A friend has just given me two bare root Granny Smith trees and have a couple of questions. One of them is about pollination, is there anything I need to bear in mind, on the allotment I already have another apple tree (Fuji), pear, plum, apricot and cherry. Is it ok to put them in now? It's freezing at night (down to about -4º recently) but sunny and warmish during the day. Cheers.