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Greenhouse freeze damage |
The California Central Valley had an unusual
week of sub-freezing temperatures in 2007. The daytime temperatures
were in the 40s to 50. But at night it dipped to the mid 20s. On
several nights I recorded 22 degrees F.
My greenhouses are not heated. They are technically called "cold
frames." But the daytime heat gain is stored in the plants soil and
water. So the night time drops were buffered somewhat and the plants
were not exposed to continuous 22 degree lows. To help them survive
they were watered during the warm part of the day. |
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(Below) notice how this Bridgeseii had the tip frost burned yet by
March had sprouted an offset tip. |
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(right) Even though this looks bad you should not cut it off during
the winter. Wait until spring when the plant's immune system wakes
up.
Tip damaged plants such as this one make excellent stock plants
since they will offset new tips that can be harvested & rooted into
new plants. |
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| These are finger sized tips growing off an old log.
Their small size made them the most vulnerable of all the
San Pedro in the growing house. They were the only ones to
suffer burned tips. At first I thought they would die and
rot off but instead started to grow again. |
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(below) Don't cut frost damaged tips unless you have to. The plant's immune system is
weak during the dormant (winter) period. Cutting a tip can lead to
infection & rot. Having said that, I did have to cut one Bridgeseii
tip off because the dead tip was spreading rot to the column below
it. Fortunately it healed up fine. |
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