4

Is it a bad idea to prune conifers when the ground is frozen solid?

I'm thinking about going up about 7' on a 30' tall tree.

black thumb
  • 8,786
  • 2
  • 30
  • 67

1 Answers1

4

Black thumb the middle of winter is just fine to prune anything. I prune a little on any and all plants any old time when I've got the pruners sharpened sterilized and in my hands. I love to prune.

If you are thinking of limbing up the trunk of your conifer, 7'? you should have a good reason why. It is sort of a no no for aesthetics as well as health of a conifer. If you do this you should also thin the rest of the tree to allow wind to flow through the tree. When people limb up a conifer without thinning they are the first ones to find a broken tree after a big wind. All conifer trees should be thinned; never topped nor limbed up. Unless you have a good reason and I've known those reasons and worked around them. Just go up inside your tree and thin branches choosing the weakest, most non productive branches to cut from the main trunk. Allowing air to flow through without catching a 'sail' so to speak. And prune no more than 1/3 of that tree, even during the winter.

stormy
  • 40,098
  • 3
  • 31
  • 75
  • our tree is starting to overgrow the driveway, and it would be a great bramble space for permaculture design. – black thumb Aug 31 '18 at 02:06
  • 1
    IF the ground is frozen solid, the wood above ground will also be frozen solid. IMO pruning any plant in that state is not a good idea, if only because it's easier to damage the plant rather than making clean cuts. There is nothing wrong with pruning *in winter* of course - though whether it's advisable to "prune" an evergreen conifer *at all* (as opposed to taking out complete branches) is another question. (and the answer is usually "no, unless you want a tree with a lot of dead brown foliage on it") – alephzero Aug 31 '18 at 18:44
  • @alephzero can you post this as an answer, even if the other answer's been accepted - for the benefit of future readers, you make a highly relevant point. – Bamboo Aug 31 '18 at 20:34
  • The vascular system of trees is like leaving a dripping faucet, keeps the cambium from freezing. Thinning conifers is important for air flow. I am not sure what you mean as opposed to taking out entire branches? That would be thinning. Removing branches that aren't doing the tree any good and the tree will slowly but surely abscise those branches anyway. I am fairly sure that trees are not frozen solid in the winter. Bark has air filled cork layers that are great insulation. Different trees have different mechanisms. Some use other chemicals to raise the freezing point. – stormy Aug 31 '18 at 20:47
  • Heading and shearing conifers is rarely done, arborvitae for example needs careful shearing. I also wrap certain conifers in the winter with burlap and twine, some with old fashioned incandescent christmas lights beneath the burlap. That would be for trees a bit outside their proper zone...and once a humongous Jelly Palm. It is still alive today in the Northwest! In relation to the parts of a plant; the weakest or most fragile part are the roots, next are the leaves (thus deciduous) but the trunk and branches do not freeze unless out of these zone or a very bad winter. Maunder Minimum? – stormy Aug 31 '18 at 20:54
  • @Bamboo and Alephzero if you have information on cambium of trees having the ability to freeze solid, I'd love to see this stuff. Freezing of live cells even in dormancy kills cells. Think about the thawing of fruit tree bark on the side that gets the sun. We paint them white to reflect the IR, so there has to be something going on with freezing. Internet seems to be lacking in this search item. – stormy Aug 31 '18 at 20:59
  • Called Sun Scald...the excessive IR on the southside of a tree during the winter will OPEN up perhaps WAKE up live cells that are in dormancy and protected. Then those cells are vulnerable to the cold and will rupture as they freeze without their blankies pulled up tight. Similar to plants going into dormancy and then hit with an Indian Summer? they decide to grow new growth and that growth then freezes and dies. Pruning in the winter is just fine. I have never ever found frozen branches that turn to mush when pruned. If I am wrong I want to know, grins! – stormy Aug 31 '18 at 21:07
  • @blackthumb What permaculture thingy are you thinking to do. Sorry, I just think there should be a different label for knowledgeable gardening. Ain't ever gonna be permanent, right? What tree is it that you are talking about? This conifer, that could be enlightening! Grins! – stormy Aug 31 '18 at 23:02
  • @stormy you're not wrong - xylem and phloem in cold hardy coniferous plants do not freeze, BUT, we don't know what variety of conifer this is, and pruning back in the dead of winter is not advisable - freezing and thawing can damage parts of a conifer anyway, so pruning in such cold temperatures will make the tree much more vulnerable to freeze/thaw damage - I was hoping alephzero would expand on his answer – Bamboo Sep 01 '18 at 09:04
  • What is freezing and thawing? Let's slip over to chat tomorrow or whenever is convenient. I brought up the stuff about the sunny side of the bark of fruit trees, that causes thawing and then the freeze will kill that tissue. I am a bit stumped...so I'll catch you in chat soon! – stormy Sep 01 '18 at 09:15
  • And when frozen, plant cells die. Conifers planted in the wrong zone need to be wrapped, wired with incandescents for the winter. Pruning won't be their worst problem. – stormy Sep 01 '18 at 22:49
  • @stormy freeze and thaw in terms of weather events, as in sudden temperature fluctuations,can damage even cold hardy conifers is what I meant, so if the tree's been pruned in dead of winter, more may be lost due to weather conditions before winter's over, see lower down in this link http://nwconifers.blogspot.com/2017/01/how-do-conifers-survive-cold.html – Bamboo Sep 02 '18 at 10:11