Variegated seedling’s sensitivity to full sun
June 30, 2018
Shooting season is over and all the new shoots are now fully grown and branched out. At first, there was no issues related to direct sun exposure. I suspect the problem started when the sun position got high enough and its strength became harmful for delicate plants. I observed first signs of leaf damage as soon as the shoots started branching out. Then damage became more and more evident and even the newest leaves immediately got damage, some even before unfolding. Spraying the bamboo with insecticide and fungicide didn’t help much. Leaves were a bit healthier, but that could be just because the leaves started getting less variegated at the same time, changing from completely yellow to yellow with green stripes. Sun is also starting to lose some of it’s strength as days are getting shorter.
At first I wasn’t sure about the exact reason, because I also found spider mites on both variegated bamboos. With time, issue became more and more apparent. The shaded leaves that were hidden inside the bamboo clump became hard to miss- they remained healthy and mostly undamaged. Sadly, both bamboos are placed in full sun which makes them suffer leaf damage during most of the summer. Leaves in the fall should be healthy again. Last year, bamboos were much shorter and received a lot of shade from plants growing around them, this year, they became too tall for that and I’ll be able to see when they stop getting sunburns. The first leaves are also the most delicate. Luckily, most of the leaves that are damaged would fall off eventually before the end of the summer when the plants fully leaf-out.
changing their location
In a year or two, I’ll try to find them a more protected location with more shade. I might even divide them for the first time and try them in “different depths of shade”. Currently, finding them free space is a problem, which I hope I can resolve.
… An update a couple of weeks later…
In just a few weeks, the spot of one seedling got shaded and I successfully removed the mites as well. At the same time, laves started getting more green, just like expected. The shitty humid weather held on during most of early summer and in mid July, seedlings looked better. They started growing branches and started to look much, much better.
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.