Bad power line pruning

Driving home today, I saw this lovely sight:

powerlinepruningOur local utility company has been busy butchering trees around the power lines.

Every plant person I know complains about this, but I honestly don’t think there is much hope for a change. Power companies don’t want limbs falling on the electric cables during storms, and they’re not likely to start spending money to hire real arborists to do the pruning.

What I really wish is that people would start thinking a little more before putting in a tall tree directly under electric lines. I’m sure these went in as cute little babies, I know it can be hard to visualize what a small tree will grow into, but we do really need to do a better job of it. If you are looking to plant, take the time to look up the tree in question and see how fast it is going to grow. Google will usually tell you, and if you are planing conifers, the American Conifer Society has an amazing website which will tell you the growth rates in inches per year of just about any conifer you can imagine. Check it out, and do the math, and see just how fast that little spruce is going to be causing problems before you start digging holes.

Fall is for Planting…Ornamental Grasses! But so is Spring…

I’ve written previously of my adoration for ornamental grasses.  A few of you folks in the mid-Atlantic might have heard my “Grasses for the Masses!”  presentation complete with lots of arm-waving. As with most of my talks, there’s usually some sort of interpretive dance involved.

Most of our warm-season ornamental grasses are in full gloriousness at the moment.  Because it’s autumn! ‘Tis the season to purchase, plant, and enjoy ornamental grasses!

Pennisetum 'Karley Rose' - available at a garden center near you!
Pennisetum ‘Karley Rose’ – available at a garden center near you!

Well, not really.  If you’d have purchased and planted them in April or May, you’d only have to do the “enjoy” part now.  And your local grower/garden center would LOVE you for it. But most gardeners overlook containers full of  6″ tall Fescue – which is what a LOT of our best grasses resemble in the spring.  It’s always been challenging to sell “green” in the spring – consumers want to see and buy plants in flower – so nurseries and greenhouses that supply garden centers do their darnedest to provide said blossoms.

Gorgeous grasses at Babikow Greenhouses near Baltimore, MD.
Gorgeous grasses at Babikow Greenhouses near Baltimore, MD.

So we pass over pots full of green grassy things in favor of enticing blooms. Nurseries have picked up on this – many include grasses in their summer/early fall production schedule, making full, fluffy pots for the autumn gardener.  This works o.k. for shorter, compact things like fountain grass, little bluestem, etc.   But by September, majestic switchgrass, big bluestem, and the like rarely look that fabulous in a one or two gallon pot – the proportions aren’t right; a bit of wind and rain and the situation is ripe for floppage (closely related to splayage). So you’ll probably pass them over. Again.  Or maybe…take a second look? Just cut them back and plant away – you’ll enjoy them NEXT fall.

Little ball of horrors

One of the great things about doing a multi-author science blog is that there will be topics about which colleagues will disagree. One of those topics revolves around the best way to prepare woody rooted plants (trees and shrubs) before planting them. This is an area in arboricultural science that is evolving. A search through our blog archives will find many of these posts and for convenience’s sake I’ve linked one from each of us here.

From Jeff (2009)
From Bert (2014)
From Linda (2013)

Rather than belabor the points that Jeff, Bert and I have already made in our posts, I think I can sum up our major difference here: I like to bare-root trees and shrubs completely before planting (so I can correctively prune all flawed roots) while Bert and Jeff prefer a less invasive approach. What we do agree upon, however, is the deplorable condition of the roots of many trees and shrubs that end up in the nursery. Because I do practice bare-rooting trees, I thought I’d use today’s post as a rogue’s gallery of trees that should never have made it to the retail nursery. (All of these trees were ones that I bare-rooted and root-pruned myself before planting – and all are thriving.)

Ginkgo "knee" root
Ginkgo “knee” root
Interlocking redbud roots
Interlocking redbud roots
Junky Japanese maple
Junky Japanese maple
The duct tape around the trunk is where the burlap bag began. While the roots are in pretty good shape, only root-washing could find the root crown of this tree.
The duct tape around the trunk is where the burlap bag began. While the roots are in pretty good shape, root-washing revealed the root crown of this tree (which the “at grade” part of the tree) 10″ below the top of the bag

Confessions of a Lazy Gardener

NeglectedBed1

I admit it.  I can’t keep up … I’m not as industrious as most of my gardening friends are when it comes to the effort necessary to manage my 6 acre landscape.

It can get overwhelming, especially when there are previous beds that came with the property that had been neglected for 10 years or more by the elderly lady who owned the property before us, and where perennial weeds are well established.

I make a valiant effort in the Spring, with all the enthusiasm of the new season to clean them up … dig the perennial weeds … plant something new (usually a division, or a naturally layered specimen, from elsewhere, or one shared from friends), but by mid-July or so, I have to redirect my efforts to the places that I’ve created … the shade garden … the rock (mostly sedum) garden … mulching the new trees and shrubs, and of course my tomatoes, so these previous places don’t get the attention they deserve.

But then again, some surprisingly beautiful, and beneficial results can happen in spite of (because of?) the neglect …

NeglectedBed2

This is a “pre-me” bed of mostly Japanese Anemone stretching between two arbors, with Trumpet Vine (Campsis radicans) (pre-existing), and Climbing Hydrangeas (Hydrangea anomala) (me added), anchoring each end.

The Goldenrod (Solidago) and White Snakeroot (Ageratina altissima I think) now dominate, along with Sweet Autumn Clematis (C. terniflora), a non-native introduction that appears on watch lists as an invasive species in our area.

Syrphid1

Yet look at the insect life.  Scads of hoverflies (some species of Syrphid), who in addition to their role as pollinators as adults, are voracious consumers of aphids in their larval stage.

Scoliid

Scoliid wasp, predatory on Japanese Beetles.

Ailanthus Moth

An Ailanthus Webworm Moth (Atteva aurea), which uses the invasive Tree of Heaven (Ailanthus altissima) as its larval source for food.

Honeybee

And my, and most folks favorite these days, honeybees (Apis mellifera)

Hydrangea

And if I kept up the weeding of this neglected bed, would there be a self-seeded Hydrangea paniculata available to transplant elsewhere?

So, probably a rationalization to justify my laziness … but looking on the bright side, there can be beneficial results from my neglect.

Why doesn’t my plant look like it did last year?

I get versions of this question often. You have something in the garden, but this year it looks a bit different than it did before. There are a bunch of different things that could have happened to cause this change, and I’ll attempt here to make a complete list of them.

Rootstock

Trees and shrubs, including things like tree peonies and roses, are often grafted, so the part with the pretty flowers or delicious fruit is stuck onto the roots of a different variety, often not as pretty/useful/tasty but more vigorous and/or easier to propagate. Sometimes shoots come up from that rootstock and take over the plant. The best sign will be to see if the shoots that look different are coming up from the very base of the plant. Cut all the shoots with the off-type flowers or fruits as completely as possible to allow the desirable parts of the plant to continue on.

Reversion

This is most common with variegated plants that are chimeras, though there are a few chimeral varieties which have multicolored flowers rather than multicolored leaves. I wrote about what a chimera is here, but the short story is: Many variegated plants are made up of two different cell types living together. If one cell type starts taking over, you loose the bi-colored effect of the variegation. As soon as you notice them, cut out the reverted shoots to keep them from out growing the multicolored parts.

A variegated sport on a lilac
A variegated sport on a lilac

Sports

Sports are chance mutations, and sometimes a flower will just up and change color. Usually, a sport will only change one aspect of a plant, most often color, while size and shape and everything else stays the same. New variegated varieties almost always come into being as sports. Sports will almost always be isolated to just once branch or section of the plant while the rest of the plant maintains the original color. If you like the sport, you might want to try taking cuttings. If it is an attractive sport of a popular plant, it might even be valuable.

Seedlings

Sometimes it isn’t that the original plant changed, but rather that it had some babies, and the babies look different. Confirmed self-sowers like phlox and aquilegia are notorious for this. You get a nice variety, but in a couple years, it has died out and replaced by a few seedlings which usually aren’t as nice. To prevent this, dead head after flowers fade to prevent seeds from developing.

Soil

Hydrangeas famously will change flower color depending on the pH of the soil in which they are grown. However, this is rather an anomaly, and soil conditions have no impact on the look of flowers for the vast majority of plants.

Climate

Some flowers will change their look, sometimes radically, depending on climatic conditions, often getting darker or lighter depending on temperature and the amount of sunshine. So if a plant looks different in a year when it has been unusually hot or cold or cloudy or sunny, it will probably go back to the normal coloration once your weather returns to normal.

Nursery conditions

Often plants you get at the nursery will look quite different once they’ve spent some time in your garden. Many plants from the nursery will have been treated with chemicals called plant growth regulators which are used to keep the plants short and compact. As those compounds wear off, the plants will grow taller and looser. Also, commercial greenhouses are usually warmer than your garden and often exclude UV light which can chance the coloration of a lot of flowers.

Contamination

If your neighbor gave you a clump of their favorite old bearded iris, but after a couple years the iris they gave you is replaced by a different color or a different plant altogether, they likely accidentally included a bit a different, more vigorous plant along with the one they gave you. Your best option here is to lift up the whole clump, wash all the soil off the roots so you can see exactly where one plant ends and the other starts, and just replant the ones that are true to type.

irisglyphosate
A whiff of glyphosate caused this iris flower to bleach out.

Herbicide drift

If you are spraying something like glyphosate (active ingredient in roundup) sometimes a bit of it can drift onto plants, not enough to kill them, but enough to cause them to be deformed or discolored. Glyphosate drift in particular will often cause flowers to be bleached out, white or nearly white. In this case, just be more careful next year, and everything should return to normal.

Forgetfulness

Okay, let’s just admit it. We don’t always remember that we moved something or what we bought or exactly what a new plant looked like last year. Sometimes there is no great scientific mystery beyond the fact that we’re all busy and don’t keep as good records as we know we should.

Joseph Tychonievich

Puya report!

For all five of you that might have paid attention to my posts on the genus Puya (which does in fact rhyme with booyah…thank you my west-coastie friends):

Here’s the update that you’ve been waiting for!

Puya is a horrifically spiny, painful, and hateful genus in the Bromeliad family. Native to the Andes, the fish-hook-like spines snare passing mammals; the rotting flesh provides nutrients to the exceptionally lean soil of the arid steppes on which it sort of grows/becomes grumpier.

Puya flowers once an eon, in a spectacular [but ill-earned] display that turned me to mush, based on a photo in an Annie’s Annuals catalog (see my “eternal gardening optimist” post). Autumn of 2012, I ordered and received one healthy Puya berteroniana in a 4” pot. Heckling commenced.  Overwinters in a 40 F greenhouse, where it was watered once or twice. Summers have been spent on our deck. Osmocote has hopefully provided required nutrients. Expected to kill her within months, as it is SO VERY not native to the verdant and humid Blue Ridge mountains of Southwest Virginia.

Happy and amazed to say Pootie [what was I going to name her? Bert??] is in her 3rd year – continuing to grow, and, AND, captured her very first mammal!

Pooyah!

Okay… so it’s a fluffy stuffed possum, and the dogs dropped it from the deck above. But snagged! You know Pootie got a thrill…

The Science Behind Fall Color

Japanese maple (Acer palmatum) in full fall color
Japanese maple (Acer palmatum) in full fall color

In many parts of the U.S., particularly the northern U.S., we are blessed each year by nature’s display of bright color dotted through the landscape. Fall color of leaves at the end of the growing season provides a remarkable encore in the landscape. There are many trees and shrubs with great autumn leaf color and I will address some of them in my next week’s post, but this week, I will talk about what actually happens inside the plant during autumn.

Plant Pigments

As the days get shorter and temperatures start to cool, particularly at night, the season changes from green leaves into a kaleidoscope of yellow, orange, red, purple and bronze shades. There are a variety of factors that interact and play a role in determining how colorful the display will be. Plant leaves contain several pigments that determine the color that will appear and variations arise when different concentrations of pigments are combined in the leaf.

Eyestopper™ Amur corktree (Phellodendron amurense 'Longenecker'), a male cultivar with bright yellow fall color
Eyestopper™ Amur corktree (Phellodendron amurense ‘Longenecker’), a male cultivar with bright yellow fall color

Chlorophyll is the green pigment in leaves. This critically important pigment captures the energy from the sun and uses it to change water and carbon dioxide (CO2) into oxygen and sugars (carbohydrates), i.e. the plant’s energy source for growth and development. In autumn, chlorophyll breaks down faster than it is produced, revealing the other plant pigments and their colors.

A cutleaf weeping Japanese maple (Acer palmatum) bright orange fall color
A cutleaf weeping Japanese maple (Acer palmatum) bright orange fall color

Carotenoids are responsible for the yellow, orange and a few red pigment colors. This pigment is always present in the leaves during the growing season, but the colors become more evident as the chlorophyll breaks down in the leaf. In addition to providing us with a beautiful display, carotenoids protect leaves from harmful byproducts of photosynthesis. Since carotenoids are always present in leaves, yellow, gold and orange colors are least affected by the weather.

Anthocyanins are responsible for most of the red, pink, and purple colors we long for in autumn. Sugars in leaves accumulate as active growth slows down in autumn permitting the production of anthocyanins. These colorful pigments act as an internal sunscreen to protect the photosynthetic system allowing plants to recover nutrients from the leaves more easily as the temperatures decline. What about plants that have no anthocyanin pigments? These plants are usually more resistant to damage from bright light so they have no need to produce these protective anthocyanin pigments.

Tannins are not considered an actual plant pigment, but are responsible for some of the tan and brown colors we see in oaks and beeches in the fall.

Why Do Leaves Change Color?

During the summer, most of a plant’s nutrients are located within the leaves. The shortening of day length and cooler temperatures, particularly at night, signal the plant to begin preparing for winter by transporting carbohydrates (sugars) and mineral nutrients from the leaves to stems and roots for storage in the plant to be reused the following spring. A layer of cells at the base of the leaf stalk (petiole), called the abscission zone, gradually closes off the flow of sugars and minerals into and out of the leaf. In a process called senescence, chlorophyll breaks down causing the leaves to change color and eventually fall off the plant.

Variability of Fall Color and the Role of Weather

Many factors play a role in determining when fall color occurs and the intensity of the color. We cannot predict each summer how the autumn leaf color will be in the landscape. For example, peak (best) fall color can shift by as much as two weeks ahead or behind the normal time peak color occurs year to year based on the weather.

Plant Health and Moisture Levels

Plants that are in transplant-shock (newly planted), drought stressed, nutrient deficient or suffer from insects or diseases may have poor fall color or the exact opposite; they may have better fall color due to increased production of red pigments. Good soil moisture levels throughout the growing season followed by a dry fall can improve the intensity of fall color. On the other hand, excessively wet or drought conditions can cause poor color development. Drought conditions can cause leaves to dry, curl and drop before fall color has sufficiently developed, especially on newly planted material. However, moderate drought conditions may actually improve fall color development in some species, though these same plants may suffer during winter and have dieback apparent in spring.

Temperature, Light Levels and Mineral Nutrition

Cool, dry, sunny fall days with cooler night temperatures stimulate anthocyanin production resulting in bright reds and purples. In contrast, very warm autumn weather may reduce the production of these pigments. During unusually warm autumns, plants may accelerate fall color development, shortening the time leaves remain on the tree or shrub. Early, hard frosts may also severely damage leaves, arresting further fall color development before the brightest colors are revealed. Sufficient sunlight is required for leaves to produce the best coloration. Plants growing in dense shade will usually fail to develop the intense red and orange colors we have grown so fond of each autumn. High soil pH and deficiencies of the various essential mineral nutrients, such as nitrogen, phosphorus, magnesium, iron and high levels of the non-essential element sodium can all affect the intensity of color change in leaves. High sodium soil levels, most likely due to excessive road salt (NaCl) application the previous winter, not only stresses plants and prevents proper water uptake, but also can negatively affect autumn leaf color.

Genetics

Of course genetics play a key role in the intensity of fall color development. This is why some seed produced trees in the forest have great fall color, while seedlings from the same tree may have less intense or even no fall color. This is where plant cultivars come into play. A nursery person will select plants demonstrating superior fall color, improved cold hardiness, increased pest resistance, better growth form, etc. These superior plant choices will often have a cultivar name associated with it. For example, seedling grown red maple (Acer rubrum) will display a range of fall color from green, yellow, yellow-orange, orange, orange-red, red and purple. As gardener, we tend to choose what we like, mostly the orange, red to purple colors. If the plant is not already in commerce, the grower will select the best seedlings for fall color and vegetatively propagate and grow those particular seedlings, offering these new selections to other nurseries or garden centers. It is a win-win for both the nursery and the gardener!

An unknown cultivar of red maple (Acer rubrum) with uniform fall color
An unknown cultivar of red maple (Acer rubrum) with uniform fall color

Laura Jull, Ph.D.

a.k.a.: The “Lorax”