The subject pretty much says everything. Of 20 seeds I had 12 sprouts and 10 survivors after nearly 4 weeks. 2 of these Pinus parviflora are about 2" tall and the ends of 3 of the needles between the 2 of the are light brown. My question is should I trim that brown off or not? I have them on the windowsill and they all look very healthy being careful how much I water them.