Plant Preview


Welcome to Plant Preview, a blog dedicated to helping gardeners learn about gardening techniques and preview new plant cultivars. Read about new plants here first and hear how your "comrades in compost" are making use of new plant introductions in their gardens and landscapes. Blog author Geri Laufer is a life-long dirt gardener, degreed horticulturist, author and former County Extension Agent. Plant Preview is copyrighted by Geri Laufer.

Monday, January 10, 2011

Benefits of Snow on Gardens and Plants


It’s January 10 in Atlanta and there are 6 inches of snow frosting the table on my deck(!). Daily life and activity have come to a standstill, schools and shops are closed, and although the State DOT brought extra crews up from South Georgia, we are warned to “stay off the roads.”  I thought I’d take a look at the effects of snow on gardens and plants.

On the plus side, the fluffy white stuff benefits plants by acting as an insulating blanket that protects landscape plants from the effects of freezing and thawing during freezing winter weather. The insulating effect is due to the unique configuration of snowflakes that includes small spaces within their structure that are filled with air, resulting in low heat conductivity. As a result, the daily temperature penetration into the snow is reduced and plants are protected from really cold dips in temperature.  Flower bulbs, veggie root crops and even the crowns of dormant perennials benefit from this insulating layer of snow.

Without insulation, the water in plant cells is more likely to freeze, damaging cell walls. Frost-damaged plants are easy to spot; their growth becomes limp, blackened or takes on a translucent appearance. Evergreens turn brown. Frost problems are often exaggerated where plants face the morning sun, since this causes them to defrost too quickly, rupturing their cell walls. Snow cover mitigates these problems.


Another positive effect of snow cover is to bring otherwise shy birds right up to the doorstep.  We tossed some dark pumpernickel bread crusts onto the deck; now they are gone and a group of sparrows left their little tracks in the snow.


On many soils the gradual freezing and thawing improves the physical structure of the soil.  Chinese researchers led by X Deng at the Chinese Agricultural University in Beijing studied The Effects of Frost Action on Soil Physical Properties of Plough Pan. Undisturbed soil cores of loamy clay were subjected to freezing and thawing in lab, and the results indicated that this action “significantly reduced the bulk density of plough pan and increased its porosity and hydraulic conductivity.” Lighter, more porous soils are easier for roots to penetrate, yielding better plant growth in the growing season.

In Atlanta usually the snow doesn’t stick around long enough to act as a blanket for very long and I haven’t owned a snow shovel for 20+ years. In fact, I can only remember one winter back in the early 90s where the top few inches of soil actually froze. So another plus is provided when the snow melts, providing added moisture that’s good for plants.

According to Taylor’s Encyclopedia of Gardening, snow is called “the poor man's fertilizer.” As it falls, a small amount of atmospheric nitrogen and sulfur are attached to the snowflakes and sleet particles.  When the snow melts it releases that nitrogen into the soil. Hardy plants green up because unfrozen ground is warm enough that growing plants can absorb this nitrogen.

Snow can be both friend and foe. A heavy layer of wet snow can cause branches to bend, break or split, and plants to uproot or fall. The Tree Care Industry Association suggests shaking excess snow from the branches of large trees, shrubs and hedges, to prevent them from becoming disfigured by the weight, particularly from broad leaf evergreens. It’s only common sense to remove heavy deposits of snow from the roofs of greenhouses and cold frames to let in light and prevent the structures from bending under the weight. 

Is it snowing where you live? 

Photo Credits: David Laufer, NikonJim

Friday, January 7, 2011

Why and How to Prune Shrubs


It is winter and the leaves are gone, making it easy to see the structure inside deciduous woody ornamental shrubs. Three reasons shrubs are pruned are to:

+ keep them shapely

+ encourage better quality blooms by reducing the amount of wood so energy is diverted into the production of fewer but larger flowers

+ maintain plant health by eliminating dead, dying, or diseased wood, possible entry points for insects or diseases 

I’m not talking about “shearing” as is done with a dense, solid, usually evergreen hedge. Nor is pruning the best way to keep a shrub “short”.  For that, [hopefully] the initial plant selection considered the location and the ultimate height of the shrub. Only last night  I remarked at our car repair shop that they were going to be involved in a lot of pruning based on the five red-leaved Loropetalum newly planted beneath a low picture window. Each plant alone has the potential to obliterate the entire window, reaching over 10 feet in height! It looks like constant pruning is going to be necessary, when the choice of a dwarf-growing variety would have eliminated this maintenance issue.

A shrub is defined as a woody plant having multiple trunks or woody stems arising from the base at soil level. Sometimes these get too crowded, with criss-crossing stems inside the shrub. Pruning allows air to circulate within the crown and the leaves to dry off more quickly after dew or a rain. 

Then there is the spring-blooming and summer-blooming controversy. Now, it’s true, pruning a spring-blooming shrub in late winter means that some of the flower buds which formed last fall will be removed, reducing the overall number of flowers to be enjoyed. However, I think the benefits of being able to see the plant’s multi-stemmed structure while the leaves are off compensates for this reduction of flowers, and will certainly be justified next spring.

Armed with sturdy gloves and sharpened  by-pass pruners: 

+ First, trim away any branches that are rubbing against others

+Next, prune branches that are growing toward the center of the shrub, allowing outside branches to flourish

+Finally, remove stout branches of old wood at the soil line, leaving vigorous young branches that will grow, flower and restore a youthful habit to old, overgrown shrubs

I like to prune toward the end of winter, so I'm putting it on my gardening calendar for late February. This way I can observe any winter kill and prune accordingly. 

Drawings courtesy qwickstep.com, Virginia Tech Extension, photo Garden Debut(R) Admiration Barberry PP16921


Thursday, December 30, 2010

20 Gardener's New Years Resolutions


Resolved

I resolve to garden more

I resolve to lay out a master plan with the help of a landscape architect

I resolve never to pass up a new plant I see in a nursery or garden center

I resolve to dig the holes before I go to the annual herb plant sale

I resolve to weed religiously

I resolve to reorganize my tools

I resolve to rescue plants from markdown racks at big box stores because I have green fingers

I resolve to get timers for both hoses

I resolve to plant 1000 daffodil bulbs per year

I resolve to plant every plant I purchase immediately after I get home with all of them

I resolve to weed occasionally

I resolve to re-read the gardening books I already have

I resolve to divide my hostas

I resolve to sharpen my ratchet lopers

I resolve to mark where the bulbs come up this spring so next fall I won’t plant over top of them

I resolve to try some new yuccas

I resolve to weed if desperately needed and I can't get out of it

I resolve to clean my spade and garden fork after each workout

I resolve to make friends with the Chipper/Shredder Tree Guy who has free woodchips for mulch


I resolve not to buy any more plants unless I know specifically where I will plant them in the garden. Ha


20 Gardener's New Years Resolutions

Monday, December 27, 2010

Top 10 Tips to Recycle Christmas Trees



When you are finished with your cut tree don’t throw it away; recycle it!  Here are some tips on alternative options for what to do with your tree after the holidays.


Tips on Re-using the Christmas Tree


1.         “Win one for the Chipper”. Mulching programs are a fast-growing trend in communities across the nation. Large chipper/shredders are used to grind up the trees, and afterward the mulch is made available for use in residents’ gardens. Municipalities or sometimes Tree Companies or Big Box Stores garner good will by contributing to this effort. Make sure the tree is cleaned of ornaments, hooks, tinsel, garlands, etc. and drop it off at a yard to be chipped. Or ask a buddy. Long ago my husband bought me a shiny red chipper/shredder for a Valentine’s present, and I chip our tree and am willing to help out a couple of neighbors each year.


2.                  Bottle Trees. Old Christmas Trees are the perfect vehicle for creating some yard art. Using sharp bypass pruners or ratchet lopers, clip branches off at about 6-8 inches out from the trunk, eliminating those that are not spaced evenly around the trunk by cutting flush. Anchor the tree upright in the ground then mount your collection of long-neck colored glass bottles on the branch-stubs for a down-home style garden ornament that looks well as the sunlight sifts down through the glass. Use the branches that were removed to loosely cover tender perennials, leaving plenty of air surrounding the crowns. 

          
3.       Wildlife Habitat. The National Wildlife Federation suggests that wildlife need places to hide in order to feel safe from people, predators and inclement weather, and awards Certified Wildlife Habitat registration to home landscapes that fulfill many needs.  Brush piles and dead Christmas trees are perfect hiding places. Lay the tree down in an out of the way area of the garden, perhaps near the wood pile or under cover of other evergreens to invite wild creatures to live at your home. 


4.         Bird Feeders. After removing all decorations prop the dead Christmas tree in a corner of the garden and use it as a bird feeder and sanctuary. Hang with suet feeders, fresh fruit like orange or grapefruit halves, popcorn garlands, or seed feeders for thistle, black oil sunflower and millet seed.


5.     Call in the Cavalry. Telephone for an appointment to have the Boy Scouts or an environmental  non-profit group in the area pickup the tree and recycle it in return for a small donation (in the $5 range)  


6.     Barriers to Soil Erosion. Turn old trees into soil erosion barriers on river banks and lake shorelines. Use as beach stabilization to protect sand dunes and preserve beaches. Use dead trees as filters to manage delta sedimentation.  


8.          Fish Feeders. Back when we lived on a property with a half-acre earth-bottom pond, I submerged old Christmas trees in the deep end to make a fishy refuge, egg-laying habitat and feeding areas for the bream, catfish, bass and bullfrogs to escape the alligator snapping turtle living there.  


9.      Be Crafty. Strip fragrant spruce or pine needles and put them in tiny cheesecloth drawstring bags to sweeten your next hot bath. Let the hot incoming water rush over them to make a fragrant soak. Or add a few to the dog's bed or hamster's cage to add a fresh, clean pine-y aroma. 
      
10.       Use mulch to pave Hiking Trails or Woodland Walkways. Parks, nature walks and larger properties use shredded evergreen trees as a free, renewable path material that is agreeable to the environment and cushions the steps of walkers and hikers! 


·         As a Last resort: put the tree out on the curb. <<>> the solid waste removal guys might the tree away. Many areas collect trees during regular pickup schedules during the two weeks following Christmas, although there are often requirements for size, removing tinsel, ornaments, limitations on flocked trees, and so forth. Chop the tree into 3 or 4 foot sections for easier removal and put it with the green yard waste container.

Living, rooted trees. To avoid recycling issues, next year choose a living, rooted (container-grown or ball and burlapped) tree and then plant it in your landscape after Christmas. See the Dec. 11 Blog that discussed plenty of options for choosing a living trees. Pre-dig the hole while the soil is still soft before the ground freezes, then plant the tree immediately after Christmas, and remember, living trees have a better survival rate in mild climates. 

For Safety's Sake cautions people: do not burn a tinder-dry tree that is full of resin and apt to go up in an uncontrolled whoosh; not in the fire place and not even outdoors. 

Thank you for the photos. 
Photo Credits:  Bottle Tree, http://selmaala.blogspot.com; Chipper, tractorbynet.com; Natural Muslin Cloth Bags, www.etsy.com

Monday, December 20, 2010

Winter Solstice, Full Moon, Lunar Eclipse and Plant Photoperiodism


And now for something completely different due to the season of the year! I am fascinated by the heavens. As the days grow shorter and shorter and winter approaches, astronomers tell us the Winter Solstice arrives at 6:38 EST on Dec. 21, 2010. This is the shortest day and the longest night of the year.

In the early evening the maximum tilt or declination of the North Pole away from the Sun (its axis is 23.7 degrees away from the vertical) will begin to reverse itself as the Earth begins to shift on its axis, and as the planet "straightens up" the days in the Northern Hemisphere will begin to grow longer in anticipation of summer. 

December 21 is the turning point when the days begin getting longer again, so it has been celebrated as the ‘return of light’ since the Stone Age. The famous site known as Stonehenge in England has standing stones arranged to pin point the last rays of sunshine at sunset on the Winter Solstice, an event that was seen as the reversal of the sun’s ebbing presence in the sky and the rebirth of the year.  Originally, the burning of the Yule log was significant during the Winter Solstice, representing the return of the light, and eventually becoming a well-loved Christmas tradition.

Living organisms are affected by the day’s length. During those short winter days, people can experience SAD or Seasonal Affective Disorder, also known as the winter blues, which is treatable with bright light therapy and other strategies.

Plants respond to day length in more direct ways. Photoperiodism is the term used to discuss plant responses to day length or more accurately, night length.  “Short day plants” flower as the days grow shorter during late summer and fall (a couple of examples are goldenrod and chrysanthemum). Well-known as a Christmas flower, the poinsettia develops its showy bracts as the year approaches the Solstice, while the day length is decreasing and there are a long, unbroken periods of darkness each night.

Other plants (like clover, foxgloves and garden pinks) are called “long day plants” because they bloom as the days get longer and the nights are short. Still others are “day neutral  plants” because they are less responsive to the length of the daylight period. Spring and Fall Equinoxes are the midway point of the solar year.

This year in addition to the Winter Solstice, two other celestial events will occur on December 21: a Full Moon and a Lunar Eclipse! The Moon’s orbit will take it to the far side of the Earth, positioning Planet Earth between the Sun and the Moon, and causing the Earth’s shadow or umbra to fall on the face of the full moon and turning it a dark copper or brown color for a few hours.



According to NASA, here’s a Time Table for these occurrences:  

Early morning Dec 21 1:33 am EST         Full Moon begins to enter Earth’s shadow
Early morning Dec 21 2:41 am EST         Moon will be completely eclipsed
Early morning Dec 21 3:53 am EST         Moon begins to come out of the Earth’s umbra
Early morning Dec 21 5:01 am EST         Moon is fully visible
Morning Dec 21 7:34 AM EST                   Moonset/ Daylight
Early Evening Dec 21 5:25 PM EST         Moonrise-- Full Moon  
Late night December 21 6:38 pm EST     Winter Solstice; Earth begins to change the tilt on its axis, moving the northern hemisphere toward the Sun  

Dear Readers, All good wishes of the season from gardengeri

photo credits: Stonehenge: Auburn.edu; moon during eclipse: AIP.org  Thank you

Wednesday, December 15, 2010

10 Tips How to Protect Plants When Cold Temperatures Blast


Garden Strategies Once Freezing Temperatures Have Arrived 
Gardeners know that windy cold with a sudden plunge in temperatures, sometimes prolonged over several days, makes plant protection difficult. In meteorologist lingo, “the Jet Stream is blasting south, bringing frigid air masses from polar regions” and this is called an “advective freeze“. 

How To Protect Plants
1.      
A   Tip 1.  Add mulch to protect the roots. Apply organic mulch anytime to insulate shallow roots by reducing temperature fluctuations. Most woody ornamentals and perennials are root hardy, so use a layer of mulch to protect the crown and the root zone despite the fact that foliage may die back to ground level. Evergreens and newly transplanted plants especially benefit from a thick layer of mulch around their bases insulating the soil and allowing them to take up moisture despite periods of cold weather and avoid dehydration.

2.    
          Tip 2. Drape burlap, canvas, old quilts or sheets, large cardboard boxes, or floating row cover fabric over plants for the duration of the cold spell for three reasons:

a.      to slow wind movement;
b.      to protect from frost; and
c.       to shade from early morning sunshine that can be devastating to frozen leaves.

NEVER use plastic to cover plants;  not clear plastic, not black plastic, and not white plastic. Plastic traps solar radiation and causes a buildup of moisture underneath. If plastic is not removed at dawn (and who is going to do that?) the sun’s rays cause heat build-up and frozen plant tissue bake inside the tent.

3.      Tip 3. Blankets do not provide “warmth” unless an incandescent light bulb or a string of Christmas lights is added inside the covering. Choose extension cords labeled for outdoor use. New LED lights don’t work to add heat. 

4.      Tip 4. Happen to have a cool greenhouse handy? Lucky! Tender plants grown in pots can be moved inside during bad weather. Or take cuttings of those that cannot be grown in pots and overwinter these in a warm greenhouse or on a windowsill, ready for planting in spring.

Without a greenhouse, move hardy container plants under a protective roof like a deck or porch, and group them together to increase their protection.

5.      Tip 5. Use windbreaks like fences, walls, tree canopies or the sides of buildings to protect container plants that can’t come inside. Coverings include frost cloth, sheets and quilts, plastic, cardboard panels or large cardboard boxes, and lean-tos propped against the wall.  

6.      Tip 6. Consider building a quick-frame to provide additional protection for favorite or newly transplanted ornamentals. Drive stakes into the ground around the plant(s) then drape canvas over the stakes, making sure it reaches to the ground. This provides air flow and ensures the cover does not have direct contact with the leaves, since touching can injure the foliage.

7.      Tip 7. Home gardeners: DO NOT try to use water as cold protection! Commercial agricultural enterprises sometimes use water from a sprinkler system to coat strawberries or citrus fruits. The idea is to keep the leaf surface temperatures near 32°F (0°C) because sprinkling utilizes latent heat released when water changes from a liquid to a solid state. But sprinkling must begin as freezing temperatures are reached and continue until thawing is completed. Water must be evenly distributed and supplied in ample quantity to maintain a film of liquid water on the foliage surfaces, possibly for days.

Although commercial farms uses sprinkling for cold protection, residential sprinkler systems do not have the flow volume to protect plants this way. Too much water can cause disease, plus the sprinkler itself can freeze up. As a result, cold damage to plants from inadequate amounts of irrigation water may worse than if nothing was done at all.

8.      Tip 8. Move container plants to a shaded location to avoid morning sun hitting them. Lift pots and containers and place on lumber or 'pot feet' to prevent waterlogging. Insulate above-ground pots with a layer of bubble wrap or hessian to prevent them freezing and cracking and ensure plant rootballs stay healthy.

9.      Tip 9. For those guilty of stretching the Climate Zone envelope. Cover is especially beneficial for borderline tender plants that the gardener just had to give a try. The ever-increasing number of tender plants available may not withstand sustained cold without some form of protection. Hardy Tropicals may fit this description. Recent transplants are good candidates for protection, because they may not had enough time to establish strong root systems. 

      Tip 10. Water when there is a slight break in the freeze to maintain soil moisture, but do not overwater. Watering melts frozen soil or container potting mixes and lets plants become re-hydrated. 

Saturday, December 11, 2010

To Choose a Living Christmas Tree, Think Outside the Box!


Purchasing a freshly cut Christmas tree, wreaths and greenery each year is not a profligate waste of resources, but specifically helps Christmas tree growers and the Ag industry in general. Just think of cut trees as longer-term cabbages specifically planted by tree farmers to be harvested in seven years or so.  After the holidays put discarded trees to good use as habitat for wildlife, or chipped, shredded and turned into compost, thus recycling their nutrients and minerals and enriching the earth. 

On the other hand, choosing a live Christmas tree is becoming increasingly popular. Growing up, it was rare to see a potted or container Christmas tree decorated yet still growing, except for my best friend’s family. Their increasingly crowded backyard had a succession of spruce trees in graduated sizes planted in each previous year.  

Lately, the popularity of live Christmas trees has been on the rise. The problem is that many of these trees don’t survive the holiday season or don’t fit the landscape plan if they do survive. Choose a tree appropriate for the climate, care for it correctly while it is decorated, and afterward, use it to good advantage and site it correctly when planting in the landscape.

When shopping for the tree, consider its mature height and width and plan ahead to decide where it will be planted in the landscape. Savvy gardeners and landscapers dig the hole before they ever go shopping for a tree.

When selecting a tree, choose only healthy stock and not stressed leftovers from last season. Consider good color, good branching structure and flexible limbs. Knock the plant out of the container and look for non-pot bound, non-circling root systems with fresh white feeder roots.  The potting mix should be moist, and there should be no disease or insect damage evident. 

Choose only from varieties that grow well in the area.  While fir, spruce and pine are traditionally used for cut trees, they are not suited for all climate zones. Garden Centers often market a wide variety of cone-shaped trees as holiday options, so choose the one that’s best for the area and the specific landscape, even though it may not be a traditional choice. This is the time to be thinking “outside the box”. What about a broad leaf holly, Christmas Jewel(R) Holly PP14477 (at right) or Teddy Bear(R) Magnolia PP13049 above right? 

Another possibility is a dogwood, redbud, flowering cherry, deciduous magnolia or double file viburnum to decorate? Ornaments would look terrific hanging from bare branches, and one of those might be just the accent plant the landscape needs. What about a cone-shaped rosemary or bay tree? Even a balled & burlapped selection is ok; merely place in a large tub and cover with mulch to keep evenly moist.  

Don’t fail to include the Tropicals section in your search for a living Christmas tree. The Norfolk Island Pine is “nearly traditional,” and one year I didn’t even shop but decorated our oversize Monstera deliciosa with a choice selection of my Mom’s vintage ornaments. It’s the season!

If a hardy tree is selected, don’t bring it inside right away, but keep it outside in a protected area until a few days before Christmas. Keep the soil moist but not wet and sheltered from winds and full sun. Acclimate the tree to warmer temperatures by moving it onto a covered porch or garage over a period of three to four days.
For needle-leaf or broad-leaf evergreens, decrease transpiration from the leaf surfaces and retain valuable moisture within the tree by spraying with an anti-desiccant/anti-wilt product.  A couple of brand names are Wilt Pruf or Cloud Cover.

A living tree that soon will be returned to winter temperatures outside cannot be brought indoors for weeks on end without consequences. Warm rooms with low humidity can cause drying out or dormant buds to break and grow in a “false spring,” only to die when moved back outside. Avoid bringing the tree indoors too early, since the less time spent in hot, dry indoor temperatures the better, and certainly no more than a week. Avoid placing near heat vents, forced air, radiators, stoves, but do consider a window where it will get some sunlight. Keep soil moist.

After Christmas move the tree back outdoors to that protected area so it can readjust for a week or so. When there’s a break in the weather, follow recommended planting procdures, with a wide, shallow planting hole about twice as wide as the root ball, but not deeper.  Plant slightly higher than the surrounding soil because it will soon settle, backfill with the native soil and mulch the tree to retain moisture. Newly planted trees need even moisture, so water throughout winter and spring. The new addition will contribute holiday memories as it adds beauty to the landscape.