Would a Research Letter make a difference?

<p>I've recently been differed from Harvard and was going to just wait until I get my next letter. However, my parents think that a Recommendation Letter from my old Research teacher would make a difference. He's the deal...</p>

<p>I've been taking a Research class for four years. The first two years I had a wonderful teacher, but he retired after my sophmore year. Now I have another man, who is great on most accounts, but I don't feel as if he would write me too good of a recommendation (he's new to the class and recently I couldn't make a deadline (with my college applications being more important than his class at the moment)). </p>

<p>My parents think that if I were to get my old teacher to write a recommendation for me, it would make a difference because Harvard (and other top schools) have a focus on research. But to do so, I would need to contact the old teacher out of his retirement, whom I haven't spoken to for two years. I'm not sure how good his recommendation would be, and if I should even bother.</p>

<p>Also, I worked as a researcher for a greenhouse last year (connected to this class). Should I get the owner of the greenhouse to write me a recommendation?</p>

<p>Would any of this make a difference? Thank you for your time in advance.</p>