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Variegated seedling’s sensitivity to full sun

June 30, 2018 tarzan Comments 0 Comment

Scorching sun

At first,leaves were not damaged at all.

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.

Shaded leaves

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.

Fully exposed leaves are damaged the most

Second seedling also has a lot of full sun related damage

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.

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Borinda fungosa winter damage 2016/2017

May 4, 2017 tarzan Comments 6 comments

This winter was quite brutal. Temperatures did not plunge lower than normal, but it got cold enough for the soil to completely freeze down to 0.5m and even deeper. With no snow cover to protect the delicate Borinda leaves, it stood little chance to survive the winter.

The cause

During early winter, there was no visible damage on any of my bamboos, even Borinda fungosa (gaolinensis?) fared much better than I expected. But then came a period when we received no snow, only freezing temperatures that remained below freezing even during the day. Combined with cold north eastern winds, soil cooled off considerably and it froze much deeper than usual. It remained frozen for quite some time, even when temperatures rose above freezing.

The damage

When temperatures got back to normal and after some “warm” rain, leaves lost their green color and it became evident that bamboo ended up completely top killed. Culms were all noticeably bleached, green culms had the darker green, somewhat watery appearance. At that point, I was sorry I didn’t tarp the bamboo and try my best to protect it. It all seems now, that no protection could have save it this winter – the weather was just too much for a marginal bamboo like Borinda to survive intact.

The awakening

There is still some life in it... — There is still some life in it…

In early spring, we’ve had a period of extremely warm weather which had awaken all the bamboos, including the badly damaged Borinda fungosa. I have completely removed the dried out culms and I soon noticed a couple of survival shoots, pushing out from the base of dead culms. Until now, there are no regular shoots that would prove that the bamboo is going to recover. I hope there are healthy rhizomes with undamaged rhizome buds below ground. Usually the first shoots appeared around mid May, hopefully they will push out this year as well.

The conclusion

Some small survival shoots started to emerge

Borinda fungosa I’ve been growing from seed for 6 years somehow managed to thrive in this marginal climate. It got damaged during the winter and didn’t like the heat in the summer, but it managed to grow and upsize into a very decent bamboo. This winter was not typical for us. At least not statistically. It’s sad that the same climate pattern started to repeat itself almost every year. Almost no winter precipitation, cool northern wind and sunny weather can dry out even more winter hardy bamboos. As if the winter was not bad enough, we were recently hit by a nasty late spring freeze. My Borinda doesn’t have the best growing conditions in my garden. It may perish in a year or two even if it survived this winter.

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Late snow in the end of April

April 28, 2016 tarzan Comments 0 Comment

Large Moso shoots when it started to snow.

After several weeks of extremely nice and warm weather, polar blast brought much lower temperatures and a ‘shipment’ of heavy wet snow. Most of bamboos already started shooting some time ago, trees are all leafed-out and most of the fruits have already flowered. The day started warm with strong southern wind, but the wind direction changed instantly, heavy low altitude black clouds appeared temperature dropped from around 15°C to just a bit above freezing. When it darkened in the middle of the day, thunderstorm brought sleet and first half melted snow which instantly started to pile up on plants, even if the soil remained warm enough to melt it.
It snowed for the rest of the day and by early evening, I could hear distant breaking of tree branches. Luckily it only snowed for a couple more hours and stopped completely by the end of the day. Total amount of snow was around 15cm. Considering the fact that a lot of it melted, because of nicely warmed ground, there might have been more on the completely flattened bamboo.

Only an inch of wet snow flattened Spectabilis to the ground.

Like I already mentioned, most of my bamboos already started shooting, especially early shooters like Fargesia sp. ‘Rufa’ and Phyllostachys edulis ‘Moso’. These two started shooting early this year and many smaller shoots already started poking over the canopy of last year’s culms. All those shoots were not nearly hardened enough to handle the weight of heavy snow alone, not to mention the weight of whole bamboo flattened to the ground. Large Moso shoots have been growing on the northern side of the older clumps and that’s what saved them from breakage – bamboo grew more leaves towards south and the culms always fall down into south-eastern direction.

Here's how the Phyllostachys aureosulcata 'Spectabilis' culms look like in the snow. — Here’s how the *Phyllostachys aureosulcata* ‘Spectabilis’ culms look like in the snow.

Phyllostachys aureosulcata ‘Spectabilis’ was lucky to have started growing the shoots slowly. The largest shoots were pushed towards the ground by the weight of the culms, but so far, there’s no visible damage, even if they point into different direction. Other bamboos were only slightly damaged, because new branches already started to grow, shoots were either too small or not existent.

When the snow finally melted, most of the shoots that were bent to the ground recovered. Some of them snapped and died off, but most of them recovered with culm deformation which resembles genuflection, often seen on P. aureosulcata.