honeysuckle. I cannot find info on the issue/treatment. A friend suggested I
email you after reading the LVRJ column.
A. Thanks for the pictures but they were not very helpfulwithout more information. Let me tell you what I know about these plants and
maybe that can help.
Both of these plants grow well
in our climate in a mixed, non-desert landscape. They are not desert adapted or
desert plants so they will not perform well with rock mulch.
Over time, they
will perform better using wood mulch on the surface of the soil.
They should be irrigated at the
same time as other non-desert plants. They should be on an irrigation valve
that provides water as frequently as other nondesert trees and shrubs.
least one fertilizer application each year in the spring or late winter. You
can apply these spring fertilizers into March. Any general landscape, tree and
shrub fertilizer will be good.
Pyracantha occasionally developsyellowing due to iron chlorosis so an application of EDDHA iron chelate to the
soil at the same time as the fertilizer would be advised. Apply both within a
foot of drip emitters on top of the soil. The iron chelate needs to be covered
with mulch.
Pyracantha has a history of
borer problems, particularly if it is planted in a southern or westerly
exposure in rock mulch with lots of heat and intense sunlight. Borers can be active
in the plants and the plant can still appear healthy for one or two seasons.
After a season or two of borer
attacks branches turn brown and begin to die back. They normally die back to
where the borer damage while the rest of the undamaged plant below this remains
green. Prune these dead branches out and let the plant regrow from these areas.
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| Pictures from reader |
Because of the dead branches,
the interior wood and trunk will receive intense sunlight. This intense
sunlight increases the chance of sunburn to larger limbs and the trunk. This sunburn
damage attracts boring insects (borers) to those locations.
.JPG) |
| Borer damage in purple leaf plum |
For this reason, shade from the
canopy on the interior wood of the plant is extremely important. Many woody
plants in the rose family, which includes Pyracantha, are subject to damage
from intense sunlight due to their thin outer bark.
Most of our fruit trees are
also in the rose family and are subject to sun damage and borer
problems. Pruning should be pruned to
maintain a moderately dense canopy. A canopy which is not so open provides filtered
sunlight to the interior of the plant and reduces sun damage. You don’t want it
pitch black inside the canopy but you do want filtered light, not intense
sunlight, for any length of time.
Honeysuckle is a good vine to
use here. However, it tends to get woody at the bottom as it gets older. This
woodiness at the base can be managed by pruning it correctly. Woodiness at the
base is promoted when the vine is pruned only at the top. Several years of
pruning the top results in an unattractive plant that is mostly wood without much
foliage.
When pruning this plant this
winter, instead focus pruning efforts on the area close to the soil surface.
Find large stems originating from this area and remove one third of this older
wood close to the ground. This removes a lot of plant material from the vine
but promotes new growth from the pruned stems.
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| Limb dieback of peach due to borers |
These types of pruning cuts
encourage new growth from the base of the plant. Next winter remove one third
more at the same location and you should be back on track and reversing the
aging of this plant, making it more juvenile. Focus your pruning efforts closer
to the ground.