Wednesday, January 20, 2010


Damage to Calamondin Orange and Variegated Oleander from 20 degrees in Austin.
Leaves will drop and plants will be pruned back to live wood for spring recovery.

To us gardeners in central Texas, despair generally follows a hard freeze when the first effects on our beloved plants are noted, but deeper despair follows a week or two later when the real damage is finally revealed. Some effects may take a month or more to become noticeable. Before despair leads to depression, let’s look at the bright side.

Those dead looking plants most likely aren’t really dead – they’re just playing “possum” and waiting for spring conditions to revive. It’s their natural defense mechanism to shut down under such conditions.

   With shrubs, use the fingernail test – scratch progressively downward until dead brown tissue becomes green live tissue. Then they can be pruned back to just above that point for regeneration. Although we are advised not to prune back more than one third of a shrub at any time, hard pruning beyond that level may be required to remove dead wood. With perennials, cutting back an inch or two from ground level will help regenerate them in spring. Root freezing is their worst fate, not death of foliage. In the case of Yuccas, Agaves, they most likely will send up pups in spring from the surviving base if top foliage dies, unless the entire plant froze, roots and all from soil being too moist.
The deep freeze kills many of the harmful insects that invade and harm our gardens so it’s natures way of keeping everything in balance. Dead growth should be removed however to prevent the introduction of disease organisms in decaying matter.

The occasional loss of some of our plants provides the opportunity to rethink our garden design and content. It is good to try different plants in different growing seasons. The garden becomes a research laboratory of sorts. Perhaps the loss of some plants has provided some additional space to do just that. Perhaps there are lessons learned from which we benefit. For example, my large 18”x24”ceramic pot that contained hardy water lilies didn’t survive whereas the lilies did! I forgot about the expansion of water as it becomes ice – duh!  So, my lesson learned is to use a galvanized metal container for this water lily garden in the future.

It also pays to keep records of plant performance under different stressful conditions, a journal or sort to refer to if those conditions occur again. Note micro-environments that provided just enough protection to help a plant survive beyond it’s normal expectation. Also note those plants that were totally unaffected by the sub-20 degree cold and use these as base plants (the bones) for your garden.

Often, conditions other than the cold cause death to plants. I had a native Claret Cup Cactus croak (say that fast 10 times) that is supposed to be hardy to 20 but cacti can only handle lower temps when the ground is dry – so I knew what did it in and will try to provide a dryer growing condition for similar plants. Let’s face it. We don’t get a lot of rain per year in our area, but when it rains, it rains, and often at the worst possible time – just before a freeze which can be a much deadlier combination that just the freezing temperature.

The most agonizing thing for a gardener is the long wait to see if a plant that has died back to the ground will emerge as a healthy plant in spring. This doesn’t always happen. Often disease organisms attack a weakened plant when in dormancy. If a plant doesn’t emerge at an expected time in spring, it is best to dig and examine roots for any signs of life, buds, live roots, etc. Any dead portions should be trimmed off before replanting. Do not fertilize any plants in spring until healthy shoots emerge and begin to mature, as without leaves for photosynthesis, chemical fertilizers can become toxic to the plant. If shrubs are just tip burned from a freeze, don’t trim back until spring as that would just encourage new vulnerable growth to emerge prematurely.

Rather than seeing the damage a hard freeze brings to your ornamental garden, look at the bright side. If nothing else, you can look forward to seeing the resurrection of life anew in spring as you stroll through your yard. Also see the opportunity to improve your garden from the previous year based on what you have learned from this winter. Don’t jump the gun though but wait for the right time to begin that renewal. You can cultivate soil, build up and enrich your beds, do any additional hardscaping you want to do to your garden infrastructure, research new planting possibilities for the coming year while waiting for any danger of frost and freeze to pass, generally around April 1st in central Texas. This way, you will be raring and prepared to jump into another wonderful year of gardening pleasure.

So don't despair.  It is psychologically tough for us as gardeners to see what old man winter does to our gardens, but it could be worse - you could be the poor plant out there  trying to survive it! 

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