With the coldest air in several years moving into the area soon, I wanted to take a quick survey of the bamboos to see how they've handled the winter so far.
At the time these photos were taken on a mild New Year's Day, the lowest temperature my garden has seen this year has been about 6ºF. Let's see how the bamboos have fared...
For the most part, the larger plants are all looking quite good -- the Phyllostachys I have are pretty cold-hardy, but a few of them are marginal here. In the photo above, Ph. atrovaginata on the left and Ph. aureosulcata on the right are both untouched by winter so far.
Perhaps I should review the stages of temperate bamboo cold damage? Ideally the bamboos will come through the winter undamaged, but the first level of damage is leaf burn:
That's a potted Indocalamus tessellatus that didn't get enough water. Note the light green, grayish color of the burned leaves. Here's the same plant that didn't get as water-stressed:
You can see that there is only a small amount of burn visible.
After leaf burn, the next stage of damage is leaf kill, where all of the leaves die and turn "blonde". You may remember that I saw this a few years back with my Ph. atrovaginata:
Luckily I haven't seen that yet this year, but it may be coming. Even though all of the existing leaves will drop, the leaf buds survive so the culms will leaf out again in the spring. The third level of damage is where the leaf buds are damaged too, resulting in culms that can't re-leaf -- bamboo growers refer to this as "top kill" or "topkill", as nothing above ground is left alive (culms with no leaves will die).
Brad (at Needmore Bamboo) is my bamboo mentor, and he's learned over the years that 5ºF is sort of the critical temperature for many bamboos. When it gets below that mark, damage starts really increasing.
Here's what I've seen so far with my 6ºF temps...
Ph. bissetii looks quite good, with only a few branches showing rolled leaves (a sign of either damage, drought, or both):
Sasa veitchii is supposed to look like this, at its best in the fall and winter:
Sasa tsuboiana fine in ground:
But not so good potted (needs more water):
Sasaella masamuneana 'albostriata' looking perfect:
Phyllostachys nigra, one of the marginal ones in my garden, taking some damage:
That one has been sizing up nicely the last two years, so I'm hoping it won't be topkilled -- but I expect it to be. Sigh.
Right next to it is the also-marginal Semiarundinaria fastuosa 'viridis', looking great so far:
I expect this to take some damage over the next few days too.
Most of the ground cover bamboos I expect to topkill every year, and they usually do:
That's Pleioblastus distichus, and here is Pleio. viridistriatus:
Pleio. fortunei is toast too:
Pleio. humilis is halfway there, probably will be completely fried after this weekend:
I'm not concerned about these getting fried because I'll just mow them in the spring -- they'll come back strong soon after with all fresh growth.
Way in the back of the garden the Ph. rubromarginata (left) and Ph. aureosulcata 'spectabilis' (right) each show some branches with curled leaves:
As with the Ph. bissetii, I don't know if this is damage or just plants that needs more moisture.
I have several Fargesia dracocephala 'rufa' plants, and they all look quite good so far, but that's expected because these are quite cold-hardy:
Then there's this Fargesia that was labeled as a 'rufa' but has never acted like one:
You can see it's taken some damage already. If it topkills I may end up removing it.
Last up are Shibatea kumasaca (left), Hibanobambusa tranquillans 'Shiroshima' directly behind it, and Sasaella bitchuensis (right), plus various potted bamboos in the background:
Still looking good! It's so nice having all of this green around throughout the winter!
That's not every bamboo I have, but it's a good sampling of what I've seen so far. I'll do a follow-up post in about a week, so we can see how everything looks after some negative temps (F).
It's a post I'm not looking forward to.