<< Since you asked, I thought I would give you a few bullets on bamboo at my place this winter (dare I say spring yet). The forecast (March 24) is for more snow and last night it was down to 14 F.
1. I did a study several winters ago comparing actual exposed temperature against the official temperature which is shaded from radiation cooling. The night time temperatures averaged 5 to as much as 10 degrees colder in the open. With the 5 degrees for the colder, 15 to 20 degree nights. So, what does this mean to me the gardener? Plant zones and temperature ratings for plants are given by the minimum temperature. But, are these actual measured temperatures at the plant or official weather station temperatures? For back yard gardens and small plantings we are really interested in micro-climates at the location we are planting our bamboo. This can vary by many degrees, particularly around buildings. So, the best we can hope is that the catalog listings of minimum temperatures are accurate. Then we should adjust our expectation of minimum temperatures for the exact location. This would mean reducing an exposed location by 5 to 10 degrees from the “official” minimum temperature for the area. Of course nature is never too precise, and there are several levels of loss due to low temperatures: loss of leaves, loss of culm, and finally loss of the whole plant, rhizomes.
2. This past winter my lowest, shaded, temperature was 4 degrees on a clear night, and this is the lowest I have seen in 15 years. I am in zone 7a which is supposed to have a minimum temperature of between 0 and 5. Pretty accurate.
3. For the first time every bamboo on my property has their leaves desiccated; yes even the rock hardy, Phyllostachys parvifolia. Hopefully they will re-leaf in the spring. However, I plan to cut to the ground the Sasa palmata f. nebulosa, Indocalamus solidas, Hibanobambusa tranquillans ‘Shiroshima’, and Pleioblastus viridistriatus ‘Chrysophylla’ . I hope this is not too drastic, but I would like new fresh leaves for the summer. They are all spreading, and so a cut back in growth would also be desirable.
4. The Sasa palmata f. nebulosa, Indocalamus solidas, and Pleioblastus viridi- striatus ‘Chrysophylla’ are absolutely beautiful with their solid pale tan leaves. What a treat, since they are right at the end of the driveway and seen every time I go by.
5. Something very unusual, at least for me, has happened to the Fargesia group here at my home. They are all standing straight and tall, except perhaps the F. rufa which has an ever so slight curve, no whereas near a bow as usual. They also all have dried leaves. The standing tall looks great in the garden where I have them. However, I have on my list of winter things to do to prune back the clumps to provide room for the neighboring plants which are getting crowded out. Now that they are straight, there is no problem. I suppose I should plan ahead and assume they will again be bowing when the spring comes and things warm up. The Fargesia which are so affected are: F. rufa; F. rufa, narrow leaved; F. robusta; F. nitida ‘Jiuzhaigou’; and F. denudata. The narrow leaved version of rufa is, right now, much straighter than the usual rufa. The first time I have noticed any difference between the two.
6. I am getting older and weaker, and so we are cutting back on the Phyllostachys collection. Quite a shame since to me they are the “real” bamboo. There is nothing like walking through a grove. If anyone wants rhizomes of P. aureosulcata ‘Aureocaulis’, please give me a call. The bed is approximately 48 by 11 feet.
7. Elizabeth and I always enjoy the bamboo group. So, if you all would like to come for a visit this spring/summer we would be honored. >>