Saturday, 16 June 2012

A non typical black pine season ?

Black pines seem to do really well here in Cornwall as long as steps are taken to combat the rain. The trees sail through the winters with no frost protection and in a normal year they thrive and bud well in the Cornish sun. Soil mix is important though as rainfall is high and can last for days at a time - I've found through trial and error that just free draining isn't enough though as many particles in free draining mixes actually hold too much water.
            I've found the key 'water holding' ingredient is Akadama so we don't use much in the mix - just 10% of the largest particles I can sieve off. 40%  is large particle Kiryu, 40% expanded grey insulation 'balls' and 10% bark. This mix holds a small amount of moisture but has loads of air and loads of space - and with the inclusion of pine bark particles we seem to get superb growth of beneficial fungi throughout the pot.

In a normal year the first candles are cut off in June so another flush of buds form and open before winter with smaller, finer needles along with the bonus of extra back buds appearing at random,  but several things can hold back the first candle development enough to shorten the growing season and effect how the tree will develop over the rest of the year. A proper root prune and repot will put the tree back about 4 weeks and extended cold or wet weather in spring can hold back development even longer.

That just about perfectly describes 2012 so far ! as last Autumn (Sept 2011)  I sold my largest black pine locally and bought another much older tree in time for our club winter workshop. Starting work at the end of January I plucked off  95% of the needles, leaving just 4 or 5 pairs on the tips of each shoot, then wired the entire tree and restyled it at the workshop.   All the shoots had one single bud at the end and quite long mostly bare branches so the backbudding and ramifying was starting from scratch.

            Offering Picture,  tree arrived in Cornwall, and starting the first branch at the workshop

Needles reduced to a few pairs in the apex

A sign of several years without any proper candle pruning - no inner shoots at all and just needles on the ends - There is no point criss crossing the shoots to make a 'fake' pad though - spread out this way sunlight will trigger buds on the top of the branches. Its just a pity a few inner shoots didnt exist but the last BP I had started like this and ended up fully ramified.  Beggars cant be choosers though as there aren't many chunky aged black pines to buy in the UK

Because I'd bought this pine in from out of county it was important to get the tree repotted and into my soil mix as soon as possible as the heavier soil it was in was staying quite wet, growing a bit of liverwort and the trunk had been very mossy but sprayed with vinegar so it was dying off. In mid March there was the strangest few weeks of hot weather - our garden was in the mid 20's every day with reflected heat of the benches topping 28 degrees so the tree started extending the buds signalling repotting time. I have a plan with a few of my older conifers to repot every 10-12 years as I think repotting is becoming too frequent these days and the growth refines far better the more settled the tree becomes. The job of getting off lots of the old soil was even more important with this in mind as I dont plan on disturbing the tree again for a long time so I cleaned right up under the trunk base and between the main roots, using a blunt wooden stick to pick out the old soil. While working, a great flare of buried roots were exposed from below the existing soil level so I planned to move the tree up higher in the pot so they are seen - this gives an added bonus of an extra 5cm of new soil in the base of the pot too.

After the workshop and sat back on the bench in full sun, some of the surface roots have been exposed but this is before repotting.

Raised in the pot, old soil removed and root flare exposed.
I didnt expect visible growth to pick up for a month as probably half the roots were pruned back but then we got the wettest April , coldest May and now the wild windiest wet June I can remember !  The tree coped perfectly all right with the wet as the soil mix lets it all through but it has taken 10 weeks for the needles to start extending from the sheaths, and even now they are no-where near formed enough to candle prune and I think the tree will be weakened a lot by trying to make and open new buds in this weather.

One of the least developed set of candles - these will probably be left alone as they have so few needles already

Normally a method with a heavily repotted or weakened tree is to do nothing this year and resume candle  techniques next year, but I dont like the idea of doing nothing in the tree's development for a year so am going to try something different to let the tree keep some new needles, have time to make terminal buds that wont open this year, and with luck make back buds on older wood. Most importantly the tree has a fairly even distribution of vigour - many of the candles are much the same size - and I don't want to loose this balance by letting the tree grow free for a year.

Here is the tree today - June 16th - I'm going to go with the semi cascade as it is for a while and let a sacrifice candle grow wild on the tip to pull lots of strength downwards - in time the lowest pad may be removed if it balances the tree up better

This is all guesswork at the moment but this is the plan:
(Tree is already needle plucked to 3-5 pairs per shoot with one extending candle per shoot tip)

I'm going to carefully cut the new extending candles back to just leave 4-5 pairs of needless at the base as soon as there is space between the needles to get a fine pair of scissors in.

There needs to be one neat level cut leaving undamaged needles behind and I am hoping several new buds form on these cuts, but remain as dormant buds as the tree still holds some of this years needles.

Then I will just observe the tree for back budding, feed it really well and wait until Oct/Nov. If there are more than 2 new buds on any shoots they will be reduced back to 2, and the remaining older needles removed.

I'm hoping to have a tree looking similar - just 4-5 pairs of new needles on each shoot but this time with 2 buds in place for next year and some strong back buds (If we get a hot late summer some of these may have opened with a few needles if luck is on our side).

There will be an update or two on this black Pine experiment as the year goes on.

July 20th - a few strong candles have been cut off and new buds have formed on the cuts. We had a wet 3 weeks so I put the tree in the grreenhouse to keep it dry and visible growth increased. Tiny new buds are forming on top of some branches too. The bottom branch was simplified and one shoot will be kept as a sacrifice shoot to thicken the main branch.