Q. I planted six Podocarpus (Fern Pine) in March, three by the north
wall and three by the south wall. Now the three on the north wall have leaves
that are turning brown. The three on the south wall are fine. I just didn’t
realize that the trees would get this much sunscald. Any suggestions on what I can do, besides give
them macronutrients and hope for the sun to change course?
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| Readers podocarpus with leaf scorch |
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| Podocarpus showing very little podocarpus |
A. Judging from the picture you sent showing the leaves
turning brown, I really do not think it’s going to be a continuing problem for
you on the north wall once this is corrected. The south wall will be more of a
challenge. I do not think this is sunscald but it is either a lack of water,
watering too often or a lack of soil improvement at the time of planting.
turning brown, I really do not think it’s going to be a continuing problem for
you on the north wall once this is corrected. The south wall will be more of a
challenge. I do not think this is sunscald but it is either a lack of water,
watering too often or a lack of soil improvement at the time of planting.
Since
the problem you are having seems to be on the north side and not the south
side, I might guess that you are keeping the soil too wet on the north side or
they are not getting water.
the problem you are having seems to be on the north side and not the south
side, I might guess that you are keeping the soil too wet on the north side or
they are not getting water.
The
north side and the south side are radically different micro-environments. It is
much hotter on the south side than the north side. This means plants on the
north side should be watered less often than plants on the south side.
north side and the south side are radically different micro-environments. It is
much hotter on the south side than the north side. This means plants on the
north side should be watered less often than plants on the south side.
Notice
that I said less often. The plants on both sides should receive the same amount
of water but the difference should be in how often they are watered. To
accommodate this difference in frequency of irrigation, plants on the north
side should be on a different valve or circuit than plants on the south side.
that I said less often. The plants on both sides should receive the same amount
of water but the difference should be in how often they are watered. To
accommodate this difference in frequency of irrigation, plants on the north
side should be on a different valve or circuit than plants on the south side.
In the
first picture it looks like you have rock for surface mulch. That will be a
mistake for these plants in the future. It will be okay for a year or two but
you should consider changing this out to wood mulch instead of rock.
first picture it looks like you have rock for surface mulch. That will be a
mistake for these plants in the future. It will be okay for a year or two but
you should consider changing this out to wood mulch instead of rock.
If you
are going to have problems with this plant, it will be on the south side. These
plants will tolerate a little bit of drought and infrequent watering so treat
them like landscape trees and shrubs with deep but infrequent waterings.
are going to have problems with this plant, it will be on the south side. These
plants will tolerate a little bit of drought and infrequent watering so treat
them like landscape trees and shrubs with deep but infrequent waterings.
In other
words, do not water them daily. At these temperatures, as long as you have good
drainage, twice a week with about 10 gallons for each plant should be adequate
on the south side if they are on drip emitters.
words, do not water them daily. At these temperatures, as long as you have good
drainage, twice a week with about 10 gallons for each plant should be adequate
on the south side if they are on drip emitters.
On the
north side, once a week would be adequate. If they are on drip emitters, they
should have an emitter on each side of the plant. Put the emitters towards the
front of the plant as far from the foundation as possible.
north side, once a week would be adequate. If they are on drip emitters, they
should have an emitter on each side of the plant. Put the emitters towards the
front of the plant as far from the foundation as possible.
There is
a lot of calcium sulfate or gypsum in our soils. Adding water to soils high in
calcium sulfate can increase corrosion on concrete.
a lot of calcium sulfate or gypsum in our soils. Adding water to soils high in
calcium sulfate can increase corrosion on concrete.
After
mid-October you can cut your watering to once a week or longer but the same
amount of water. In mid-December you can water these about every 10 days.
mid-October you can cut your watering to once a week or longer but the same
amount of water. In mid-December you can water these about every 10 days.
These
are evergreen plants so the damage will not disappear until new growth covers
the damage to the leaves.
are evergreen plants so the damage will not disappear until new growth covers
the damage to the leaves.
I'm going to say too much water also. I've seen that look before, and the tree showed sprouts of new life kept popping out, but it took a sudden turn and went full brown about a month or two later. The situation was impervious clay and an every other day watering schedule. They were basically in a swamp environment.
Thank you for the information…my question is should I just leave the brown leaves there on the hedges and let the new growth take over?
The best place to grow them are in the north or east sides of the building. They will struggle in a south or westerly exposure in full sun particularly if there surrounded by rock mulch on the surface of the soil. They will grow much better if the soil is more organic and covered in woodchips. If there is rock present I would rake it back about 3 feet from the trunk, put a layer of compost on the soil surface, water it in and then cover the soil with a 3 inch layer of woodchips.
When can I fertilize my newly planted potocarpus Maki, they are 3 ft tall