Although the garden isn't quite a wasteland, the mixture of hope, disappointment, pathos and satisfaction really does make this month an emotional whirlwind. The latest: a new and formerly healthy A. sinopurpurescens graft has been killed, the understock bark stripped off on the low half inch completely, all the way to under the soil line. What could be doing this, mice? The bark was pretty tough, platanoides I suppose. Perhaps 20 other nice 1 year seedlings have received a similar treatment although here the rings are only maybe 5 mm wide. The damage done in the seedbeds by mice is becoming apparent, very little activity. I thought surely they couldn't have eaten everything. I leave the seed trays outside raised on palettes and netted against birds (and cats) but I don't think anything keeps a determined mouse out. Really disappointing, I had a lot of great seed this year, both my own and from other sources. Feh. Losses in overwintering seedlings is around 40% including it seems most of the nice ones. That really pretty variegated pink I posted last fall looks like it's on the casualty list. A. mandshuricum, which was developing really nicely, has died off by half, just like that. The main part of the 3m tree just didn't leaf out. A. serrulatum (olivarianum ssp formosanum if you prefer) has lost most of the branches to pseudomonas. Not a big plant but it had seemed healthy; I think the drought last year weakened it too much. It may live. On the other hand, A. diabolicum is flowering again, the second year in a row! It looks like erianthum will survive after all in its pot. A. schneiderianum has miraculously come back and seems like it will recover from the bark problems in situ. It's sunny, the grass is green, the maples are gorgeous, and with each new seedling or young graft that leafs out I breath a sigh of relief. Blue skies today, but a hard frost announced for tonight... ;) -E
Probably voles, there's been very high numbers across N Europe, following on from the two very snowy winters 2009/10 and 2010/11 (the snow protects them from predators like owls).
Yes. voles indeed. I (wrongly) group them with mice. They do more damage, and we have had periods where they are quite visible in the lawns. Curiously just now there don't seem to be as many where the grass is cut short anyway. The cat eats many, but I suppose she just can't keep up. Interesting about the high numbers. I've never had the seed beds disturbed before, or seen this kind of damage.
Emery, I feel for you. I have lost (am in the process of losing) 99% of last year's palmatum seedlings this winter/spring to what I believe are vine weevil grubs. As well as all the soft roots, they eat all of the epidermis and root cambium off the woody roots from underground to just above the soil line. Most of them are still leafing out normally so I have removed all the soil and planted them deep in fresh potting mix, in the hope that some of them might root from the healthy bark that would otherwise be well above the soil line. Here is a picture of what the damage looks like, this is a two year old seedling but the worst affected have been the smaller one-year seedlings.
Yikes Maf. Really very sorry to hear about your issues. That actually looks a lot like the damage on the sinopurpurescens, although it goes up higher. Those are some terrible losses... a challenge to stay zen in the face of them. How do you think the vine weevil grubs got into your pots? I had planned to replant the 1 year seedlings that look as though they might be viable. The young tissue is pretty amazing in it's ability to overcome injury, I've seen some that I would have sworn were ringed come back. I guess I missed seeing where there was a "bridge" in the cambium, but even still. I suppose I'll try it with the graft too, though I'm not optimistic. Will you apply any rooting hormone? -E
No hormones, just a straight replant in fresh soil. I replanted them on 27th of March and all are still alive so far, three weeks later. The one I showed above is pictured below (on the right) along with one of the others. Early days yet, but there is still hope. In the past I have had seedlings killed by these weevil devils, but only one or two at a time. This year has seen a population explosion for some reason. The problem is worse when the pots are standing on an area of hard surface, (like these were), because the only areas soft enough for the adults to bury their eggs are the soil surfaces of the containers. I now have some nematodes to control the vine weevil grubs, in the fridge ready to go, and I plan on buying some more in autumn and will use at least once per year in the future. Lesson learned. I may also bare-root repot the most precious seedlings every September/October to eliminate the potential for overwintering grubs. Funnily enough, I did not find any of the grubs when repotting those seedlings, so they either exhausted the food supply in each seedling pot and starved to death; or were killed by a -10°C frost in February; or they have already pupated to adult weevils. I am not sure if they would be capable of leaving one pot and crawling into another in search of more food. I did find two or three grubs when I repotted my 'Shaina' a couple of weeks ago, and that is in a different part of the garden.
I tend to agree with you Emery, in April you count casualties and this year has also been pretty bad. I also had a huge vole infestation last year, they ate 90% of my hostas and other assorted goodies. I had to do something and since over here it is impossible to buy snakes (best predators, cats do not make a difference killing one every once in a while), I resorted to chemical warfare. Here is a video that I made explaining the approach to other affected gardeners. It is very effective to lower and control overall count. Vole control Maf, I also had problems with weevil grubs, specially for maples in pots. For the last 3 years I have been using nematodes twice a year (Fall and early spring) and the problem has gone away. Gomero
