Pieris

Hi likeitorlumpit. Pieris is just a username. My feelings about the plant vary from indifference to mild admiration. I've used Pieris on other forums, but I can't recall exactly why I chose it. I think I was a bit mad, though I've been much better since they changed my medication.

Thanks for the continued advice. I’m now looking out of my living room window at the tree; and, in the words of Lionel Bart’s version of Fagin, “I’m reviewing the situation”. Hamadryad, birches are among my favourite trees too. I agree there are many trees that are clearly either pubescens or pendula; but there are also many intermediate individuals that make life difficult for the amateur botanist. I once read a paper about wild populations of birch in East Anglia. The researchers examined the chromosomal make-up of trees and compared it with their morphology. Specimens with 28 chromosomes (diploid pendula) had strong silver birch characteristics. However, trees with 56 chromosomes (usually classified as the tetraploid pubescens) displayed any range of characteristics, from individuals that looked “pure pubescens” to others that looked “pure pendula”. There was a continuum of variation. On the sites they investigated, the team were unable to find any obvious hybrids – trees with 42 chromosomes – but they concluded the pendula-like pubescens trees were possibly/probably the result of introgression. ….Perhaps this subject needs a thread all by itself. Pieris

Hi there. I’m new to the forum and just read this interesting thread. I agree with everything Tony’s said and his knowledge is greater than mine. However, for many years I’ve had an amateur interest in soils, and I’ve carried out hundreds of pH tests, so I may be able to add a new perspective. Sorry if you already know a lot of this…I’ll go ahead anyway. To get a general idea of soils in a particular region I found it helpful to seek out some British Geological Survey maps – your local library may be able to obtain them. But be warned, while underlying geology often influences soils, the relationship between them may not be direct. Cranfield University provided soil maps of particular regions, with an analysis of soil profile types and likely drainage problems. But again, be warned – they charge. Over the years I’ve used various methods of testing soil pH, including garden centre meters, laboratory-standard meters and chemical colour tests. One of the cheapest methods is to wait for hydrangeas bloom in people’s gardens – if they’re all clear blue, the soil pH is likely to be 5.5 or below; if they’re all pink, the soil is likely to be neutral or alkaline. Another caveat – some gardeners cheat and use aluminium sulphate to artificially “blue” flowers. Cheap garden centre pH meters, while not totally useless, can give wildly varying readings. Lab meters are super accurate only if you take care of them with the proper cleaning/calibration fluids – and for most purposes you don’t need super accuracy. I think that with time you can learn to use the chemical colour tests and get to within half a point accuracy. If you can find them, get tests that provide ready-prepared indicator solution. If you get the tests with powdered test chemicals, remember to add only deionised water (same as for car batteries) or rainwater. Rainwater can add some acidity of its own, but at least that mimics the soil conditions that plants are used to. Don’t use tap water – it’s often very alkaline and will give inaccurate readings. Try to remove organic matter or stones from soil samples, since they can also throw readings off. Judge colours in daylight. It’s worth bearing in mind that soil samples from the same field, taken on the same day, can vary by almost a whole point, especially if the soil is near-neutral (5.5 – 6.6). Always pay heed to the activities of humankind – people apply agricultural lime; they carelessly discard bits of alkaline builders’ rubble. Have a look at pH readings from two similar soil types, one semi-natural, the other managed by man. Semi-natural soils are frequently much more acid. Soil acidity can be increased using ferrous sulphate or sulphur chips; the efficacy of adding acid organic matter is disputed. Many gardeners reckon it’s best to work with the soil you’ve got rather than try to make big changes. If you want to grow acid-loving (tolerating) plants, and your soil is close to neutral, I reckon it is worth creating slightly raised beds, beefing them up with acid organic matter and adding some ferrous sulphate. Hope this helps Pieris

Thanks for the advice; it’s great. Arctostaphylos uva-ursi (intriguing username), you’re right to think the tree has had no formative pruning. I removed a small witch’s broom when it was planted, but that’s it. Most of my interest has focused on wild trees, and in the garden I like to let things take their natural form. Clearly, not always a good idea. Anyway, I have some other birches that have behaved themselves and, with no help from me, produced good trunks with clear leaders. The tree in the picture is quite vigorous, possibly because it’s planted in a slight dip where moisture and nutrients tend to accumulate. I’ve had doubts about its exact nature, since it has shown some characteristics of Betula pubescens; but that's another issue, and one that seems to confuse even the experts. It’s put on a lot of growth since the photo was taken in December. It’s about six or seven feet tall now. I’ll take Hamadryad’s advice and just reduce the co-dominant stem on the left. What I’m concerned about is the possibility of included bark developing on the competing leaders on the right. Do you think it’s ok to remove them completely? Thanks again Pieris.

Hi, this is my first time posting on the forum and I’d be very grateful for some advice. I’m not an arboriculturist, just a tree enthusiast. I planted the birch tree pictured below about two and a half years ago. It was sold as a pendula whip, but the habit is not quite like most other silver birches I’ve seen in that it has lost a clear leader and has instead developed several co-dominant stems. Now I’m considering pruning it, but I’ve heard that birches don’t respond too well to pruning. My plan is to remove the co-dominant stem on the left completely. I’d retain the more-or-less central stem, which is in any case fractionally longer than the others, and remove its two competing leaders on the right. Would this be too much? Would I be doing the right thing? I may also shorten some of the lower lateral branches. I’d like to do the pruning now (I’m too impatient) but the advice I’ve read suggests I should wait because of the risk of excessive sap loss, though opinions differ as to the optimum time to prune birches. Some say late spring or mid-summer; others early autumn; a few suggest mid-winter. Anyway, thanks in advance for any advice on the matter. Pieris