A Little Bit More
The term “evergreen” is most commonly used to describe the many different species of conifers that grow across North America and may give the impression that ALL conifers retain their needles – now you know better. The term “evergreen” really is more of a horticultural term rather than a scientific one although it is used by both scientists and laymen alike. One way to clarify the term is to refer to plants as either broadleafed evergreens (referring to the broad or wide leafed deciduous plants) or narrowleafed evergreens (referring to the conifers with their narrow needles).
Broadleafed evergreens also include the hollies, euonymus, pyracantha, gardenia, boxwood and camellia – deciduous plants that are familiar to many of us. The loss of old leaves and the growth of new ones happens in such a way that the plant is never without some green leaves and is therefore an ever green plant.
Narrowleafed evergreens such as the pines and spruces lose their leaves (needles) too but do so after several years – there is always one or more year’s worth of living needles to make the tree ever green.
Activities
Bring It In
Objectives: See what kind of evergreens are growing in your particular area
Materials: Whatever you can find
This activity will vary, depending on the area in which you live and will be most appropriate in northern (temperate) areas. In the temperate areas of the world (areas where there is distinct difference between summer and winter) evergreens are easier to recognize due to leaf drop of most other deciduous trees and shrubs.
See if your students can find an evergreen plant near school or home. They really won’t need permission to remove just one or two leaves from a chosen plant but they do need to be sensitive to homeowners/landowners.
If they can bring in a green leaf or two from a living broadleafed plant (not a dead leaf that’s still on the tree), I think you’ll find that the leaves are rather thick and sturdy – not the delicate kind of leaves you’d find on a maple or elm, for example. Should be interesting to look at several kinds of these and realize they’re all pretty “sturdy” leaves.
Questions:
- Why do you think the broadleafed evergreen leaves you brought in were on the “sturdy” side? The delicate leaves we see in the summer are more susceptible to damage with freezing temperatures. The leaves of the evergreens are more sturdy and can withstand freezing and thawing without damage.
- Did you see any trees that still had their leaves but weren’t green? Some trees don’t lose their leaves in the fall even though they’re dead (the leaves that is). Many of the oaks and the American Beech retain their old leaves through most of the winter months and don’t drop them until spring.
Can you think of any value to a tree to keep living leaves for more than one year? Trees that hold on to their leaves over more than one year can get a quicker start on photosynthesis in the spring – they don’t have to wait for new leaves to grow since they already have some living leaves.
Key Concepts
Identification, Structures and Functions
Questions
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Posted by M Kris Neal on May 04, 2006 at 03:58 PM
Q: I have an evergreen in my front yard. I know that it has been there for 20 years but I don't know how much longer than that. One side of it started dying and my husband cut back the whole side of the tree. (This caused an arguement) He insists that it will grow back. It has been a year and of course it hasn't. This is not a yew. It is only about 4 or maybe 4 1/2 feet tall. I think it is some kind of fir but I am not positive. It has small (1/2 inch) needs. I think it needs to be removed because it is beyond repair. I can't find a site that will help me with this issue and was hoping that you might. Thank you.
A: Your photos were excellent - thanks so much! Your tree is an Alberta Spruce. This particular species is very popular with homeowners and makes a nice foundation planting. Most of the conifers (pines, spruces, and firs) won't bud back if you remove all of the live material on a given branch. You can see that on your tree there is lots of new growth at the top but NONE in the cut areas - and there never will be.
If you really like that particular tree species, why not go down to your local nursery and have them provide a replacement. You are correct that yews will bud back even after hard pruning but since spruces won't, if they start dying in one area, you've pretty much lost that part of the tree.
Although your tree really looks vigorous at the top, I'm not sure why it would have died on the side. Did you do some spraying there last year that may have gotten on the needles? Looks to me as though there is plenty of light on that side so the tree should have been fine. Keep in mind that spruce don't do well when shaded. Best of luck to you. How's come wives are right so often?:-)
Posted by heide wilkes on May 01, 2006 at 10:25 AM
Q: I have a pine tree approx 10 yrs old; unsure which variety.
The middle area close to the trunk has branches that are very droopy and limp. Does this indicate lack of water? Thank You from Michigan
A: Pines require lots and lots of sun for growth and do poorly when shaded. It sounds as though some of the inner branches are being shaded and this is causing their weakening and will eventually cause their death - not the tree, just the branches. Take a look at your tree and you'll probably notice that the upper and outermost branches/needles that receive full sun are the most healthy. Pines are especially adapted for life in dry soil so I'm quite sure your tree isn't suffering from lack of water. Hope this helps.
Posted by Karen Kelly on April 30, 2006 at 09:14 AM
Q: I planted a weeping larch early summer last year in northern New Jersey. In August the company treating my shrubs sprayed the larch which was very healthy on a day when the temperature was in the nineties. The larch subsequently lost all of its foilage within two weeks. So far this spring there has been no indication of new growth. Has the larch been lost?
A: This doesn't sound good! Larch do lose their needles in the fall, as you probably already know, but losing them in August sounds deadly to me. A good way to know about this year is for you to check out the buds. My larch (native American Larch) here in upstate NY are already putting out tiny needles so your larch should be out by now I should think. But, to be on the safe side, look closely at the buds and see if you can tell if there is any green. If the buds don't look like they're greenish and beginning to swell and/or the branches are brittle, part or all of your tree is dead. What a bummer. I think the larch are some of our most beautiful trees so hope you can replant this year if necessary and avoid spraying as well. Thanks for asking.
Posted by Keri Bartow on April 24, 2006 at 04:18 PM
Q: How does a tree grow new leaves if the old ones have not fallen off? I live in Eugene, Oregon, and the climate here is moderate-and not all the trees lose their leave in winter....so how do new ones form?
A: Although evergreen trees (pines, spruce, fir, rododendrons, hollys etc) do retain some of their leaves from one year to the next, they also have buds each fall for the next year's growth. These trees produce new leaves and new growth each year but the older leaves, these may be one or two or sometimes even older, stay on the plant for a longer time. If you look at your local pines, you should be able to see the buds on the branch tips that will sprout new growth this spring. Granted, the buds may be really small right now, but soon will begin to swell and then burst into the new growth. Hope this answers your quesiton. Thanks for asking.
Posted by aiesha james on April 18, 2006 at 04:50 PM
Q: what is the differene between an evergreen tree and a deciduous tree?
A: The term "evergreen" is a bit misleading since it is more of a horticultural term (used by people that grow plants) rather than a scientific one. Basically, an evergreen is a plant that retains its leaves through the winter and is never without some green leaves even though the older ones are lost periodically. We usually think of the conifers (pines, spruces, firs) as evergreens but so are azaleas magnolias, and rhododendrons. Deciduous trees are those that lose all of their leaves at the end of the growing season. We usually think of oaks, maples, and elms as deciduous but trees like the larch (a conifer) does lose its leaves each fall too. You're right - it is confusing. Hope I've helped a bit.
Posted by jules D on April 03, 2006 at 08:51 AM
Q: I have a beautiful Weeping Blue Atlas Cedar tree in my garden. The problem is, I don't know if I lost it. It lost all of its needles. It is now early April and I do not see any new buds appearing. Does that mean it's dead? The bark looks wonderful and other than the fact that it lost all of it's needles, it doesn't look dead.
A: Although some "evergreens" do lose their needles (larch is a good example) in the fall, the Atlas Cedar does not. I'm afraid you've lost your tree. You didn't mention where you live so I can't comment on whether your area is appropriate for this species or not. Some of the cultivars of trees (such as your weeping variety) are not as hardy as the orginal stock so your tree may have been in a border-line location or geographic area. Your local nursery should have info on whether this species and variety are appropriate for your area. I know it's quite upsetting to lose a tree that you enjoy so I hope you can replace it with something that will thrive in that location. Do keep in mind too that all kinds of things can affect a tree so disease may also have been a factor too. Hope I've helped a wee bit.
Posted by Felicia clemons on February 03, 2006 at 02:42 PM
Q: Besides experience, what is a helpful way to identify deciduous trees in winter??
A: Experience, as you've guessed, really does help but that's what "practice makes perfect" is all about. Deciduous trees in winter can seem quite perplexing at first but there are a variety of puzzle pieces that one can put together to figure out what you're looking at.
To begin with, it really helps to have a good book or two on tree ID for your area. This doesn't have to be a professional book but simply one that points out the typical trees one is likely to find in your general area of the country with some good illustrations. Knowing what trees are likely to be found where you live, really narrows the field. Granted, field guides tend to focus on tree leaves but they often provide tree profiles and illustrate their fruits and silouettes that helps too. It's also important to consider the habitat one is looking in - mature woods, young woods, bottomland near water, dry, sandy areas etc.will often be remarked upon in field guides and these can help you know where to "expect" to find certain species. Knowing what grows in a particular habitat certainly won't guarantee tree ID but it helps put things in perspective. Be sure to take a look at the bark, whether or not a tree is oppositely or alternately branched and when all else fails, look on the ground for last year's leaves - these often can be extremely helpful although you can't always be sure which tree they fell from. There are some good tree guides that use buds and bare twigs for ID but these are for more advanced searchs and may not be suitable. During the summer months, when tree ID is much easier, get a good look at the various trees in your area and identify what you can and when winter arrives and the leaves are off the trees, you'll probably know most if not all of the trees you see.
One word of caution; if you look at trees in town or yard, you're quite likely to run across an assortment of exotic trees from other areas so don't let this throw you off when making an ID with your field guide. I personally find trees to be extremely enjoyable and like the fact that they stand still and give you all the time in the world to look at them closely! Hope this helps and thanks for asking.