a spray bottle so it’s damp but not saturated, I recommend this because when you sow your seeds they won’t bounce around and instead stick to the medium.
Spread your seeds across the medium making sure they’re evenly spread out. Lastly, mist your seeds so they’re all covered with a fine mist of water.
Step 3 Germination & Weight Period
Grab an empty tray with no holes and place it on top of your sowed seeds. I use a 15lb (6.80kg) paving block for 10″ × 20″ trays or a 7lb (3.17 kg) brick on 10″ × 10″ trays.
This helps the seed radicle to bury into the medium when it emerges. Without weight, the radicles have a tougher time digging into the growing medium.
Keep in mind that the seeds will germinate while they’re covered and weighed down. A lot of people confuse the germination and weight period to be independent of one another and that you add them together, this is incorrect.
The germination time is there to give you an idea by what time the seeds will germinate, but you don’t add the germination time and blackout period together.
While your seeds are germinating and are weighed down you will need to keep your medium moist. You can do this by lightly misting your seeds every 12 hours, once in the morning and once at night.
Step 4 Blackout Time
After 2-3 days of weight period, the seeds should have germinated and the seedlings should now be lifting the tray with the weight in it. It’s now time to remove the weight and start the blackout period.
Take out the weight from your empty tray and flip it upside down to create a blackout dome and place it back over your seeds.
Keeping them in the dark for 2-3 days will force the freshly sprouted seedlings to stretch and search for light allowing them to get some height.
You can now start bottom watering your microgreens. To do this you simply add water to your bottom drain tray. I personally add 1 cup of water twice a day (every 12 hours), once in the morning and once in the evening.
When the 2-3 days of blackout time have passed you can remove the top tray/blackout dome and introduce your microgreens to light. I’ve found that 17 hours under lights and 7 hours with the lights off work well for me.
Grow your purple kohlrabi anywhere from 8-12 days, following with daily watering of 2 cups per day, once every 12 hours.
Step 5 Harvest
Harvesting your microgreens is straightforward that only requires a sharp tool. Personally, I absolutely love using the Green Mercer Produce Knife—I highly recommend it! But if you prefer scissors, that’s also completely fine; just make sure they’re sharp!
Now, here’s an important tip to keep your harvest pristine; make sure to keep your chosen tool (whether it’s a knife or scissors) away from the soil! It’s imperative in avoiding any accidental contact between the blade and the soil, you don’t want any unwanted dirt from sneaking into your microgreen harvest and contaminating it.
By following this important pointer, you’ll ensure that your harvested microgreens are of top notch quality and purity.
Plant Details & Taxonomy
Kohlrabi, also known as Brassica oleracea L. var. gongylodes L., is a biennial vegetable that thrives in cooler seasons and belongs to the Brassicaceae family.
Kohlrabi seeds weigh between 220-280 seeds per gram.
Consider adding purple kohlrabi microgreens if you’re looking for a colorful addition to your salads, slaws, or sandwiches.
These microgreens have vibrant purple stems that contrast with their green cotyledons.
They have a bold taste and a crunchy texture, similar to cabbage and broccoli.
| Rank | Scientific Name |
| Kingdom | Plantae – Plants |
| Subkingdom | Tracheobionta – Vascular plants |
| Superdivision | Spermatophyta – Seed plants |
| Division | Magnoliophyta – Flowering plants |
| Class | Magnoliopsida – Dicotyledons |
| Subclass | Dilleniidae |
| Order | Capparales |
| Family | Brassicaceae – Mustard family |
| Genus | Brassica L. – mustard |
| Species | Brassica oleracea L. – cabbage |
| Variety | Brassica oleracea L. var. gongylodes – kohlrabi |
| Common Names | Purple Kohlrabi, Purple Kohlrabi Vienna, Knol-khol, German turnip |
Microgreen Pests & Diseases
The following are the most common pests and diseases that can affect your microgreens.
White Mold – Sclerotinia sclerotiorum
Sclerotinia sclerotiorum is a necrotrophic fungal disease that causes what’s known as white mold, it can infect over 400 plant species worldwide. It’s also called cottony soft rot, stem rot, watery soft rot, crown rot, and seedling blight.
S. sclerotiorum key properties are its ability to create sclerotia which are its black resting structures, and mycelium which are the white fuzzy spiderweb-like growths you see on stems and growing medium.
Damping Off
Damping-off is an umbrella term that covers fungi and fungi-like organisms in several genera including Rhizoctonia, Botrytis, Phytophthora, and Fusarium, with the soil fungus Pythium being the often culprit.
Damping-off is a soil-borne fungal disease that affects seeds and seedlings typically by rotting of the stems and roots at and below the soil surface.
When a seed germinates the seedling will emerge fine but within 24 hours to a few days will become mushy and water-soaked, collapse at the base of the stem and die.
Aphids – Aphidoidea
Aphids suck! Quite literally. They’re soft-bodied insects that use their piercing-sucking mouths to feed on plants and there are over 4,000 aphid species in the world.
Other common names are greenflies, blackflies, and plant lice. They come in varying colors such as light green, black, white, brown, gray, or yellow.
When aphids feed on plants they secrete a sticky fluid which is called honeydew (no, don’t eat it). This goo they leave behind drips onto plants and can attract other pests such as ants. If the honeydew is left on leaves it can promote black sooty mold.
Purple Kohlrabi Nutrition Facts
Purple kohlrabi microgreens are low in calories, with just 23 Kcal per serving.
They are packed with essential vitamins and minerals, including Vitamin A (195% RDA), Vitamin K (1140µg, 950% RDA), and calcium (21.50% RDA).
These microgreens are also rich in dietary fiber, providing 6.7g (18% RDA) per serving, promoting healthy digestion.
Use them to enhance your dishes’ nutritional value and visual appeal by adding them to salads, wraps, or garnish.
| Principle | Nutrient Value | Unit | RDA |
| Energy | 23 | Kcal | 1% |
| Carbohydrates | 0.33 | g | 0% |
| Protein | 2.46 | g | 4% |
| Total Fat | 2.46 | g | 4% |
| Cholesterol | 0 | mg | 0% |
| Dietary Fiber | 6.7 | g | 18% |
| Vitamins | |||
| Folate | 85 | µg | 21% |
| Selenium, Se | 0.9 | µg | 2% |
| Vitamin A | 146 | µg | 195% |
| Vitamin B1 (Thiamin) | 0.027 | mg | 2% |
| Vitamin B2 (Riboflavin) | 0.158 | mg | 12% |
| Vitamin B3 (Niacin) | 0.658 | mg | 4% |
| Vitamin B5 (Pantothenic acid) | 0.064 | mg | 13% |
| Vitamin B-6 (Pyridoxin) | 0.192 | mg | 15% |
| Vitamin C | 43.3 | mg | 48% |
| Vitamin E | 1.2 | mg | 8% |
| Vitamin K | 1140 | µg | 950% |
| Electrolytes | |||
| Sodium, Na | 20 | mg | 1.33% |
| Potassium, K | 611 | mg | 13.00% |
| Minerals | |||
| Calcium, Ca | 215 | mg | 21.50% |
| Copper, Cu | 0.162 | mg | 18.00% |
| Iron, Fe | 2.32 | mg | 29.00% |
| Magnesium, Mg | 55 | mg | 13.41% |
| Manganese, Mn | 0.885 | mg | 38.48% |
| Phosphorus, P | 50 | mg | 7.14% |
| Zinc, Zn | 0.9 | mg | 8.18% |
| Phytonutrients | |||
| β-Carotene, beta | 0 | µg | 0.00% |
| α-Carotene, alpha | 0 | µg | 0.00% |
| Lutein + zeaxanthin | 0 | µg | 0.00% |
Recommended Products
Explore my top curated picks for products needed to grow microgreens. Rest assured that all the featured items and products have been meticulously put to the test by me or have received glowing recommendations from my esteemed readers.
Microgreen Grow Trays
For my personal home use, these microgreen trays are my go to. Measuring around 12.2 x 9.06 x 1.77 inches (31 x 23 x 4.5 cm), these trays are perfectly suited for cultivating microgreens in a home microgreen grow room. What’s more, they’re durable, and cleaning them is a walk in the park, making them an all-around convenient choice.
1020 Microgreen Trays – Shallow Extra Strength Colors
Industry leading BootStrap Farmers 1020 microgreen trays! Designed with long lasting durability in mind, these colorful trays are built to withstand years of use and abuse. With a height of 1¼ inches (3.2 cm), these shallow trays make harvests easy, saving you time and increasing your yield. The trays come equipped with 36 drainage holes that effectively remove excess water, promoting a healthy growing environment and preventing mold growth. If you’re serious about growing microgreens and want the best trays available on the market, these trays are it!
