If the skimpy trees are sufficiently tall and reasonably close (15 or 20 feet), why don't you toss your cord over a branch on each tree and suspend your food between the two trees? This usually needs more than the standard fifty feet of bear cord, though.
Some other tricks:
For tossing the rope, I keep one end tied with an overhand loop. I wrap a smallish rock in my bandana and tie off the bandana with a big overhand knot -- the whole package looks like a bandana dumbbell, with one end the knot and the other end the rock. Then I girth-hitch the rope with the loop to the thinner part between the bandana knot and the rock. This stays together nicely for the toss, but if the bandana becomes hung up you can usually jiggle the rope free and let the bandana and rock fall to the ground.
A (much) cheaper alternative to mini-biners: most hardware stores stock small steel snap-links for less than a dollar. Even the smallest ones test to eighty or ninety pounds.
For counterbalancing or a two-tree hang, use a short loop with a prussik knot to attach one of the bags, you can then slide the prussik up the hanging rope as far as you desire before final launch.
For several years, I used a nalgene lexan bottle with about a cup of water in it as the tossing weight. Never broke a bottle, never lost one either. But I don't carry a nalgene bottle anymore and the bandana scheme is simpler -- and bandanas are way cheaper than Nalgene bottles.