Dan, I've seen enough of this disease to diagnose it at a glance - the brown and dried-up, persistent flowers and lack of foliage are extremely characteristic. Like I said, it is endemic to flowering cherries in my area, especially after the soaking wet spring we've had. And yes, you do need to prune back to the viable, healthy leaf growth towards the top of the branches. Now you can understand why I said your little tree will probably never look good - most weeping cherries around here look like someone took a hedge trimmer to the weeping branches all the way around the tree, just to keep this disease in check and to remove the unsightly dead-looking branch tips. By the time one is done with this, there's not much 'weeping' about the tree any longer. I could show you a half dozen just like this in my neighborhood alone and it's not bad pruning - just sick trees :-) I would never, ever recommend planting a weeping cherry in the PNW regardless of how great a bargain it may be or how pretty it looks in bloom at the nursery. It is usually just a waste of money. And I am very cautious about recommending any other type of flowering cherry - these trees have so many issues associated with them in our climate, WSU has published an entire booklet (not a brochure, a multi-page booklet) on problems of ornamental cherries.

Dieback on ornamental cherries in the PNW is very common - one of the many fungal or bacterial problems these trees are prone to here (so many in fact, that WSU published an entire pamphlet on ornamental cherry tree problems). It has nothing to do with fertilizer or lack of it - much more a factor of our weather and the inherent vulnerability of these types of trees. As to fertilizing or not.......never is a very long time and it may very well be that trees and/or shrubs in the landscape will require some sort of nutrient supplementation from time to time. They do pull nutrients from the soil and while they may have a long reach, it is not inconceivable for them to require fertilizer on occasion. But it should not be considered an annual chore but done only as needed. The appearance of the plants and/or a soil test will determine what, if anything is lacking and should be supplemented. And when the time does come to fertilize, throw away the MiracleGro and use a granulated fertilizer (synthetic or organic - your choice) sprinkled around the entire root zone. Foliar fertilizer applications are extremely inefficient and generally a waste of time and fertilizer. Nutrients are absorbed primarily by plant roots and the benefit of foliar applications is minimal. Without photos it's difficult to say exactly what your cherry is suffering from, but brown rot has been very common this season with our cool and wet late spring. FWIW, fertilizing with a high nitrogen fertilizer (like MiracleGro) is not advised as increases the incidence and potency of the fungal problem. "Use only moderate amounts of nitrogen fertilizer such as one application per year of a 5-10-10 or none if the tree is growing normally." (WSU Extension Bulletin)

Me, I would take it back, due to the extent of the damage, and how the tree looks. If they offer a guarantee until Nov., then they should honor it now. They get paid to baby plants, and you should be able to buy a healthy specimen. It IS possible that it got missed a time or two as who-ever was watering at the nursery ran down the rows of plants with the hose, and it got damaged that way. From the photos, it does look like it missed a few waterings. It should come back from it, but it may take a while and it may not be too attractive for a year or so. Just check over your next tree very carefully before you buy it and take it home, and look after it well once you get it there - if you think it's dry from the nursery, water it, and if it's pretty wet, leave it until it's dry. Plant it ASAP (dig the hole before you go to the nursery) and mulch it well - no deeper than 4", as wide as possible, at least 3', and no mulch in the 2-3" next to the trunk. Water it abour every other day for the first week or two, then taper off to once a week or so, as the roots begin to grow out of the root ball into the surrounding soil - a long, slow watering, so the ground gets soaked to the bottom of the root ball. Check if it needs watering by checking the first few inches of soil - if it's dry, water, and if it's still damp, wait another day or 2. You want to give it the equivalent of an inch of rain per week, so adjust your watering according to how much rain you get.

I live in Staten Island, NY. We bought a weeping cherry about 8 years ago. Every year I cut off more dead branches, but haven't seen any new growth. It blooms every year and is covered with green leaves, but some of the tips are dead and need to be pruned again. We have a lot of red clay soil, we had amended a portion of the yard with top soil and peat moss. My husband says the tree looks nothing like a weeping tree anymore, all the branches have been trimmed so it seems to have just a crown of leaves. What can I do to encourage more new growth?