Top 10 Tips when Gardening with Children

1. Serene adults with their own enjoyment of the garden provide roles models for the child to imitate. Remember, gardening is caught, not taught!

2. Plan ahead to maximize success. Site the garden in full sun near a water source, and enrich the soil with compost.

3. Easy Does It. Try a small garden plot for starters, 2 x 4 feet or 3 x 3 feet.

4. Quick results are best for short attention spans. For example, try radishes instead of asparagus.

5. Little children tire easily. Let the adults provide the support for the child and do the weeding, but let the kids pick the cukes.

6. The small size of the child calls for appropriately scaled, child - sized tools, providing teaching opportunities for pride of ownership and proper care of tools. Be aware of good quality.

7. Individual adult attention, one-on-one, is a reinforcer in and of itself.

8. External recognition such as a blue ribbon in the Children’s Class of a juried Flower Show, a small cash prize at the Youth Division of the County Fair, or simply a printed certificate at the neighborhood Show & Tell, will be replaced later by pride and self satisfaction.

9. Use the child’s harvest, for example, after the strawberry plants start yielding, take a strawberry shortcake to school for a class treat, or pick some flowers to take to a shut in.

10. Claim your own rewards: renewal of a child-like joy and sense of wonder

 
 
 
 
 
 
 
 
 
Ferry Morse seed packets for children.

Summertime Heat Tolerance

Plant Hardiness and Heat Tolerance

It’s summertime and the livin’ is easy; fish are jumpin’ and although the cotton is not yet high, the weeks of 90-degree temperatures are upon us. This got me to thinking about how plants get heat-stressed and the entire concept of heat-tolerance ratings. However, since the gardening public is more familiar with the idea of cold hardiness, I’m going to start with that.

Cold Hardiness
Plant hardiness is a complex phenomenon and depends on many variable qualities of individual plants (not of their projected sites). The Royal Horticulture Society (RHS) Shorter Dictionary of Gardening points out some natural adaptations to cold temperatures include deciduous or herbaceous habit, procumbent growth, thicker bark, seed dormancy or accelerated life cycle, among others.

Cold hardiness is a characteristic attributed to plants that are capable of withstanding the rigors of winter without greenhouse protection. Often abbreviated as “hardiness”, the general population sometimes uses the term loosely to mean a general toughness or ability to survive, but that’s not strictly the case. The actual story is really interesting!

Hardiness Zones

Back in 1960 the U.S. Department of Agriculture (USDA), in cooperation with the American Horticulture Society (AHS), produced an ingenious map based on annual minimum temperatures. Isotherms, contour lines connecting points of equal temperature on a map, were developed using data from 124,500 weather stations and analyzed by the Meteorological Evaluation Services, Inc., in Amityville, NY and labeled Hardiness Zones. Brilliant! They extrapolated variable characteristics of hardy plants to Zones on a map, thus producing an approximation; a guide or rule of thumb; shorthand, as it were, to enable people to get an idea of where plants will make it through the winter.

I am too young (!) to remember a time before Hardiness Zones were in common usage in the horticultural world, but this was a real breakthrough. This precious map was widely publicized, often printed on the inside covers of gardening reference books and was/is used extensively. In 1990 the map was revised to include Canada, Mexico, and Hawaii, and later zone maps were also produced by others for Europe, South Africa, Australia, New Zealand, Japan and China. But keep in mind, theses zones are simply an approximate indication of the coldest temperature band in which the plant will survive. Thus, most gardeners are familiar with the concept of plant hardiness.

Heat Tolerance
However, cold isn't the only factor determining whether plants will survive in the garden. At 86 degrees F. (30 degrees C.) plants begin to experience physiological damage, and with the advent of weeks of 90 degree Farenheit temperatures in Atlanta I really wanted to look at the concept of heat tolerance in plants.

As part of the 75th anniversary celebration of the AHS (1997), a Heat-Zone Map was published, based on the number of days each year that the daily high temperatures reach or exceed 86 degrees. The data used to create the map was gathered and again analyzed by the Meteorological Evaluation Services, Inc. This map has 12 zones which overlap but unfortunately do not follow the hardiness zones exactly, so when using both maps to make selections, two zones are indicated for plant. Each of the 12 zones of the Heat Tolerance Map indicate the average number of days each year that a given region experiences "heat days"-- temperatures over 86 degrees (30 degrees Celsius)-- at the point when plants begin to decline due to the heat. The zones range from Zone 1 (less than one heat day) to Zone 12 (more than 210 heat days). The use of Hardy or Half-Hardy Tropicals (what we used to think of as “houseplants”) in the garden provides an entire category of plants that laugh at heat waves, and it seems to me that this trend became popular after the advent of the Heat Tolerance data.

Plants vary in their ability to withstand heat, not only from species to species but even among individual plants of the same species! Unusual seasons-fewer or more hot days than normal-will invariably affect results in the garden. And even more than with the hardiness zones, gardeners find that many plants will survive outside their designated heat zone because of complications by many factors such as microclimates, rainfall, hot winds or cloud cover.

On the AHS website, H. Marc Cathey, AHS President Emeritus, points out, “The effects of heat damage are more subtle than those of extreme cold, which will kill a plant instantly. Heat damage can first appear in many different parts of the plant: Flower buds may wither, leaves may droop or become more attractive to insects, chlorophyll may disappear so that leaves appear white or brown, or roots may cease growing. Plant death from heat is slow and lingering. The plant may survive in a stunted or chlorotic state for several years. When desiccation reaches a high enough level, the enzymes that control growth are deactivated and the plant dies.”

So the AHS Plant Heat-Zone Map is used the same way that the Hardiness Map is used, but unlike the Hardiness Zone Map, this map is highly proprietary. “The AHS Heat-Zone map is a copyrighted document that is wholly owned by the American Horticultural Society. Any reference to, reproduction of, or attempt to code plants using the map's information without written consent by AHS is a violation of the copyright. Durable full-color posters of the AHS Heat-Zone Map are available for $9.95 each. To order check the website http://www.ahs.org/publications/heat_zone_map.htm or call (800) 777-7931 ext. 119.”

I think because the Heat Tolerance Map is not open source, this resource is less widely used, which I think is shortsighted; too bad. What do you think? Do you bother with the heat tolerance zones when choosing plants for your gardens?

Photo credits: Thermometer-Ohio State Engineering, Hardiness Zone Map-Missouri Extension, Tropical containers-author photo.

Top 10 Tips for Watering the Garden & Landscape

Watering the Garden
Since plants are 90 – 95% water they can quickly wilt if they get too dry. Good gardeners monitor the water available to their plants (rain) and avoid this stressful wilting with extra irrigation. Some plants (thinking Hydrangeas here) wilt every day on hot afternoons but come back by evening. Others (Rosemary) are less tolerant and quickly turn yellow when water stressed.

But too much water isn’t good either. Plants require a balance of both water and oxygen around their roots. Overwatering excludes the necessary oxygen from the soil causing roots to rot and die and resulting in yellow or wilted tops. On the other hand, too little water does not allow the roots to replace water lost by the plant through transpiration from its leaf surfaces. In this case, tender roots shrivel and die, and again we get wilting. In both cases, either too much or too little water, the plant suffers from lack of moisture in its tissues.

I have long been uncomfortably amused by the dark concept of “PWP”. The Permanent Wilting Point is a technical term for “bye, bye baby”, the point of no return when the plant is DEAD.

So I’ve assembled my Top 10 Tips for Watering the Garden and Landscape Plantings.

1. How often to water depends on how often it rains. As a rule of thumb, most plants thrive with about an inch of water a week. Visualize a short, 10-minute downpour every two or three days. Keeping the soil lightly moist prevents it from drying out completely. It’s the fluctuation that is damaging to most plants.

2. How often to water also depends on the soil type. Clay soils hold water a long time, while sandy soils are like a sieve, letting the water quickly drain away below the root zone. Both types of soil can be improved with the addition of organic matter. Organic matter adds lightness and air to clay soils; it acts as “tiny sponges” holding the water in sandy soils.

3. The very best time to water is in the cool of the morning, when the wind is calmed, evaporative water loss is minimal and the rising sun quickly dries off the leaves.

4. Water the soil, not the leaves. When water sits on plant foliage for hours (e.g. overnight), fungus spores can germinate and attack leaves, buds, flowers, and fruit. Plants susceptible to leaf spots, fruit rots, and flower blights are best watered in the morning, when the warming sun will quickly evaporates the water and discourage fungus development. Avoid watering disease-susceptible plants in the evening.

5. Wind and air movement increase water loss from the pores (stomata) on the leaf surfaces, called transpiration. That’s why fuzzy or felted plants like lavender or silvery artemesia do well in hot, stressed situations. Anti-desiccant sprays are available for houseplants or for broad leaf evergreens when the soil freezes up north, but I don’t have much experience with them. Consider microclimates when planting.

6. Plants need more water on hot, bright days when the relative humidity is low, and evaporation is high. An insulating layer of organic mulch is good at reducing the evaporation.

7. Water needs vary with the type and maturity of the plant. Some vegetables and bulbs are tolerant of low soil moisture.

8. Set a rain gauge or two in an open area of the garden to learn how much water the garden receives each week and judge the need for supplemental irrigation accordingly. Use a straight-sided can or purchase a calibrated, easy to read gauge at a garden center.

9. Stand-alone containers or hanging baskets tend to dry out more quickly due to the combination of crowded, intensive planting and increased surface area along the sides of a porous pot, so they depend on careful monitoring. The smaller the container, the more frequently it needs water.

10. Sometimes a wilting plant does NOT need more water. This is true if plants are growing fast and the leaves get ahead of the roots' ability to provide them with water, and is easily corrected. Unfortunately it is also true if the roots are rotted from TOO MUCH water, which brings us back to the PWP.

Notably, young plants and new transplants require more moisture more often at the soil surface to help their root systems take hold. Water lightly but more frequently to accommodate their growth needs. Mature plantings with large root systems are best watered heavily but much less frequently than younger plants. The moisture soaks deep into the soil and encourages the roots to thrive. Follow watering guidelines in your municipality and happy gardening!

Tiny and Tough, Micron® Holly Really Measures Up

Have you heard the old mouse’s tale: “if prickly hollies are brought into the house, the husband is in command, but if smooth-leafed hollies are used to decorate, the wife rules the home”? I'll have to try it. Holly leaves and bark were used for various ailments by native Americans. Some wore sprigs of holly during child birth to ease pain and assure delivery of a healthy baby. Several southeastern tribes brewed a purgative, emetic drink from the leaves of native yaupon holly (memorialized by it species name, Ilex vomitoria) in the spring, which allegedly restored lost appetites, preserved good health and bestowed courage in battle.

Micron® Dwarf Yaupon Holly is super-adaptable to all types of growing conditions. A choice dwarf selection of native holly by Garden Debut®, Micron® is extremely durable and flourishes in a tremendously wide range of conditions, from sun to shade and from wet to dry soils! Much more compact than the typical evergreen dwarf yaupon, Micron® Holly has a characteristic mounding or pillowing habit that makes this shrub distinctive in the landscape. Slow growing so it never needs pruning, Micron® reaches a mature height of only 20 – 30 inches and a wider spread of three feet. Resilient plants are profusely branched and low mounds of rich green foliage add a distinctive rich color to the garden in winter (Zones 7 and warmer).

Micron® Holly is an exceptionally versatile garden performer because it is not particular to the type of soil provided, and while it is tolerant of wet soils it is also more drought resistant than other hollies. Wild yaupon grows along the Gulf and Atlantic coastal plains of the southeastern United States with a range extending from the northern coast of Virginia south to central Florida and west to southern Oklahoma and eastern Texas. This makes Micron® Holly an ideal landscape plant in warmer U. S. gardens for a multitude of uses, including small hedges, garden borders, edging, foundation plantings and massed on slopes to control erosion and to simply look good. Prized for its slow rate of growth and resulting dense wood, pruning or shearing is never necessary with Micron® Holly. Additionally, Micron® is deer resistant and yields a slight fragrance when the tiny flowers bloom in late spring. If you live in the Southeast, look for Micron® at independent garden centers near you.

Top 10 Reasons for Organic Mulch!

Wow! I love organic mulches. Here are the Top 10 Ways Mulch can Benefit Landscape Plants:

1. Moderates soil temperatures like an insulating blanket

2. Moderates soil moisture levels by limiting evaporation of moisture already in the ground

3. Unifies the landscape design by providing pleasing color and texture throughout

4. Reduces erosion and splash-back on residences by softening the impact of raindrops on bare earth

5. Suppresses weed growth by preventing weed seeds from sprouting

6. Enriches the soil by adding nutrients when decomposing, improves the physical properties of the soil and can worked into the beds at the end of the season

7. Encourages the proliferation of earthworms, which aerate the soil

8. Provides a zone of protection from string trimmers for tender trunks

9. Cushions the impact of foot traffic

10. Hides irrigation and power lines, valve boxes, outdoor lights and landscaping hardware

How to Mulch:

A blanket of mulch of about 2 – 4 inches and not much more is best. If the trunks of trees or shrubs come into contact with mulch, ideal conditions for the growth of fungus disease can be present. Reduce this possibility by leaving a 3 – 4 inch space between the mulch and the trunks, or an 8 inch space around mature trees.

I can only think of 2 Reasons Not to Mulch:

1. Ornamental poppy seeds, foxgloves, nigella, and other annuals, perennials and natives like purple cone flower need bare ground to sprout and won't sprout under mulch. So pull back the mulch in an area where you intend to scatter seeds.

2. Pine voles (nasty, stub-tailed, mice-like herbivores) tunnel on top of the soil but under too-thick mulch to gnaw on the crowns of my favorite and rarest plants, especially during the cold months. Still, I think the benefits outweigh any drawbacks.

Let me know your favorite kinds of organic mulch.

Parterre Garden: Embroidering with Plants

While working on my talk on ‘Herbs of Shakespeare’ presented last week, I got re-intrigued with the elaborate evergreen gardens they planted back in those days.

Formal, ornamental gardens of the French Baroque period and English Renaissance were typically laid out on level surfaces adjacent to the grand buildings or halls, par "on", terre "the ground". They were typically bilaterally symmetrical and often foursquare, divided by broad, level paths of gravel, sand, turf or swept earth. A stone or brick curb was often used to outline the design, and within, the planting beds were edged with tightly clipped evergreen hedges, often of boxwood, for four seasons of beauty.

Within the planting beds the woody ornamentals were tightly planted in clipped hedges inscribing decoratively geometric designs. The sensuous shapes of boxwood scrolls and arabesques placed within the very formal, straight lines of the garden’s basic design lent an elaborate gracefulness. The geometry could also be more angular and consist of straight lines and 90 degree angles. A Flower Parterre had a riot of colorful flowers changing with the seasons planted within the compartments of the hedges. Or the clipped parterres need not have any flowers at all. A Plain Parterre had nothing but the basic outline of the clipped evergreen hedges of the planting.

Broad pathways were part of the design, and allowed the garden to be admired by people strolling through it. However the true beauty of the parterre was best viewed from the upper windows of the mansion. This bird’s eye view displayed the design like a pattern of crewel embroidery.

Although today’s gardeners are not about to plant a formal parterre, low evergreen hedges are still useful to contain flowers or define an edge. Consider trying Green Borders Boxwood, new this year from Garden Debut®, for low, informal hedging and when dark green color is needed to provide structure and interest in the landscape.

This littleleaf boxwood displays a sturdy growth habit and dense, dark green foliage. Slow growing, Green Borders reaches a mature height of 2 – 3 feet tall and a slightly wider spread of 3 – 4 feet, making it excellent for informal garden edging and borders. Plants are profusely branched and the glossy, dark green foliage adds a distinctive rich color to the garden in winter.

Not just another green box, Green Borders Boxwood is exceptional because it is tolerant of moist soils. Other notable characteristics include deer resistance and a slight fragrance when the tiny flowers bloom in late spring. Green Borders Boxwood flourishes in conditions of sun to dappled shade. In full sun, shallow-rooted plants appreciate a little mulch to keep soils cool.

Boxwoods have been used for centuries by gardeners for small hedges, garden borders, edging, foundation plantings and as accent plants, prized for their slow rate of growth. Although pruning or shearing is never necessary with Green Borders Boxwood, littleleaf plants may be sheared into tight the geometric shapes or the formal topiary of yesteryear if desired.

Gardening Thoughts on Mother's Day

There is something to be said for celebrating Mother’s Day in the most beautiful month of the year, amidst all the spring flowers. Wikipedia has a remarkable chart listing the timing of Mother’s Day in many countries around the world, and I noticed the majority of them do fall in May. 

My darling Mother showered me with unconditional love and her many talents included watercolor, design, dressmaking and cooking, but I attribute my love of gardening to my Gardening Grandmother. Cozily seated on the sofa with the snow piled up outside Grandmother would let me choose dozens of vegetable and flower seeds from the glossy catalogs to order for the garden. When springtime rolled around, we would plant an organic garden, turning under cover crops and organic mulch, lining out seeds of leaf lettuce, hilling up the cukes, ladling out manure tea. 

Grandmother had a garden that puzzled me, with old fashioned flowers and new hybrid vegetables all thriving together under fruit trees. It was much later that I learned hers was a “cottage garden”. The branches of her plum trees were so weighted down with fruit that 2 x 4s were needed to prop them up and prevent them from breaking. I NEVER remember being asked to weed, but inhabited a privileged sphere and was allowed to pick tiny cucumbers at 3-inches, rub off their prickles and munch them up in the garden still warm from the sun, or to pop the sensitive seed pods of Balsam or Touch Me Nots at will. 

In June, we would go to the annual Community Rose Show just before closing on the last day, and Grandmother would gather up the discarded roses to take home. These were carefully rooted under quart Mason jars, and in later years people would stop their cars to get out and marvel at the display of roses planted the length of the driveway.  She had green fingers and I absorbed the best gardening practices unconsciously.  

I still have a great treasure: Grandmother’s favorite trowel and I use it only occasionally. I have her seed box and I still grow descendents of the balsam and feverfew that used to grow in her garden. I’m a mom and when my sons were small we gardened together too.  One has turned out to love gardening, but the jury’s still out on the other one. I have high hopes of hitting two for two.