Pinching Dahlia Seedlings

My Dahlia seedlings are doing well and I would not consider them to be "leggy" but they have awhile to go in their small 6 pack cells before I will have enough grow light room to pot them up into larger accommodations.  So they need to be size controlled.  Pinching back will not only control their height, but will encourage them to put out two thicker sprouts in place of the single leader, making them bushier.  In the case of flowering plants, this also means, potentially, twice as many flowers per plant.  Pinching back can begin when the plants have three sets of true leaves.

Using a pair of snips, or simply breaking off with your fingers, you remove the growth tip and maybe a set of leaves.  There should be at least two sets of true leaves left.

In this example, I could have gone down one more set of leaves.  In the photo below I have illustrated where two new "axillary buds" will emerge from the leaf "nodes" and form new stems.

 If you were interested in propagating more plants, you could use these cuttings to root more.  I have no idea what the characteristics of these plants will be since they are first season, cross pollinated plants.  I don't need any more of them.  If these plants were sprouting from tubers, and therefore clones of a known variety, they may be worth saving.

It only took me a few minutes to clean the dried cotyledons and pinch back all of the seedlings by a third.  All of the plants look nice and healthy.  Some are taller and some are very compact with little stem length between the sets of leaves.  It was tempting just to cull the taller, rangier plants right now and only grow on the short, compact ones as this growth habit will continue throughout their lives.

I had a nice surprise today as I was poking around in the seedling trays.  My Cherry Tomato variety "Dwarf Eagle Smiley" is finally sprouting.  These seeds were sown on March 5th.  That's 28 days!  All of the other Dwarf Tomatoes and Ornamental Peppers I sowed in that week are already inches high.  These seeds are TINY for a Tomato seed.  Last year they took weeks as well.  in fact, last year I gave up on them, chalked it up to bad seeds, and then Surprise! -they popped out in an abandoned cell tray after I had given up hope.  So this year, I just left them where they were on the heat mat and kept them watered.  What finicky little divas.  Next year I will choose a similar Dwarf Cherry.  I really like the variety a lot but if they are going to be so hard to grow....  I don't need the hassle.

And he's not out of the woods yet.  As you can see, the cotyledons have not broken out of and shed the seed coat yet.  They are still encased and will need moisture to help them break out.  I misted the poor little guy and left him alone.  There are at least five other seeds in there.  We'll see if any survive to adulthood.