Possible culm coloration on variegated Phyllostachys arcana seedling
April 24, 2018
Three year old seedlings of Phyllostachys arcana ‘Luteosulcata’ finally got culms that are up to pencil diameter. Until now, it was impossible to see any culm coloration, except for the rough estimation of culm color. First shoots finally started to show the exposed culms above their culm sheaths and it seems that one of the seedlings got culm variegation that is similar to that expressed on its leaves.
I already wrote about how different the culm color of the seedlings is, so this is an update on that topic.
I also wrote a lot about the leaf variegation, growing these seedlings from seeds and similar. If interested, you can look it up using search option.
Culm color expectations based on last year
After slow start with many setbacks, seedlings started extremely well this spring and took off. I expected culms of three variegated seedlings to have different shades of green, but I never expected culm variegation. The first seedling shows the most leaf variegation and has lime green, almost yellow culm color that eventually fades to light yellow with orange hue. It easily gets sunburn and the color of sun exposed culms is light red. Second most variegated seedling with a bit darker green culms sunburns to dark red color. Third seedling did not manage to push out any shoots this year. Deer devoured it completely last fall and it only managed to push out survival shoots and branches. It has culms that are even darker green than the second seedling, but still less dark than regular non-variegated seedlings.
A bit about sunburn
Every seedling of Phyllostachys arcana ‘Luteosulcata’ got sunburn when exposed to bright light in a sunny location. Even culms that were not directly exposed to the sun darkened-up. Seedlings got purple color, which combined with regular green culm color and appeared dark brown. Variegated seedlings with less chlorophyll turned bright red with more or less dark tone, depending on the seedling. It will be interesting to see, how long the color of sunburn remains apparent on the colored culms. Non-variegated seedlings got light brown in their second year as the green started to fade into yellow. Variegated parts will most likely have darker sunburn but I don’t think it will easily visible feature because sun tanned color is too dark and intensive. I guess we will see more about it next year.
Culm variegation on seedling #2
Second seedling had shown no culm variegation last year, because all the schoots were toothpick diameter or smaller. I pampered variegated seedlings way too long, keeping them inside during the winter – big mistake. This year, when they had a chance to go through winter dormancy, they started growing like a Phyllostachys should grow! When I first saw almost undetectable striping on the freshly exposed culms, I thought it was lack of wax or shade. In the following days it became more and more apparent and it darkened with passing days – same thing happens with leaf variegation. Culms are still pretty small, so it might take a few years before I can get a feeling about how the mature culms will look like, but we’re getting there! It will be interesting to see how the effect of sunburn on the culm striping.
Many of you already know about the leaf variegation of all three seedlings I’ve grown from seeds. They start as very pale lime green or even yellow leaf which eventually starts showing darker stripes and it turns darker green. The ‘transformation’ happens in about a week or two. After that, leaf starts maturing and it gets darker green but the variegation remains. Some of the leaves are completely pale and appear yellow even after a few weeks. Usually leaves like that get damaged easily (I suspect bright sun related burn) and partly or completely dry up. Usually these are the first leaves that appear on new shoots, so they end up falling down anyway. As the branches or shoots age, there are usually more and more darker green leaves. I have to admit, I want to know how it would look like on a mature grove during the shooting, soon after and right before winter. It may change color a little bit during the seasons. Hopefully we will see.
Early shooting of Phyllostachys arcana seedlings
March 21, 2018
Cold winter is ending
Winter is not quite over, with morning low temperatures down at -5°C and I saw the first shoots on all of my Phyllostachys arcana ‘Luteosulcata’ seedlings. I planted them into a raised bed and covered with a transparent PVC cover so I could protect it from freezing temperatures during the winter. When the temperature dropped too much, I piled up snow on top to insulate the bed as much as possible. It now seems it worked perfectly. During the winter, the soil got frozen on several occasions, but it didn’t seem to bother the seedlings much. They were showing first signs of dehydration, yet none of them shows any signs of frost related damage. In fact, they look way better than they did when I was overwintering them inside. They struggled each and every winter, except their first year as tiny seedlings.
First shoots in mid March
None of the bamboos started shooting this year yet, not even the fastest shooter I have, Fargesia Rufa. I was pleasantly surprised to see the first shoots on arcana seedlings, even though they were protected. The shoots are small and there’s no way to tell what kind of upsize is to be expected, but they are here! It could be, that they started during the fall and had now decided to continue with their growth. I doubt it, because all the autumn shoots were whip shoots and these are regular spring shoots (still juvenile). I guess we’ll have to wait and see.
Hoping to see an upsize
So far, none of the Phyllostachys arcana ‘Luteosulcata’ seedlings had shown their parent’s striped culms. I have two vigorous unvariegated seedlings that are going to become at least pencil size thick this year. I’m sure if there is any culm variegation, they should start showing it by now. There are also 3 variegated seedlings that will be interesting to see developing. They are showing quite a lot of differences, even at their current juvenile phase. I’m very interested to see their culms color. It now seems that one of them is going to have yellow-ish culms with an orange tan. I have yet to see if the orange colour persists with age, or is it just a sunburn pigmentation that will eventually fade out.
A word about first overwintering of variegated seedlings
March 10, 2018
Winter is finally coming to an end. Days are getting longer, snow has almost melted and mild spring-like temperatures are on our way. This winter was quite cold with temperatures down to -16°C and strong north-eastern wind that emphasized the windchill index. Luckily, we’ve also had quite a large amount of snow during the cold weather. It was not hard to protect bamboos using snow this year, so I expect minimal damage on my larger bamboos, moderate damage on my Moso seedling and no damage on my Phyllostachys arcana seedlings.
I can only hope we don’t get hit by severe freeze in late spring like we did the last few years. It did not affect the bamboo much, so I’m more worried about other plants and fruits around the garden.
I’m keeping my variegated seedlings in a raised bed. To keep the bamboos protected, I covered the whole thing with a PVC tunnel. It did OK throughout the mild first part of winter, but as it got really cold, I’m not sure the seedlings would be able to survive without better protection. Lucky for us, the polar blast brought some snow, so I was able to pile it up around the raised bed. There was enough snow to cover the bed completely. Later, we’ve got quite a lot more snow and tunnel finally collapsed under thick snow cover. When the worst was over, I removed the snow and found the seedlings completely unharmed. They were in better shape than I hoped they would be. I hope to see a decent upsize this spring. Last year, there were hardly any new shoots, all of them seemed to be survival shoots. They managed to grow long rhizomes in all directions, though, so I expect them to upsize… eventually.
Protecting bamboo during the winter
March 10, 2018
Most of temperate bamboos are quite cold hardy, but there are exceptions and every plant’s cold hardiness has its limits. To prevent damage during the cold months of winter, it’s often best to offer your plants at least some protection to prevent loosing your bamboo.
Most common causes of winter damage
Beside the cold itself, sometimes there are other causes of winter damage. In late fall, bamboos go through a preparation period in which their cold hardiness improves considerably. Their growth and transpiration halts to a minimum, some can even shed some of their leaves. When soil is cold, sometimes even frozen, water mobility from roots towards the leaves is extremely difficult process which can even completely stop if the soil or any part of bamboo culm gets completely frozen. At that point, each additional leaf that requires water, means that the plant loses more water than it can replenish. It is also good Idea to mulch the soil around the bamboo with layer of dry leaves, grass or wood shavings. Mulch does attract rodents, which can sometimes cause more damage than the mulch prevents. If you fertilize in late autumn, there is a possibility that bamboo fails to enter the winter preparation and continues to actively grow. During growth it’s much more delicate and can be damaged by either drought, heat or cold. Plants that were already stressed during previous growing season are often more prone to cold damage.
How cold is too cold?
There’s no answer to that one. Cold damages plants, but it usually doesn’t “work” alone. If it’s cold and the weather is overcast or if there’s fog and no wind, there will be much less damage, compared to clear sunny windy and frigid day. Wind can dry out even the most prepared leaves that are coated with thick layer of wax. Sun warms up the dark green foliage that heats up readily, transpiration rate goes up and the roots can’t supply enough water. When you combine all three, cold, sun and wind, the effect is by far the worst. I’ve lost several bamboos in those conditions.
Piled-up snow – best winter protection
When snow falls over bamboo, it will easily bend and soon, snow covers the bamboo completely. That is bamboo’s natural defense against winter extremes and it works extremely well. If there is at least some snow before the cold hits, it’s best you use it! By tarping the bamboo down to the ground, it is easier to cover it with snow. I usually just shovel up a pile of snow over it, and hope enough snow falls before the bitter cold arrives. Tarping bamboo to the ground is necessary when the plant gets larger, but usually gets impossible as the plant matures. Snow covered bamboo makes the air around bamboo leaves warmer than the air above, regulates moisture and prevents desiccation. It is also dark and keeps only minimal transpiration.
All the snow covered bamboos survived the cold blast completely intact. Soil did not freeze under snow insulation and my protected bamboos only suffered minor culm and branch breakage. The much taller and robust bamboo culms that remained exposed got damaged. My Moso seedling that got drought and heat stressed during the summer is going to show substantial winter damage. Tender Phyllostachys aurea is fried up to 50% and Phyllostachys aureosulcata ‘Spectabilis’ (Lamatempel) with no damage whatsoever. All my smaller other bamboos got protected by themselves – snow laid them flat and since the snow cover got thick enough, they remained safe during the severe winter weather with temperatures down to -16°C and powerful dry wind.