Lettuce Companion Planting Plan

We previously completed our Corn Companion Planting Plan, our Tomato Companion Planting Plan and our Broccoli Companion Planting Plan.  That accounts for 5 of our 7 soil beds.  Now we need to complete our Planting Plan for our lettuce.  As always, we'll reference the Purdue University Agricultural Extension Service's Indiana Vegetable Planting Calendar for determining our dates.  Lettuce is supposed to be planted at 10" intervals.  Our intent is going to be to simply pick the outer leaves of the heads as they mature, thus keeping the overcrowding down.  The allies for lettuce are beet, cabbage, carrots, onion, radish and strawberry.  We don't eat beets, cabbage or radishes so per our Golden Rules, we won't be planting those.  That leaves carrots and strawberries.  Since strawberries are perennial, they'll be having a patch of their own and won't be in our annual beds.  Looks like it will be lettuce and carrots in this soil bed.  That led to the following Planting Plan for our lettuce squares: 

The green circles represent lettuce while the orange triangles represent carrots.  Each little square in the background grid represents 1/2".  Using this plan we should get the following yield from our garden:

Lettuce, Romaine, 57 days to maturity, row planted at 10" intervals, yield 50 lbs / 100' row.  With our layout above and the intended continuous harvest, there would be 6 plants per square foot.  The 57 DTM on our chosen variety provides us the ability to yield three crops in the 180 day season.  Lettuce doesn't like to grow in hot weather so we'll plan on allowing the second crop some extra time, bumping the first and last crops out to the extremes of our planting dates.  Thus:

3 crops X 6 plants per square ft X 0.5 lbs/ft X 24 square feet = 216 lbs of lettuce.

Since my wife loves Boston Butterhead lettuce, we'll split 50/50 in this bed for that variety as well.

Lettuce, Butterball, 52 days to maturity, row planted at 10" intervals, yield 50 lbs / 100' row.  With our layout above and the intended continuous harvest, there would be 6 plants per square foot.  The 52 DTM on our chosen variety provides us the ability to yield three crops in the 180 day season.  Lettuce doesn't like to grow in hot weather so we'll plan on allowing the second crop some extra time, bumping the first and last crops out to the extremes of our planting dates.  Thus:

3 crops X 6 plants per square ft X 0.5 lbs/ft X 24 square feet = 216 lbs of lettuce.

Carrots, 56 days to maturity.  Unlike the corn, we'll produce 3 crops for the season.  Considering a 2.5 ounce average weight for the carrots, yield would be thus:

3 crops X 10 plants per square ft X 2.5 ounces (0.15625 lbs) X 48 square feet = 225 lbs of carrots.

Seeds required for the two beds:
Lettuce - 24 X 6 X 3 = 432 @ 250 seeds/pack = 2 packs X $4.95 = $9.90
Lettuce (Butterball) - 24 X 6 X 3 = 432 @ 250 seeds/pack = 2 packs X $4.95 = $9.90
Carrots - 48 X 10 X 3 = 1440 @ 250 seeds/pack = 6 packs X $3.95 = $23.70

Now we need to determine the planting dates for these.  The earliest we can plant our lettuce is April 1st.  This is some two weeks before the last spring frost, but lettuce is super hardy so it's OK to plan at this time.  Given the the 57 DTM we'll have our first harvest on May 28th.

The carrots has an earliest sowing date of April 10th.  With their 56 DTM we'll have first harvest on June 5th.