Saturday, March 15, 2014

Looking for Spring Color? Go for a Native Maple

Native maples in their fall glory in GSMNP.
In addition to their fall foliage, maples should
be valued for their early spring blooms.

I love spring!  Signs of life, like buds forming on a tree or sprays of flowers pushing from the cold soil, make me think of the earth yawning, stretching, and rubbing the sleep from its eyes, ready to wake up for another season of growth.  One of my favorite signs of spring is when our native maples (Acer rubrum, A. saccharum, A. saccharinum) begin to bloom.

When many of us think of maples, our minds probably go straight to their spectacular fall foliage.  This is why most of the North American maples in the nursery industry are bred for their autumn color.  Their delicate spring blossoms are often overlooked, but en masse maples in flower can be real show stoppers.

My favorite way to view maples in their spring glory is by taking a long, Sunday drive on a back road.  Last weekend we drove down Route 441 from Townsend, Tennessee to Lake City, Florida.  The whole way down our native maples painted the roadside with sunny limes, yellows, peachy pinks, and bold scarlet reds.  Over the next month, whole mountain sides in the Great Smoky Mountains National Park will be dotted with the colors of maples in bloom. 

A cluster of maple inflorescences
Some specimens produce bolder, showier blooms than others.  Maples can bloom as early as January or as late as April.  Flowering in maples is both a response to environmental conditions and a function of genetic predisposition.  Genetic variation is responsible for inconsistency in blooming, which causes stands of maples in the wild to produce a smattering of blooms throughout the spring.  Although nursery breeders seek to control the genetic qualities of the maples they produce, flower time and quality is often an afterthought.  This means that maple flowering in the landscape can be just as inconsistent between two plants as in the wild.

When in flower, our North American native
maples can be just as showy as many
of the more familiar spring blooming trees

Unlike other spring flowering trees that are pollinated by bees and other insects (such as cherries, dogwoods, and redbuds) maples are wind pollinated. The earlier maples are able to blossom, the fewer barriers there will be to pollination.  For example, if a maple flowers in January, none of the other trees or shrubs have leafed out yet, so the pollen can travel unhindered from one flower to another.  This can be a risky move, because a cold snap can damage flowers and samara development.  On the other hand, if a maple flowers in April there will be less danger of cold damage. However, many other trees in the landscape may already have foliage, preventing how effectively wind can carry the pollen between flowers. 

Those who want to enjoy the spring blossoms of maples in the comfort of their own landscape may be in for disappointment.  As stated earlier, the industry doesn't currently breed maples for flower quality.  Strong, handsome maples that provide beauty, shade, and vibrant fall color may also produce lackluster blooms.  However, there are a few things you can do to improve your odds of finding a maple that will add stunning spring blooms to your landscape:

  • Consider a red maple (Acer rubrum) - Red maples purchased from a reputable nursery don't just produce red fall foliage (although many may also have yellow, green, and orange fall color).  Red maples tend to also generate scarlet inflorescences.  To quote Dr. Michael Dirr in his Manual of Woody Landscape Plants (1998), A. rubrum's "red, rarely yellowish" spring blooms may be composed of mostly pistils, stamins, or they may be monoecous, but "all are showy".
  • Buy local - This tip doesn't just mean you should support your local garden centers (which is always a good thing to do!).  Maples grown in your area are more likely to perform well in the long term and endure in the landscape than maples grown in another region of the country.  This is especially true for folks up north -- although maples grown in the south may be the same species as the maples native to your area, they typically aren't as cold hardy.
  • Avoid grafts? - If you're looking for a Japanese maple (A. palmatum), a graft is a must.  However, there are mixed reviews of how grafted red maples perform in the long run.  Dirr (1998) noted that grafted native maples tend to not perform as well long-term as maples grown from cuttings, tissue culture, or seed.  Remember, seed-grown plants may last longer than a maple grown from a graft, but with the genetic variation of seed-grown plants you never know what you're going to get.  On the other hand, Matt Nichols of Mr. Maple has successfully grafted red maples and has grafted sugar maples.  It would be a good idea to do some investigating and buy from a quality nursery.

Thank you to Garden Talk on Knox Talk 94.3 FM for inviting me on to present their plant of the week this morning!  If you're wondering, the featured plant was Acer rubrum.  To read more of my favorite plants, be sure to follow me on Plante on Plants.  To tune in to more gab from the garden gurus, stream Garden Talk live online on the Knox Talk website.

If you have any questions, ideas or suggestions, please feel welcome to post a comment below or to send me an email.

What are some plants that shout SPRING to you?  What's your experience with our native maples?  What are some other overlooked spring bloomers?


The delicate flower buds of Acer rubrum
Acer rubrum in bloom
A hybrid maple, Acer x freemanii, makes an attractive street tree on the University of Tennessee's Agriculture campus.

Friday, November 1, 2013

Candy Corn Plant

The blooms of Candy Corn Plant resemble the staple
Halloween candy "candy corn"
It's officially halloween weekend, and I can't think of a more fitting plant to write about than Cuphea micropetala, commonly known as candy corn plant.  The common name is derived from the fact that the fall blooms closely resemble the staple halloween candy "candy corn".  In Knoxville, this Cuphea is at the height of flowering the week of the haunted holiday.

Candy corn plant is a hardy annual / tender perennial in zones (7)8-10, and is grown as an annual in cooler climates.  The glossy green foliage is evergreen in areas where this plant returns perennially.  Site in full sun for best performance.  Candy corn plant prefers moist but well drained soil.  In Knoxville, I haven't seen this plant get much larger than 3 feet tall and 3 feet wide.  I've read that 'David Verity' is a good selection, but haven't seen it in cultivation.

The showy blooms aren't just attractive to gardeners -- butterflies and hummingbirds find the flowers irresistible as a source of nectar.  As a student intern at the University of Tennessee Gardens perennial border, I once watched several hummingbirds wage full out battle over who had the rights to our specimen of C. micropetala.  In my experience, sulfur type butterflies seem to prefer this plant as a food source more than the showy swallowtails or monarchs.

C. micropetala is an underused plant, especially in my region of the country.  I've only seen this plant in a handful of gardens, and only as a single specimen.  I'd love to see this plant en masse in a variety of landscape situations.  If you're in zones (7)8-10, right now or later in April would be a great time to plant candy corn plant.  For folks who garden in a cooler climate, wait until spring when the danger of frost has passed.

The photos for this blog are courtesy of the undergraduate teaching assistants for UT's course Plant Sciences 220: Landscape Plant ID I.  They upload tons of wonderful photos as a study aid to the class Facebook page.  The photographer was TA Austin H.

If you have any questions, ideas or suggestions, please feel welcome to post a comment below or to send me an email.

What are some other good plants for a halloween themed garden?

What's your experience growing candy corn plant?  How has this plant performed in your garden?


Mature selection of Candy Corn Plant from the UT Gardens

Thursday, August 1, 2013

Illuminate Your Landscape with Golden Boston Fern

The chartreuse foliage of this variety of
Boston fern illuminates a shady situation
at the UT Gardens in Knoxville.
As an apartment dweller, my landscape is limited to window boxes, patio plants, hanging baskets, and interior plants.  My favorite annual landscape plant this year has been the golden Boston fern.  The fine, chartreuse foliage of this Nephrolepis exaltata has illuminated my shady porch in a way that a typical green Boston fern just can't.

A Multitude of Uses

  • This variety of fern has thrived in a container on my patio, a hanging basket, and even indoors in my tabletop aquaponic system.  
  • In the past, the golden Boston fern has grown excellently in a couple of living wall systems that we demonstrated at the Southeastern Flower Show.  
  • This variety of fern performs really well in a summery mixed container.  Partner with pink flowers or purple foliage for a color combination that really pops.  Mixing with the bold texture of a Caladium or a shade tolerant elephant ear will make this plant's feathery foliage stand out.
  • My favorite use of this versatile tropical is as an annual in the shade garden.  The brilliant foliage really shines a little light in a shady situation.  
A sprig of this golden Boston fern has really
taken to life in my home aquaponic system.
Preferred Conditions

Golden Boston fern prefers dappled shade.  Full sun will burn this fern's sensitive foliage.  Keep soil moist but well drained for best growth.  This tropical annual won't overwinter in anything less than USDA Hardiness Zone 10a.  Your local garden center or plant nursery should carry this variety of fern.  If they don't, I'm sure they'll be happy to order it for you.  You can also order by mail from Randolph's Greenhouses

Origin

The chartreuse variety of Boston fern was first discovered by Jason Reeves, the curator at the University of Tennessee trial gardens in Jackson, TN.  Rita Randolph of Randolph's Greenhouses shared the plant with Allan Armitage, former director of the University of Georgia Trial Gardens in Athens.  Armitage named the plant 'Rita's Gold', and the variety went on to win the Classic City Award for its performance in the landscape.  

I've pieced together the humble beginnings of this particular fern based on conversations with horticultural experts and online research.  Please don't hesitate to shoot me an email if there's anything that should be added or modified.

To see more of my photos of the versatile golden Boston fern, be sure to check out my flickr set.

If you have any questions, ideas or suggestions, please leave a comment below or shoot me an email.

How has this golden Boston fern grown for you?  What tropical annuals have thrived in your garden this summer?  What plants do you use to illuminate your landscape?

Splashes of gold brighten two of the interior living walls highlighted at the Southeastern Flower Show in Atlanta, GA and the Dogwood Arts Home and Garden Show in Knoxville, TN

Monday, April 8, 2013

Quick and Dirty Tips for Pruning Trees

Pruning trees is a must for good aesthetics and tree health.  Clearing some space in the canopy helps
Pruning a peach tree this February.
increase air circulation, which can be good for decreasing some pest, disease, and fungal problems.  Cutting out crossing limbs can cut down on damage caused by rubbing branches.  It's easier to see the form of a well pruned tree, which makes it much more attractive than a big blob of green foliage.

Although some trees prefer to be pruned in the spring or summer, most should be pruned in cooler fall or winter months.  In Knoxville it's about time to wrap up last minute pruning in preparation for spring weather.  Cooler zones further north may have a bit more time to prune.  Tree health aside, one major benefit of pruning trees in the dormant season is that there's less foliage in the way.  To quote Dr. Susan Hamilton of the UT Gardens, it's easier to see the "bones" of the tree if you prune in the winter.

Below are a few best practices I follow for tree pruning.  This is a far cry from a comprehensive guide, and if you want to learn more there are several good guides available.

Cut it out:

  1. Dead / broken limbs:  These branches are goners.  There's no point in leaving them in, so take 'em out.  If you think the limb could have possibly died from a pest or disease problem consider cutting at
    Image courtesy of www.wintergreenhouse.com
    least 6 inches below the start of limb death to root out the problem.
  2. Suckers:  This means any growth from the base and the trunk.  Suckering is especially prevalent with grafted trees, which makes it a common occurrence in the landscape.  Aesthetically, suckers are distracting.  Horticulturally, suckers may be sprouting from the rootstock instead of the desired graft.
  3. Water sprouts:  I.E. vertical branches.  Water sprouts are weak growth and should be removed earlier rather than later.  The bigger they get, the more they rip.  
  4. Crossing limbs: These limbs will rub against each other and damage the bark making the tree more susceptible to pest and disease problems.  In addition to removing limbs that are currently intersecting, go ahead and cut out the ones that will cross in the future.  Follow the growth of a branch.  If it continues growing in the same direction, where will it end up?  If the branch is growing toward the center of the tree instead of out, it's pretty well guaranteed to cross sometime in the future.
  5. Hangers:  In many cases, if a limb is droopy it may become weak and break.  Keep an eye out for hanging limbs and remove them if you think they'll become a problem.
A few more Tree Tips:
  • Trees should be pruned regularly -- about once a year.  Annually going through and chopping out problem branches while they're small is healthier for the tree and easier work than waiting until the problem branches are large and heavy.
    It's a good idea to sterilize pruners with
    hydrogen peroxide between plants or diseased limbs.
  • Cuts should be made at an angle.  That is, the stub shouldn't be flat upwards like a table.  An angled cut will drain water, a flat cut will pool water and develop health problems.
  • Use a bypass pruner.  Bypass pruners will make a clean, healthy cut.  Anvil pruners kind of squish the limb before cutting.
  • If the branch is too large for a set of bypass hand pruners, step up to loppers.  If the branch is too large for loppers, use a hand saw.  If the branch is too large for a hand saw, consider calling a professional.
  • Use sharp tools.  Sharp tools are easier to use and make cleaner cuts.
  • Sterilize tools with hydrogen peroxide.  I pour peroxide in a little spritzer bottle and keep it on my person while I work to sterilize between trees or when pruning a specimen that has a particularly nasty disease issue.
Remember, pruning is always thoughtful and never reckless.  Fight the temptation to chop at the canopy with hedge clippers or a chain saw.  Although good pruning may take a little more effort, you'll have the best looking trees on the block.  And remember, "Topless Trees are Indecent!"

If you have any questions, ideas, or comments, please don't hesitate to leave a comment or send me an email.

To see more of my tree maintenance pictures, check out my photobucket story.

What words of wisdom can you share about pruning trees?  What are your favorite tools for getting the job done?  Any good stories or experiences?

Pepe and I prepare to trim up his orange tree.
Pruning the tree opened up the canopy and made the attractive form more visible.

Monday, March 18, 2013

Quick and Dirty Tips for Tree Planting

I apologize for falling behind on blogging.  School this semester has not left a lot of free time for writing, but I do want to continue with regular posts.  So, in the spirit of brevity, please enjoy the following quick and dirty tips for planting trees.  Stay tuned for the quick and dirty tips for pruning.

Timing is Everything
Cool winter months is a great time to plant dormant trees and shrubs.  Without the burden of green foliage that requires a constant flow of water, woody specimens are able to develop a healthy root system.  The earlier in the winter that you plant your trees, the more time their roots have to develop, and the better prepared the trees are to withstand summer heat.  In Knoxville, March is about the latest that I would recommend planting trees and shrubs.

A "bare root" tree is exactly what it sounds
like -- there is not soil around the roots.
Container or Bare-Root?
Many homeowners buy trees and shrubs grown in containers from a nursery or box store.  While I am all for supporting your local nursery, I prefer to plant "bare root" woody specimens.  Bare root plants are exactly what they sound like -- there is no soil around their roots.  In my experience, bare root trees and shrubs are less expensive, establish faster and perform better than container grown plants.  Bare root specimens can be ordered through the internet or catalogue from a reputable source.  Ball and burlap is another option as well.

Eliminate the Competition
Although most weeds in and of themselves may not be a threat to successful growth of trees and shrubs, their presence near the trunk is undesirable for a couple reasons.  Aesthetically, you may not want weeds cluttering up the "drip zone," or area beneath the foliage of your tree.  If the tree is to be planted in an area that is mowed regularly -- like the front yard -- if there are weeds and grass growing near the trunk you may risk having your tree damaged by a weed eater or lawn mower.  For these reasons, it is a good idea to use your shovel to remove existing weeds and grass from the area around your tree prior to planting.

Make sure your hole is at least big enough
to hold all of the plant's roots.
Dig Baby, Dig
If your tree is a container tree, make sure your hole is at least bigger than the plant's container.  Some people suggest digging a hole that is twice as wide.  I haven't noticed much of a short or long term difference between the growth of trees that were planted in sufficient size and larger holes.  If you are planting a bare root tree or shrub, make sure the hole is large enough to sufficiently hold all the roots.

To Amend or Not to Amend
Some people amend the soil in the hole with potting soil, good topsoil, sand, compost, or fertilizer.  I like to think of it this way -- in a year, your tree's roots are going to expand far beyond that zone.  Why put off the inevitable?  In some cases, amending the soil can actually hurt the tree's development.  For example, if a heavy clay soil is amended for a tree, the slow draining clay can create a basin that holds water around the tree's roots and causes them to rot.  However, if you are growing a tree or shrub that has a specific soil pH (acidity or alkalinity) requirement, the soil will need to be amended with sulfur to lower pH and make more acidic or lime to raise pH and make more alkaline in order for the tree to grow properly.

Look for the "root / shoot" junction before
planting your tree.
Look for the Root-Shoot Junction
There have been times when I've planted a tree and a year later it dies inexplicably.  My sleuthing did not turn up any fatal pest or disease problems.  The cause of the tree death was actually being planted too low or too high.  Now when I plant trees, I keep my eyes peeled for something called the "root / shoot junction."  Look on the trunk of your tree for the spot where the roots become the roots and the shoot becomes the shoot.  When you plant your tree, make sure the roots are below ground and the trunk is above ground.  Most of the time, the soil line of container grown trees is already at the root / shoot junction, but double check to be sure.

Add Mulch
Mulch is important for weed suppression, protecting the trees from lawn mower or weed eater damage, and just plain old looks pretty.  For new beds, add about 3 inches of mulch under the drip zone of the tree.  After mulching, be sure to pull the mulch away from the trunk of the tree.  Be sure to avoid the "mulch volcano" look -- that is not attractive and it is unhealthy for your tree.

Thanks for reading and stay tuned for the quick and dirty tips for pruning, hopefully coming up soon!

If you have any questions, ideas, or comments, please don't hesitate to leave a comment or send me an email.

To see more of my tree maintenance pictures, check out my photobucket story.

Do you prefer container trees or bare-root?  What tips and tricks have made your trees and shrubs grow successfully?


The Knoxville Botanical Garden and Arboretum's "Every Child Outdoors" Fruit Grove

Wednesday, January 2, 2013

Pony tail palm, a living statute that adds interest to any residence

A large Beaucarnea trunk surrounded by tropical foliage
at Nashville's Opryland Atrium, 2010
When the garden slows down in the winter, many gardeners turn their attention to their houseplants.  If you're anything like I am, caring for a green, living houseplant is like a form of gardening life support -- it keeps me focused through the winter.

One of my favorite interior plants is Beaucarnea recurvata, more commonly known as pony tail palm or elephant-foot tree.  The pony tail palm can develop lovely curly foliage that cascades over the edge of whatever piece of furniture it's sitting on.  The trunk has a nice gray bark, and the base of the plant will swell creating a bottle-neck appearance.

Pony tail palms are extremely slow growing, but given time a tree can reach 30 feet in height.  Beaucarnea recurvata prefers a high light situation when
I strike a pose with a large pony tail palm in
 Nashville's Opryland Atrium, 2010.
grown indoors, and will grow best by a sunny window.  Native to the deserts of the North American South and South West, pony tail palm does not require a lot of water.  The base of the plant actually serves as a water reservoir.  To prevent over-watering, I tend to wait until the base starts to get a puckered, wrinkly appearance instead of watering when the soil is dry.

Small specimens can be purchased from a local garden center, box store, florist, or grocery store.  Between the low maintenance requirements and statuesque form, pony tail palm is a great choice for any residence.

If you have any questions, ideas, or suggestions, leave a comment or shoot me an email.

How has pony tail palm grown for you?  What's your favorite interior plant?  How do you beat the winter blues?


My small pony tail palm serves as a living statute in my residence.

As seen from this specimen grown in Nashville's Opryland Atrium, pony tail palms can be multi-stemmed.

Friday, December 14, 2012

Tomatoes in December? Grow the Gift of an Edible Ornament

I love the holidays.  Every December I look forward to all the Christmas trees, wreaths, cookies and ornaments   But holiday traditions don't have to be so... traditional.  If you want to give a gift with WOW factor this year, consider the 'Sweet n' Neat' tomato.

'Sweet n' Neat' Tomatoes make a
lovely, living edible ornament
'Sweet n' Neat' tomatoes are a compact variety that is content to grow on a sunny windowsill.  These edible ornaments will brighten any home or office with small red, scarlet, or yellow cherry tomatoes -- even during the winter.  Pot size isn't a major issue for 'Sweet n' Neat' -- I've heard of instances where this variety has developed fruit while still growing in the small nursery cell pack weeks before a sale.

I first heard of this variety while attending the Perennial Plant Association's 2012 symposium.  In the talk "Food for Thought, Edibles in the Landscape," Lloyd Traven of Peace Tree Farm shared his edible ornament idea with the audience, and he suggested 'Sweet n' Neat' as a good variety for the concept.

Working with Knoxville's Austin-East High School, we grew 200 edible ornaments as a fundraiser for their garden program.  There was immediate and intense interest!  This has been a very popular concept for a plant sale, and I'd definitely recommend other schools that have access to a greenhouse try this in the future.

A rosemary tree is another edible
and living holiday gift idea.
If you're looking for some seed for your home garden, there are many websites that offer yellow, red, and scarlet fruiting 'Sweet n' Neat' tomato seeds.  If you intend to grow the plants for a fundraiser, there aren't many retailers that currently sell this variety in bulk.  However, 2B Seeds does sell all three colors of 'Sweet n' Neat' in quantities of 100.

This variety may not be available from a big box store, but check with your local garden center to see if they carry any.  If not, suggest they grow some for the next holiday season!  Knoxvillians can pick up their edible ornaments by contacting myself or the lead teacher of Austin-East High School's garden program.

A rosemary tree makes another lively holiday gift.  Consider purchasing from a good local nursery instead of the grocery store or a big box store.  Rosemary grown at a local nursery is more likely to have been properly cared for and will make a more healthy gift.  In my experience, grocery chains and box stores tend to over-water their rosemary trees, which can result in an algae-ridden, smelly plant that has root rot (and who would want that?).  Be sure to inform recipients that their rosemary probably won't be hardy enough for life outdoors, and will enjoy spending chilly winters inside or in the garage.

Add a festive, living gift to your holiday traditions.  The gardeners on your Christmas list will be glad you did!

If you have any questions, ideas, or suggestions, leave a comment or shoot me an email.

How do you incorporate gardening into your holiday traditions?  What are your experiences with growing 'Sweet n' Neat' Tomatoes or rosemary trees?