Growing Hydroponic Collard Greens

Collard Greens 

Hydroponic Collard Greens
Germination Light EC Range pH Range: Time to Harvest
Easy 12-16 hours 1.6-2.5 5.5-6.8 5-6 weeks
Nutrient and Health Info - Collard greens are are the 10th most nutritionally dense vegetable there is and have loads of vitamin K, and very high amounts of vitamin C and B as well. They’re also rich in calcium, fiber, and iron.
Tips & Tricks - Harvest your collard greens when they are 10" long or less, as they will be less stringy and taste better.


Collard Greens are closely related to Cabbage and Kale, and like Kale, they are packed with nutritional value. According to the CEC, they are the 10th most nutritionally dense vegetable and have loads of vitamin K, and very high amounts of vitamin C and B as well.  They’re also rich in calcium, fiber, and iron.  Collard Greens grow amazingly well in hydroponics, so don’t hesitate to start growing them in your iHarvest® indoor garden.

We’ve been eating collard greens since at least the time of the ancient Greeks and they are enjoyed in Africa, Brazil and all over Europe.  But most American’s know them as a Southern food staple.  During slavery, collard greens were one of only a few vegetables that enslaved Africans were allowed to grow in their ‘kitchen gardens.’   The plants were able to grow throughout Southern winter months and were combined with leftover scraps to make a flavorful meal out of very little.  This traditional Southern meal is called collard greens and they are still cooked in a pot with smoked and salted meats, onions, vinegar, salt and pepper.  The liquid that forms at the bottom of the pot is referred to as Pot Likkur, and is soaked up with bread or used like gravy.

Collard Greens can also be steamed, cooked into chips, used in salads, wraps, sautés, soups and stews.  They are known to taste similar to kale but are slightly less bitter.  The bitterness becomes less intense when cooked.  Harvest your collard greens when they are young and less than 10 inches long for tastier results.

Collard Greens


Collard greens germinate easily, so don’t be scared to give them a try.  You should see seedlings emerge in a week or two at most.  If you have trouble, consider using our Seedling Starter Kit or the paper towel method to help to increase the rate and speed of germination.


Like most vegetables related to cabbage, your collard greens don’t need an exceptional amount of light, but giving them 12-16 hours of artificial light per day will ensure they will grow great with the other plants growing in your garden.

EC Range:

Collard greens will grow best with an EC range of between 1.6 – 2.5.  It pairs well with many other leafy greens and also herbs.  It will grow relatively well at lower EC ranges as well, so you can grow it with lettuce.

pH Range:

Your collard greens grow well in a variety of pH’s.  Simply keep your pH range between 5.5 and 6.8, and you’ll have great results.


Use our Green Machine nutrients to grow collard greens and other leafy greens with amazing success.  They mix incredibly well in your reservoir, and have all the nutrients your greens need to flourish!

Time to Harvest:

There’s not much need for patience when growing collard greens.  They are aggressive growers that can be harvested in 5-6 weeks.

Pruning and Harvesting:

Young collard green leaves taste best, while they will grow quite large it’s best to harvest them at ten inches or less. 

Pot Likker Soup


Collard Greens are a Southern staple that are frankly underused in other areas of the country.  They are extremely healthy and easy to grow.  It’s quite likely that you’ve had them before, perhaps at a restaurant, but didn’t know you were having them.  If you like Kale, you may love collard greens.  Just do yourself a favor and avoid simply boiling them, which can be a bland way of cooking collard greens.

Check Out Our Collard Green Recipes!

Let’s grow together!