i really have no clue when new growth on jujus would lead to dieback or outright death. I doubt anyone has a concrete idea, considering the multitudes of cultivars, and the permutations of age, caliper, and variety of rootstoc involved. But have to hand it to you, youâre actually the first one have come across to say that a brief 27 F spell will not ruin green growth. A prolonged freeze would surely cause diebac, and possible death, especially if the trees are still young, with much thinner stems and having fewer dormant buds(as well as adventitious buds). Some cultivars will also be more hardy than others. I actually have a 1" tall juju seedling which did not drop its leaves the entire winter(having sprouted randomly late november) despite several sub-freezing spells weâve had. May be the rootstoc of choice for those with super frigid winters.
Can safely say though that other fruit trees would suffer more than jujus, since jujus leaf out so much later than conventionals. Here, nigra mulbs seem to be the only species which leaf out later than jujus. On top of being tardy to quicken, the typically dormant bud neath each lateral is another survival mode âappâ which jujus have developed, should a late frost still manages to âhurtâ new growth after it has leafed out. The laterals have an inhibitory effect on the dormant buds on upright growth, so if new growth on laterals turn into green mush after a hard-freeze, the undifferentiated buds will save the day. And the more undifferentiated buds(on older trees), the more likely one or two, or more will be there to assume apical dominance. Undifferentiated buds(especially on lignified stems) are more hardy to freezing than differentiated ones.
there are innumerable centennial juju trees in china, and plenty that have lived at least a thousand years and still productive. Hindsight proof of hardiness to late freezes. I mean, if a tree has lived that long, the chances of it having experienced aberrant weather patterns must have been so much higher, since âperfect weatherâ or zero late frosts in any region anywhere on earth is close to impossible if talking in terms of several centuries.
