For watering in that very tight space, I suggest to get a hold of some poly tubing. 1/2", 3/8" or 1/4" makes not difference. You'll also need a Tee of whatever size hose you have. Cut a length of tube that would circle the main stem and terminate both ends at the Tee. Drill small holes in an opposing pattern so you'll have a hole aiming inward, then a few inches drill a hole to aim outward and repeat till you get to the other side. This DIY water halo can then be attached to a res and pump, or you can run it to link up with a funnel for those that wish to hand water. All the materials needed shouldn't cost more than a buck or pound and when you have your 2 main branches hovering above the deck just an inch or two, you wont have to worry about moving things around or splash back that burns leaves.