Harvesting Lettuce

 Lettuce is one of the most efficient and rewarding things to grow in hydroponics.  Under good conditions, they usually sprout within about three days; it's actually not unheard of for them to literally sprout overnight.  (Don't be alarmed, though, if it takes a week or two.  There are so many things that can affect how quickly a seed germinates!)  They are ready to begin harvesting just as rapidly, usually starting about a mere 21-24 days after the seeds are started.  It feels like you can literally watch the little plants growing in real time!

But once your baby lettuce is reaching a harvestable size, then what?

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 When it comes to lettuce, there are two primary methods of harvesting: the "haircut" method, where you cut across all, or at least the majority, of leaves at a certain point; and the "leaf at a time" method, where you pick the outside leaves around the plant in a spiral.  Which of the two you use is entirely a personal choice; some swear by one, some the other.  Like most things, both have pros and cons, and so which you choose to employ comes down to your specific garden and goals.  In my personal experience, and reading the experiences of others, this is what I have picked up:

 

 

Haircut Method

With the haircut, you take the entire head, and cut all the leaves about ⅓ - ⅔ of the way down the plant, being careful not to cut the central growth bud.  Be sure to use clean, sharp shears.

 

Lettuce ready for harvesting

After haircut method harvest

  

This method of harvesting absolutely produces larger single harvests; you can get a whole salad from just one or two plants.  This can make it ideal for those who are growing a very limited number of lettuce plants, such as in the smaller AeroGardens (Sprouts and Harvests).

Additionally, adherents to the haircut method swear that the regrowth is faster from the haircut method than from harvesting leaf at a time.

One day after harvest

Six days after harvest

However, the downside of haircut harvesting, is that with the stress induced by having to regrow most of its foliage after each harvest, you only get 2-4 good harvests from each plant before they bolt.  They are done by about 2½-3 months.

One final consideration, is the type of lettuce.  While this method works quite well on the more upright varieties like romaines, it can be more challenging with more 'heading' varieties, like butter and bibb lettuces, to take enough of the leaves without cutting the growth bud, which can slow, damage, or even prevent regrowth.

Leaf at a Time Method

This is my personally preferred method, and I use it exclusively until the final harvest when a plant has begun to bolt.

With leaf at a time harvesting, you pick whole individual leaves working from the outside of the plant in.  Individual harvests are smaller than with the haircut method, as you only take a few leaves from each plant.  However, the harvests are steadier: with haircut you can only harvest about once per week or ten days for each plant, while with the leaf at a time, you can harvest every day to every three days, depending on how severe each harvest is.

Farm ready for harvest, left side

Farm ready for harvest, right side

Before harvest

 

It is also an ideal choice for those like myself (see pictures) who grow multiple different varieties of lettuce.  You get a little bit from each head, so you don't end up with an entire bowl of just one type.  This is ideal, to me; I wouldn't want an entire salad of just spicy red mustard, while having a bite here and there with that mustard kick is lovely.  Also, because you take the lettuce leaf all the way down to the stem, you get the entire crunchy central rib - my favorite part of the lettuce! - most of which gets left behind in the haircut method.

After harvest, left side

After harvest, right side

After harvest, with packed 40 oz. bowl salads

In my AeroGarden Farm pictured, I have 16 pods with a dozen different lettuce varieties, and get two large meal-sized salads every other day.  Additionally, my lettuce frequently lasts four, five, or even six months, instead of less than three.  However, very regular harvesting is key to this longevity.  Instead of a few severe cuts that badly stress the plant, you keep it at a constant low level of stress, always working to replace lost leaves.  Going even a few extra days between harvests can lead to bolting plants - which, again, simply because of the regrowth time required, is inevitable with the haircut method.

(Haircut Method photos by Jenn Badiang Alberti, used gratefully by permission)