|
Spring-flowering bulbs generally need well-drained soil
and do best under deciduous trees. They will be rather
short-lived under evergreens. Large bulbs, such as tulips and
daffodils, should be planted 6 to 8 inches deep. Small bulbs are
planted about 4 inches deep. The rule of thumb is to plant bulbs
at a depth equal to two to three times the height of the bulb.
Plant the bulb with the point up. It is a good idea to map the
location, or place a colored golf tee above the bulb. Then mulch
with 3 to 4 inches of mulch, and water thoroughly after
planting.
Tree decline
When an entire tree looks like it is dying, the injury,
disease or insect logically must be affecting the trunk or the
roots. These areas would cut off the water supply to the entire
tree. Look at the entire tree and compare it with nearby trees.
Also consider when the problem started and what changed on the
site about that same time. Healthy trees don't suddenly die
because they are old.
Many below-ground reasons may cause tree decline. Drought,
flooding, compaction of the root zone, poor soils, planting too
deeply, inadequate space for roots and many other things could
be involved. We have definitely had more than our share of
stressful weather the past few years, with alternating flooding
and drought.
Often, diagnosing such a problem is a process of elimination.
One of the possibilities more difficult to eliminate is root
rot. Most gardeners believe that they cannot possibly know the
health of a mature tree's roots.
Cankers on the stems, stem tip dieback, off-color foliage,
early fall color and early defoliation are clues that a tree may
be stressed by underground causes.
[to top of second column] |
To detect the wood rots and root rots, look for mushroom-like
fungi growing at the base of the tree or shrub. In wood rot
fungi, the conks (also called shelf fungi or fruiting bodies)
may be found growing on the trunk or main branches. These are
signs of the disease. The actual fungus is probably growing in
or on the roots, or inside the wood.
One of the most common examples is Ganoderma root rot, which
produces a shelf-type of fungal structure at the base of many trees,
especially honeylocust. The structure is reddish-brown and appears
to have been varnished. Its presence indicates invasion by a root
rot. Other fungi may indicate wood rots.
Wet weather often triggers the formation of these structures.
They could easily be confused with fungi growing on dead organic
debris near a tree. If, however, they are growing from the tree
itself, they are excellent signs of wood rot or root rot.
No chemicals help a tree in decline. Use approved cultural
practices, such as proper watering and fertilizing to improve
vitality. Cut out dead branches in the dormant season, fertilize in
late fall or early spring, and keep traffic off the root system. For
very old or large trees, fertilization and watering may have no
benefit, but these practices sometimes help the tree survive for
years.
[By
JOHN FULTON,
University of Illinois Extension] |
