Growth rate of green romaine

Back when I first described the growth rate experiment I'm working on now, I described how I was hoping to see growth rate level off so you could predict how long your greens needed to grow before reaching optimum harvest-ablity.  Only half way through data collection and I am started to see that happening!

Growth rate hasn't slowed down in some species, but it seems to be slowing in the green romaine variety we're using called 'Defender.'  The graph below shows leaf length and harvest weight over a period of about two weeks.  The last time I collected data was April 26th.  Neither the leaf length of harvest weight had increased much since the last time I collected data (three days earlier).  Tomorrow I'll see if this trend continues.

What to do with all these greens!

From yesterday's picture you might have guessed that I have a lot of salad greens in my fridge right now.  A LOT.  Some nights all we eat is salad.  If you filled up a salad bowl with greens, grabbed a fork and dug in you would know how I feel.  I am certainly not complaining!  Just ready for some salad green diversity.  Yesterday I lucked out big time.  

Two days ago was harvest day for UNH study on growing cherry tomatoes in hanging baskets.  (I looked briefly online to see if there was anything written about this study - not yet it seems.)  So, for dinner I had: tomatoes, garlic, chopped mizuna and spinach all covered in olive oil on toast.  And there was cheese on top.  From the picture you can tell I'm not going to be a food blogger anytime soon.  It smelled too good to take a good picture.

What would you do with 'extra' salad greens?

Five weeks old today!

Everything that's growing (except arugula)

Scarlett frills, tokyo bekana, mizuna, red romaine, red russian kale, 

green romaine, tatsoi, spinach, ruby streaks

plant profile: kale

Without meaning to I've neglected to say anything about kale.  I am not not quite sure if I like eating kale as a salad green, which may be why I haven't written anything about it.

Don't get me wrong, I love kale, but I prefer it cooked.  As a baby green it seems rather frilly and tasteless compared to the other mustard greens I'm growing right now.  Since I've been collecting growth data for two weeks now I can say that kale has been steadily growing, so maybe I'll change my mind by next week. 

 After every harvest I photograph a few representative leaves of each species.  When I'm done with the study I'm going to put the pictures together along with graphs to really show the growth rate of each salad green.  Right now I don't have enough data points to make a worthwhile graph, but I think the photos of kale growth look pretty nice.

 I'm growing red russian kale, which is a pretty typical variety.  Maybe a different variety would be a better salad green?  My favorite is white russian because it is sweet and tender in comparison to red russian.  Siberian kale is advertised as being good raw, so I better try it next fall.

Scarlett and Ruby

Meet Scarlett and Ruby, two of the mustard greens that are being measured and weighed during the next few weeks.  During the summer I hated harvesting this kind of green because they were always frilly, bolting and never amounted to very much.  

I thought these two greens would be pretty much the same thing: dark red frilly mustard greens.  But they are definitely not!  Scarlett Frills is darker with skinny leaves.  Ruby Streaks is reddish and bright green.  It's far 'frilly-er' (and I think prettier).

four weeks of growth - it's time to eat!

All the greens are not 'full size' yet, but the kale, mizuna, tokyo bekana, tatsoi and scarlett frills are!

Measuring growth rate by weight

Last week I wrote about tracking growth rate by measuring leaf length.  This week I started tracking harvest weight as well.  Here's what I do:

First I measure leaf length of ten leaves in a quadrant (same as before - this is still useful data to collect!).  Then I harvest all the leaves from the quadrant.  I don't cut at the soil level for two reasons: when you are harvesting salad greens you don't want the stem-y bits, you just want the leafy bits.  Also, if you leave the shoot apex (where new leaves come from) more leaves will grow and you'll be able to harvest a second crop from the same plants.

Bottom right quadrant harvested. 

 Next, all the leaves from the harvested quadrant get weighed.  Can you tell what green I am harvesting in these pictures?

Everything gets recorded in my lab notebook.  On the far left I identify the replicate, tray and quadrant I am measuring.  Then come the ten leaf lengths, and on the far right is the weight of all the leaves in that quadrant.  Eventually, I'll stick all the data into the computer and analyze it, but right now measuring, weighing and watering is enough to keep me busy.

three weeks of growth!

Can you name any of the greens yet?

How to measure growth rate

 Now that the greens are big enough I've started measuring their growth.  Yesterday was the first day of data collection. (You can see the experiment overview here.)

For each variety I measure the length of ten randomly selected leaves.  There are four replicates of each variety, so there are a total of 40 leaf measurements for each type of green.  I'm going to do this twice a week for the next 6-8 weeks.  All this data should make a lovely graph showing when the plant is doing most of its growth, and when it has reached maturity.

I use very fancy equipment when collecting data.

Next week I am going to start harvesting and weighing samples of greens as another measurement of growth rate.