It is hard to tell from your posting whether the trees have been in the ground for a number of years or if they are newly planted. If they have been there for a while, then watering MAY not be the problem. Check around the roots and see if it is especially dry. Mulching would help keep whatever moisture there may be at the root level, to do some good, since I am assuming that it's more likely to be dry than wet. If it doesn't seem to be moisture that is the problem, I would take a few branches/twigs/leaves to your county extension agent - look in the phone book under state or county agencies - and see what they can tell you. You can also take them to a GOOD nursery, if there is such in your area, and try to talk to the manager/owner. If you talk to one of the employees, they MAY not know anything - I would be slightly suspicious of any response that immediately tries to sell you "this great product", although, in fairness, you may need one or the other of the products! If the trees are newly planted (within the past year), then probably, since you say you are in drought conditions again, they need more water. You can save the water that you run in the kitchen or bath faucets, waiting for the hot water to get there, and use that for watering - I would use most of a bucket on only a few plants, rather than a bit on all of them, as that way the whole root system will get wet. If you can't do that, then I can't think of what else it might be of use - posting a photo would help.

I had a few Callistemon citrinus growing in the garden for a while, but the last one froze out in 2004 when the temperature dropped to about 22F in the most sheltered part of my garden where it was planted. I also don't have hope for any forms of C. viminalis which would include 'Little John'. Last December was a good test for Callistemons when the temperature dropped to the range of 12-14F with nearly a week entirely below freezing early in the month. Undamaged by this event were C. sieberi (several forms), C. viridiflorus, Callistemon sp. aff salignus, and a few unknown dwarf ones that may be forms of, or closely related to, C. sieberi/pityoides. All of the above have cream or yellow flowers. The hardiest red-flowered species such as C. subulatus, and 'Woodlander's Hardy' mostly had minor to moderate damage, and though none were totally undamaged, I was impressed that these did pretty well overall. I would also place all forms of C. pallidus in this category. Everything else froze to the ground, including anything with purple flowers, and C. montanus, macropunctataus, rigidus, a pink form of C. sieberi, and several more unknown ones. Too bad. Callistemons are pretty good at growing back from the roots if they are cut to the ground, so perhaps they will return if summer ever arrives this year.

That hollow bit at the bottom appears to be where a branch (fork) has been ripped away at some stage. If it were mine, I'd probably be inclined to lop it back down close to where it was pruned last time, or lower and keep it pruned each year to encourage a good bushy habit.

I learned that the hard way the 1st year I gathered them. I put them in the garage & they all shriveled on me. not at all like the buckeyes on trees. now I plant them right away or store them in a mix of damp sawdust & potting soil. the harvest is nearly done for this year. I do not pick them until the husk starts to open. the trick is getting them before the squirrels do. I shot a squirrels yesterday with one in it's mouth.