Evaluating Winter's Plant Damage

Agave victoria-reginae

 

When you over winter several hundred cacti and other succulents in three wooden boxes, covered by plastic, and heated with small electric heaters, there is bound to be problems.  The potential "big" problem is a loss of electricity during a severe cold period.  Without the heaters, temperatures in the over wintering boxes would drop below freezing in 4 to 6 hours.  There were no power outages this winter and no heater failures.  Most of the plants came through the winter in good conditions, but there were a few sad exceptions.  Perhaps the most notable, and for me the saddest, was my seed grown, 19 year old, Agave Victoria-reginae. 

 

When I first saw it I wasn't sure what had

happened.  This was not low temperature damage.  Why a band of damaged tissue in the center of the leaves?  It took me a day or two to figure out what had happened. 

Notice how the leaves are all in an upright position. This is due to the plant being very dry.  Because the winter was so consistently cold, I had little opportunity to open the over wintering boxes and give the plants any water.  It reacted to the lack of water by pulling its leaves upright to protect the terminal growth and further reduce water loss.  This is a normal reaction.  But what it did is expose the undersides of the leaves to strong, direct sunlight (remember in winter the sun is low in the sky), and basically, sunburn the leaves.  The undersides of the leaves are not normally exposed to direct sun.  They weren't acclimated to direct sun, and when exposed they were damaged.  As far as the plant is concerned, it is fine.  In nature it would continue growing and eventually flower and set seed, its primary function.  But in terms of a nice show plant, it is ruined.  I probably should have anticipated this, but I didn't.  I was concerned with just keeping the plants warm, forgetting about what the extended lack of water might cause.  You live and learn, but this was a tough lesson. 

 



 

Revisiting the Red Titanopsis

 

Titanopsis  calcarea  -   The Red One

 

My blog of May 21, 2013 was about two titanopsis seedlings I found with red coloration in their leaves.  The seed came from my own plants but the pollination was uncontrolled.  Basically, one of my titanopsis plants formed a fruit with no pollination help from me.  I have no idea what the father plant was, but it was likely another titanopsis.  I collected the fruit and planted the seed.  This resulted in about a group of seedlings, including several that were a reddish color.  I potted them up, placing the two red seedlings in a single pot.  It was my guess that the red color came from stress, because I placed the original pot of seedlings in my over-wintering frames and they were in a lot of sun and didn't get watered regularly. 

 

After I rediscovered them last spring I gave them better care, basically more water, and they grew well over the summer.  They went back into the over-wintering frames for the past winter.  Once again this spring the red color is still there and the plant is quite attractive.  This could still be due to stress as life in the over-wintering frames this past winter was very dry, but with a lot of sun.  It's a pretty Titanopsis calcarea and I thought I would show it off again.  Perhaps I can do some pollinating when it flowers this year and see if I can find something interesting in the resulting seedlings.  

 

 



After a Long Winter Rest

 

Prepodesma  orpenii

 

The former Aloinopsis orpenii, now Prepodesma orpenii, has spent a long, cold winter in my over-wintering heated frames.  The electric heaters did their job and kept the minimum temperature in the 40-43 F. ( 4.5-6.0 C) range, but because of the consistently cold weather, I was unable to open the frames on a regular basis and all the plants received very little water and spent a very dry winter.  Most cacti, and other succulents handle, maybe even prefer, a dry winter, but small plants, and winter flowering plants, need a little water over the winter.  I usually give Prepodesma orpenii some water beginning in mid to late February, but this year that was not possible.  Nevertheless, it has come through the winter ok, and is now budding up and preparing to flower.  These little mesembs are tough indeed.