If the suckers are growing out of the roots than let them keep growing and if kept watered properly they should take on the role of your main leader trunks. Once they go dormant later in the year, you can dig them up and determine if your suckers are growing from one root system or if the grower had made your Heritiage Birch trees multi- trunked by planting two or three single trees together. If you find that is the case then you can seperate the individual root systems while the trees are dormant. Then you can replant the root systems individually, and be careful not to break off the new trunks, which the current suckers will have begun to form by the end of this growing season. Then wait long enough for these individual trees to become well established, and during that time do not cut off any new suckers which grow. As those new suckers begin to grow from the root systems of the individual suckers you end up planting, then you should let all the new suckers that want to grow to keep growing until you can determine which ones are the most agressive and closest to the same size and trunk diameters. Once you get to that point simply chose how many main leader trunks you want your trees to grow and cut off any other weaker growing ones. The new trees you grow like this should end up growing fairly quickly into nicer trees than these current dead looking ones that you first planted; that is, if you keep them watered properly, stake them if the winds begin to make then sway back and forth too far, and if you are patient enough to allow them to do their thing; they should get to that point over the same three years it would have taken for you currently dead looking trunks to have become well estatablished. Not only a lack of proper watering could have potentially caused your main leader trunks to die, but your tree could have also suffered rootflare breakage as the canopy of your trees, during last growing season, caught strong wind gusts which could have cause the trunks to lean far enough back and forth to break those roots away from the trunk, which would have resulted in the trees failing to be able to take up the amount of avaliable moisture they needed from the soil. This kind of root breakage happens often when people first plant Birch trees that are 5 to 6 foot or more tall with well developed canopies, but which were not staked well enough when first planted.

Trees that have been staked at the nursery don't have a chance to produce 'reaction' wood in response to wind movement. Instead their trunks are weak from being tightly lashed to the stake and being unable to move. Your goal will be to stake your tree according to industry standards, allowing it to move a bit within the smooth ties. Use 2-inch wood stakes and attach an old piece of hose with wire run through it. You should be able to remove the stakes in about a year. Be sure to gradually move your drip emitters out to the edges of the branches as your tree grows. This will leave dryer soil near the trunk and your tree will be less likely to blow over in winds. Here's a link to planting guidelines from the University of Arizona. Research shows that plants installed in this manner established more quickly than using other methods. Here is a link that might be useful: Planting Guidelines

Thats a tough one. Never had to water such sized fresh planted trees. I guess it depends on soil type and current state of your soil from a moisture point of view. Oh and if the plants were containerised or rootballed from a field. I would water a good large amount at reasonable intervals without over watering more than little but often like some people do which often leads to dry areas due to poor water penetration. Then ofcourse you will have to judge on how the spring and summer goes- good luck- I am sure the trees will give you some indications as to if they are happy or not.

I haven't had this issue with birch, but am having issues with buckeye right now. There is too much rain and they put on a quick early burst of growth that is too heavy for the stem. I stake them up - they won't need the stake when it gets drier and growth starts to harden.