Organizing salad greens by yield

When looking at yield data collected this past spring, I found the salad greens I've grown could be roughly categorized into three groups: heavy, mid and light weight.  These distinctions could be useful when building a unique salad mix with some lessor known salad green varieties.

The highest yielding greens were the lettuces and loose headed cabbages.  These make a good basis for a salad mix because they are a) heavy and b) mild tasting.

Medium yield greens contain some of my favorite greens.  Ok, they are all my favorites and when mixed together they make a nice salad.  None of these have any spicy-ness, but they do offer good tastes and nice curvy leaves.  And beets and chard just so pretty.

Spicy mustards, arugula and kale make up the light weight category.  They are 'lofty' and add texture, color and interest to salad mixes.  Often, these are the greens that you don't want too much of in a salad anyway.  I've tried the mainly-mustard-greens salad and it was too much. The keyword there was 'tried.'  Other varieties of kale may produce a heavier yield, but the russian kales have rather spindly leaves when they are young.

What would you choose to put in your salad mix?

Bolted brassicas

Right now the greenhouse is filled with bolted, flowering brassicas.  Most brassicas have yellow flowers.  Arugula flowers are totally different in color - they are cream colored with red viens.  They do have the same number of flower petals and stamens.

Brassica florets are tasty when small, but once the stems elongate and the flowers open they are tough.  Last year I have enough tat soi flowers to eat in a stir fry. This year I let everything bolt.    Brassicas tend to bolt quickly in this greenhouse because there are so many plants in such a small area.

Varieties, clockwise from top left: wasabina, arugula, mizuna, tat soi, chinese pac choi, tokyo bekana.

Arugula seedlings in a petri dish

Yesterday morning I woke up to find the arugula seeds I've sprouted in a petri dish had started to push off their cover.  They are so big I might try sticking them in my garden, filter paper included.  

I have a soft spot for arugula because I grew it for my senior thesis project.  I love its spicy taste - which is totally different from hot mustard greens even though they are both in the Brassicaceae family.  I've been reading all about the brassica family's evolution.  It is just as complicated as any family tree, even though plants don't move.  It's fascinating, and you'll read all about it soon.

Graphing the growth rate of greens

I have now measured 14,400 leaves and weighed 8,505 grams of harvested greens, so it's about time to make some graphs out of all that data. (8.5 kg is almost 20 pounds, which is ALOT of greens.  You could make many, many salads.)

I love making graphs.  Partly because they get to be colorful, but mostly because they take a whole bunch of numbers and organize them.  The graphs below took 12,200 numbers to make. Think about that for a while.

(The y-axis is leaf length in cm.  I forgot to label it.)

This graph shows the growth rate of each variety of green that I planted on 3/20.  I didn't start measuring until the plants had harvestable leaves, which was around the 12th/13th of April.  If you remember my overview of this experiment post at the beginning of April I was hoping to see the growth rate level off.  From this graph you can see that did not happen.  The greens just kept growing and growing.  I had to stop measuring leaf length, not because I ran out of greens, but because the greens ran out of nutrients and looked ugly.  (As shown in the stressed out greens post.)  The little black x's mark the best harvests. 

(The y-axis is harvest weight in grams.  I forgot to label it.)

The graph of harvest weights shows a general trend of continued growth for most varieties.  Toyko benkana and Outrageous lettuce have weird, unexplainable dips in harvest weight near the end.  I don't know what happened to cause that, but it does show why I have to do experiments a few times.

These two graphs aren't everything.  Now that I'm done measuring and harvesting four times a week I'll be using this data (all 14,400 numbers) to extrapolate things like: potential harvest weight, optimal harvesting time and how much money it cost to do all this.  Pretty cool stuff eh?

Stressed out greens

I came into the greenhouse on Monday to find I wasn't the only one stressed out this week.  I'm working on finishing lengthy term papers for the end of the semester.  The greens are stressed out because they are running out of nutrients.  In some varieties stress is shown by leaves turning purplish, in others the leaves bleach to bright yellow.  The tokyo bekana, kale, arugula and tat soi above are all brassicas that were first to reach harvestable size (Mizuna was as well, but I didn't take a picture of it looking stressed out).  So, it makes sense that they would use up all their nutrients first.  I am growing the greens in compost, which should provide all the nutrients needed.  If I were growing these to eat, or for sale I would have harvested them last week before they got stressed out.  

Happily, the lettuces still look good.  Most of the year I am not a supporter of lettuce - it is bland, or bitter and doesn't have as many nutrients as other greens.  At this time of year though, it is perfect!  All green and leafy tasting.  Lettuce is in the Aster family, along with dandelions.  I don't think they are close taxonomic relatives, but I do think that lettuce smells a bit like dandelions.

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.

two weeks of growth!

What a difference just one week can make!

Growth rate of greens (or experiment number two!)

Even though the weather right now is not very winter-like I've started a second experiment.  Describing this one is much simpler:  I am going to see how different varieties of greens grow in the 'cold.'  The same kind of work was done last spring and fall and I'll be doing a lot more of it next winter.  

A few of the greens I'm growing are in this mixed flat.

The goal is to be able to estimate how long it will take green to reach a harvestable size as light and temperature levels change drastically in the fall and spring.  By the end I'd like the be able to say "if you plant lettuce in September you'll be harvesting in late october, but if you plant in october you won't be harvesting until december."

Arugula grown spring 2011

The chart above is a snippet of the data collected last year.  The temperatures are when the greenhouse heaters turn on.  You can see that keeping the greenhouse ten degrees warmer makes a big difference in growth (leaf length).  The length of the arugula grown at 40 degrees seems to be leveling off at around 40 days of growth.  If you knew it was not going to grow anymore you would harvest it at forty days.  Leaving it in the ground won't mean it was going to grow anymore.  The same observation can't be made for the arugula grown at fifty degrees - which is why we need more data!

What's going to happen:

I am growing ten varieties of greens:

1. spinach
2. kale
3. green romaine lettuce
4. red romaine lettuce
5. arugula
6. mizuna
7. tokyo bekana
8. tat soi
9. ruby streaks
10. scarlet frills

I'll make eight harvests at 3 - 10 weeks after planting.

At each harvest I will measure:

• The length of 10 leaves of each species 
• The weight of each species harvested

Pretty simple!  Are there any greens you would like to see on the list?  Leave a comment below and I'll take it into consideration for the next round.

one week of growth

These little guys are only one week old!  They are part of  the new experiment I am working on.  I'll start posting about it in the very near future.

One week of growth

Although I have finished data collection for the germination trials, I have been observing the sprouted seeds as they grow.

Lettuce from white plastic, plastic with holes and clear plastic low tunnel coverings.

I've commented before on the pigmentation of lettuce grown under the different low tunnel treatments.  Those little seedlings have grown quite a bit in two weeks, but the pigmentation patterns continue.

I planted plugs in trays of soil on the 13th of February (on the left).  A week later the greens look fuller and many of the plugs have more leaves.

These pictures of arugula are also from the 13th and 20th of February, respectively.  In just a week the seedlings have gone from cotyledon stage to the true leaf stage.  

Today I am going to plant a few herbs to see how they grow in the tunnels.  I am thinking about dill, cilantro, parsley and basil.  Any other ideas?  What would you like me to try growing?

Why your mom told you to eat your greens

I believe a good diet is balanced.  That being said, the heap of fried seafood I helped consume yesterday totally upset that balance.   It was delicious but, for the next week or so I feel like I should only eat leafy green vegetables.  The kind I ate in giant bites as a kid in order to get them over with as fast as possible.

The kale I planted a month ago is now at the super cute puppy stage.

What makes greens so good for you?  Keeping me from being anemic and getting scurvy where the vague reasons in my head.  Once again I turned to myplate.gov and their "food-a-pedia." This gave me so much information that I have to think about it in small bits.  I chose to compare the greens I am using in the germination trials, as well as my two favorite cooking greens.  (Arugula is a substitute for mizuna because myplate didn't have any information about mizuna.)

data for this graph came from myplate.gov

First nutrient up is folate.  I didn't know what this was, possibly because it isn't on most nutrion labels.  It is one of the B vitamins and awfully important because it helps make and repair your DNA!  In my greens comparison collards were the clear winner for amount of folate per serving.  Interestingly, kale contains the lowest amount.

Of course, folate isn't the only reason greens are good for you.  In the future I'll look at calcium, vitamin C & A, and potassium.

mesclun

Endive, lettuce, arugula and chervil from Johnny's Seed Co.

What is mesclun?  The traditional French mix included only endive, lettuce, arugula and chervil, but now it can include any number of baby greens harvested and mixed together.