Mike Dana, Extension Landscape Horticulture Specialist,
Department of Horticulture, Purdue University
Sometimes, the merciful thing to do is put
a plant out of its misery. This crabapple was a very poor choice as a street
tree from the beginning, with too little space and a spreading
natural tree form which was incompatible with adjacent sidewalk
and parking functions. It might have been pruned into a
single-trunk tree very early and perhaps made into a more useful
plant in this location, but that opportunity was missed. Thus,
over the years, it has been hacked into submission on all sides.
The question was raised as to whether there
was a remedial pruning approach that could make something useful
and attractive out of this tree. The answer is clearly
Replacement, with a slender, upright (perhaps even columnar)
tree form, pruned high so the lowest limbs will not conflict
with traffic (truck, auto or pedestrian) is indicated.
Click on image to enlarge
Galling Situation on Junipers
Karen Rane and Gail Ruhl, Plant Disease Diagnosticians,
Cedar-apple rust is a fungal disease that is quite
common in the Midwest. Rust fungi have very complex life
cycles, often involving 2 distinct plant hosts. In this case,
the cedar-apple rust fungus infects both junipers (the evergreen
host) and Malus sp.(apple, crabapple). The orange, jelly-like
protrusions on the juniper gall in Figure 1 are called telia,
and contain fungal spores which are splashed to the developing
leaves of apple and crabapple and cause yellow-orange leaf spots.
Apple fruit can also be infected, resulting in raised, blister-like
brown lesions. Spores from infected apple trees are moved to
junipers (again, through wind-driven rain or air currents), and
infect twigs, resulting in galls. The juniper galls (Fig
2) survive for several years, producing orange telia each spring.
A publication on these rust diseases, entitled
Cedar Apple and Related Rusts, can be found at the following
This disease is a concern to commercial fruit growers,
because it can cause blemishes on apples. On the juniper evergreen
host, the disease causes little damage and we don't recommend
any chemical treatments.
Figure 1 courtesy of Ohio State University
Figure 2 courtesy of Peggy Sellers
Fig. 2 Cedar apple rust gall on juniper without spore horn