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davidrt28

should leylands even be considered zn 6 hardy?

OK, OK, I know some of you will roll your eyes and think "no, not another leyland thread." So, yes, let's not revisit their relative merits even where hardy. My concern is this: they've always been rated zn 6 hardy. Yesterday, I was up in Lancaster and Berks Counties in south central PA. This area is zn 6 rated. I saw many, many damaged leylands. Some severely so...a couple appeared completely killed. Problem was especially evident on trees out in open fields and high, windy spots: a few sheltered ones in towns were less damaged. These were well off the road, so it wasn't salt spray. (and besides, some right by the road were damaged, while other coniferous evergreens like Norway spruce and 'Green Giant' had not a bit of visible damage. Salt spray would have damaged them all. Only saw a couple but Japanese Cedars were also not showing any cold damage.) I wasn't able to get a picture of any both because I didn't have my camera with me.

Granted this was a severe winter, but temperatures in that area did not exceed zn 6 thresholds. In other words, it did not go below -10F...and yes, of course that can happen in zn 6, that's why its an average. It did go below 0F more than once, though. As bboy and others point out...the zone designation of truly permanent plant material (as opposed to things like bulbs and subshrubs) should account for almost any cold weather circumstance in a area: precisely because you don't want to deal with a 100 ft. long row of 20-30 ft. tall sickly looking plants. So IMHO if a once in 20 year winter produces that kind of damage in zn 6, they just aren't zn 6 hardy. Or maybe "Tree hardy" if you will...in other words, you could deal with a 6' shrub having some dieback, not a tree.

Other bit of news is perhaps because they are coning, I spotted several douglas firs. All of them just fine looking, and one right in the middle of Parkesburg, particularly nice looking. However I have never seen these in a non-botanical garden setting anywhere south of the Mason-Dixon, at least in the Piedmont...other than years ago on a steeply sloped bit of construction fill at the 500' elevation Tysons Corner. (highest point in Ffx Co., VA) Proof again of what a climate divide the Mason-Dixon is. Thus perhaps it's not surprising that most of the leylands here along the bay are fine, I've seen a few slightly singed ones. Mine were totally undamaged at 3F, including the related cross C. x ovensii which is generally considered less hardy, but has had much more disease resistant foliage. (mine were planted by the prior owners to help sell the house...I would have chosen something else and in fact removed many of them years ago. I planted the C. ovensii of course!)

Comments (16)

  • hairmetal4ever
    9 years ago

    It's no great loss if not. Sorry, just had to say it.

    I think (and a lot of Upper Midwest and Great Lakes people can verify) that the deep freezing of soil with ill timed sunshine caused more damage than simple low temps. So the damage was more like a z5 even if they were zone 6 temps.

    Interesting about Dougfirs up there. We may move to York County next year. I wonder if that would be enough difference for them to do OK.

    I think just the 3-4 degree difference in average summer temps (nights are probably cooler especially) makes the difference.

    I wonder if Abies concolor would do OK up there.

  • ken_adrian Adrian MI cold Z5
    9 years ago

    dont fail to take into account.. cold blistering winter winds ... they can desiccate.. freeze dry.. plants that dont like such ...

    and it has not much to do.. with min low winter temps ... a 20 mph january wind.. at zero ... is crippling to borderline evergreen plants ... and that is not zone info.. which is usually just predicted low temp ...

    throw in a sunny winter day.. tissue thaws.. and at dusk.. the wind picks up.. and over a period of a few days.. freeze.. thaw .. freeze .. thaw ... etc ...

    i like to say.. get them dormant.. keep them dormant.. its the going in and out of dormancy in winter.. that kills things ...

    and it is part of the sunscald theory on tree trunks.. the side facing the sun thaws... freezes.. etc ... and then the bark fails ....

    limiting suggestions to why winter damage occurs.. to min temp only.. really leaves out a multitude of other potential issues ...

    all that said.. buy one.. plant it.. dont invest in making it a sight block that will fail [most peeps who come here asking about it ... want a fast growing site block] .. dont plant it 3 inches from the house ... no one can really tell you.. what will grow in your micro climate ...

    who knows.. maybe it will thrive for decades ... maybe not ... find out

    ken

  • davidrt28 (zone 7)
    Original Author
    9 years ago

    Oh, I definitely agree it's not a great loss from our point of view. But I'm sure the people who paid some landscaper to install a 100-200 ft. long barrier hedge are not happy.

    I guess my point with the thread is again to distinguish between the "really 100% rock hardy winter will never hurt it" zone rating, with the "standard commercial" zone rating. A nursery only cares that you don't see damage in the next couple years, so they won't have a warranty claim and you'll keep being a customer. For a permanent planting feature, you really need to use the "100% rock hardy winter will never hurt it" rating. IMHO that's only zn 7 for Leylandii.

    I'm sure douglas firs will be fine in 99% of York County...just maybe not the swamps or islands in the Susquehanna haha.

  • davidrt28 (zone 7)
    Original Author
    9 years ago

    hairmetal - I can't remember exactly, you are in Frederick County, right? Have you seen damaged leylandiis out there? Even if you look at the 270/70 corridor, there's a fairly pronounced difference between lower Montgomery Co. and anywhere N & W of Frederick. I can easily imagine exposed areas up there could be just as cold as parts of Lancaster Co. The climate data for Camp David is somewhere out there on the net, and even that small amount of elevation makes the nights much cooler.

  • sc77 (6b MA)
    9 years ago

    I'm Zone 6b MA and have been growing 5 Leylands as a hedge for the last 4 years. No damage until this year, but the damage was not significant, it was basically just trimming off a bit of dieback on the ends of the branches, maybe 6 inches of dieback at most.

    This was probably the 1st or 2nd coldest winter in the last 30 years, so I think Leylands *can* be considered hardy to z6, although every zone is different. I think Ken's point about winds are important, my hedge is not in the open, so that don't take a direct shot of winter winds. I'm pretty sure they would have been toast out in an open field this winter.

    I couldn't resist the temptation to get the fast growing Leylands, despite the hate for them on the forums. I suspect I will join that group in 10 years or so when they get diseased and die, but it the meantime, I find them to be really nice, faster growing (for me) then my green giants. If/when I do replace them, it will be with Green Giants, just a better choice for the area overall.

  • davidrt28 (zone 7)
    Original Author
    9 years ago

    Thanks SC. Good to get another view of the matter. Are leylands very popular in coastal Mass (I assume that's what 6b means) See any other damaged ones? The sandy, rocky soil there could be less "rich" than the somewhat legendary soils of Lancaster County...causing the plants to grow in a somewhat more restrained and sane manner. Therefore having better root systems that could survive cold winter conditions better. I now remember a McMansion over in Harford County, the next county over closer to Baltimore, I would sometimes drive past. The guy had planted a bunch of leylandiis and was clearly fertilizing them like crazy, trying to get fast growth. Those are some of the only ones around here I remember looking burned. So I think this cultural factor is coming into play. (over fertilization)

  • StGuaposFire
    9 years ago

    There's quite a few dead Leylands here in New Castle County as well, and we're zone 7, so you could say they aren't even really zone 7 hardy in some extreme cases.

    S

  • coachjohnsonlp
    9 years ago

    I am in zone 6B in NY currently and there are dead Leylands all over the place. Every property that I ave seen with Leylands has at least one if not all of them totally brown. Some pretty big ones as well.

  • sc77 (6b MA)
    9 years ago

    I am actually south west of the Arnold Arboretum, so closer to the 6a border, than I am to the coast. A lot of times people don't realize that Cape Cod and the Islands are actually zone 7a. They sell Leylands at all of the big box stores around here, but now that I think about it, I can't recall seeing too many in peoples yards (either healthy or dead). The vast majority of hedges around here are emerald green arborvitae, which get trashed every year due to their inability to handle snow load without splaying. I inherited a row of 12 on my property and have to tie them up every year.

    Our soil is defiantly rocky, sandy, fast draining. I don't get anywhere near the growth rates reported for these trees. I bought the leyland's at 2ft tall and now they are about 6ft tall 4 years later, so they are only growing about 1ft per year, although they have picked up speed this year.

    This post was edited by SC77 on Sat, Aug 9, 14 at 23:23

  • hairmetal4ever
    9 years ago

    David - I'm in Howard County, actually, and there are spotty dead Leylands around. Usually in a line of leyland trees, you'll see one dead one, always right in the middle! Probably less than 25% have any damage at all but of that 25% some are pretty bad.

    It was a weird winter for sure. I think the March cold snap did the most damage, actually. I think some were just waking up, just a little, due to the stronger sun/longer days, then BAM - almost zero degrees. Deciduous plants did not seem to be affected, as they were still leafless, but I think some evergreens (BLEs too - some Ilex seemed to have some burn too but have "grown out" of it by now) were hit by this.

  • hairmetal4ever
    9 years ago

    SC77 it seems at least the very sandy soils near coastal MA make it so that despite fairly good rainfall, it's like growing in a much drier climate.

  • edlincoln
    9 years ago

    I live in Zone 6 MA and there are a few Leylands growing in the area...they generally seem to survive the winter OK.

    It occurs to me the best use for Leylands might be to provide a temporary sight/wind block while other trees grow. Plant a row of Leylands, plant a row of something slower growing and longer lived in front, take down the Leylands when they die.

  • bengz6westmd
    9 years ago

    Same here David -- many Leylands damaged by last winter, tho larger mature ones look OK. Leylands simply shouldn't be planted anymore.

  • davidrt28 (zone 7)
    Original Author
    9 years ago

    Interesting reports, thanks! So, "not as hardy as is widely promoted" seems like just another problem with this plant. In addition to the disease susceptibility and weakness in storms.

  • pineresin
    9 years ago

    "In addition to the ... weakness in storms"

    Leyland Cypress is actually very storm-resistant, PROVIDED it is planted carefully and allowed to grow naturally.

    The problem is first, that all too often it isn't planted carefully, with coiled roots from the bottom of the pot left coiled. This is asking for trouble with any tree, but is commoner with Leylands as they grow so fast at the nursery they fail to keep pot sizes large enough for them. Second, that people cut the tops off, resulting in forked trunks which are liable to split later.

    Spread the roots out carefully at planting, and never top the tree, and it'll cope very well with gales.

    Resin

  • davidrt28 (zone 7)
    Original Author
    9 years ago

    Well Resin with all due respect, other than your rare 1987 superstorms, storms are generally more severe here. Between the hurricanes, heavy snowstorms, and thunderstorm squall lines. I can't tell you how many times I've driven around the suburbs of DC, Baltimore or the Delaware Valley and seen a row of leylandiis with one plant upturned or one with a snapped trunk, whether that trunk was already bifurcated or not. Just in my yard in the past few years, I've had several hardwoods downed completely, several large hardwood branches, an entire Juniperus virginiana top blown off, etc. I have a little over a hectare (see I'm using metric for you!) but over 1/2 of the perimeter is unmaintained, primary-succession "trash" forests. That means short to medium lived trees like maples and ashes. (As is so often the case in the northeast of the country, this was abandoned farm land, I've seen old aerial photos showing nothing but farm field where now there are woods. Millions of acres of New England reverted to forest and this was the case even as far south as the Elk Neck Peninsula right near me) In fact now after 60 or so years of primary, the secondary species are coming in, like beeches and tulip poplars.

    This post was edited by davidrt28 on Mon, Aug 11, 14 at 21:49