dementia13 wrote:

Hi, all. I planted a Sourwood in April, and it did well through June,
when it went into a rapid decline. It's still under warranty from the
nursery, but before I get it replaced I want to make sure the same thing
doesn't happen to the replacement. (And before you say "Google", it
didn't help). Here's the detailed timeline:
Early April: purchased 8' tree, set it into ground in what was to be a
raised bed; but couldn't be completed because the tiller broke down.
Mounded soil (mixture of native heavy clay, topsoil, peat, and manure)
to height the bed would be and planted. Stupidly, planted tree in wrong
spot and had to move it 2 feet over a couple of weeks later. Tree
healthy, plenty of new growth. A Sweet Bay Magnolia was planted at the
same time; it has remained completely healthy.
Early May: Tornadoes hit; top 18" broken off of tree but no other damage.
Blooms begin to form shortly after.
Early June: Fill in rest of bed. Because the tree was planted in mounded
soil, no additional dirt was placed over roots. Same soil mixture. Added
an ounce of Azalea-Rhododendron fertilizer (because Sourwood is in the
same family) and a small amount of aluminum sulfate; worked these in the
soil with some manure.
Mid-June: Tree in full bloom, but leaves starting to look transparent
and taking on fall color. Coincides with summer heat arriving.
Late June: Leaves dry up. They have not fallen yet, but are orange and
bone-dry.
Should I not have added fertilizer or aluminum sulfate, even in the
conservative amounts that I did? Could my cats have overfertilized the
tree? Could the tree have been stressed from the tornado, and not been
able to handle the additional stress of summer heat? It's planted in
full sun, in Zone 7, with good drainage. (I'm one county outside this
tree's natural range). This tree was at the nursery a year ago, so this
climate is not strange to it.

Sounds like it might be a combination of problems. Despite other posts to the
contrary, sourwoods are very tolerant of full sun locations (Dirr recommends
full sun to part shade), but that combined with abrupt high heat may have
been too stressful to a newly planted tree, specially if watering was not
attended to sufficiently. And most nursery-grown stock is usually grown in
full sun conditions, so this situation should not be anything new to your
tree. I doubt the tornado had much effect other than the deformation and the
damage, which a healthy tree should be able to withstand.

FWIW, professionals generally shy away from fertilizing anything newly
planted - transplant shock and the process of establishment is enough of a
stress to a young tree - fertilizing only compounds the stress. If anything,
use a transplant or root developing fertilizer. Mycorrhiza fungi should help
as well.

I'd just keep it well watered throughout the summer and hope for the best.
Many trees which experience foliage damage from lack of water, sun scorch or
other stress will refoliate, perhaps this season, perhaps next spring. It's
too soon to call it a goner.

I have a sourwood that I've had for about 3 years now, still in the original
nursery container (yes, I know, I'm a plant abuser) as its ultimate home base
has not yet been prepared for planting. Keep meaning to pot it up a size or
two, but so far haven't gotten to it. Despite the mistreatment this tree has
received (the occasional missed watering, retarded root development, etc.),
it still is doing fine although foliage and flowering are skimpy. These are
pretty tough little fellows.

pam - gardengal