Tag Archives: soil health

Urban Sanctuary

Urban Sanctuary

By Cecelia Lillard, Florida Master Gardener Volunteer and James Alton Thomas, Greenville Township Senior Master Gardener Volunteer

This article appeared in the August 2019 Issue of Gardening in Orange County. Click here to subscribe!

This article profiles an urban lot that was transformed into an oasis for body, mind and soul as well as for wildlife.  This lot belongs to a local Master Gardener and illustrates how much privacy, beauty and biodiversity can be created with thoughtful design and considered plant choices.  We’ll review the design principles employed in this yard and then take a look at the ecological needs fulfilled through the design and its implementation.

A bright green garden - houses in the background and bright lush green garden in the foregroundFirst and foremost, this design provides privacy and the sense that the space is an outdoor room.  The lot is 50′ wide and faces southeast.  The edges of the property are bordered by deciduous and evergreen trees.  The tall Norway Spruce provides a strong anchor for the southern border and creates a shade garden for almost half of the yard, while the mature deciduous trees provide both frame and boundary for the property.  Given that this garden is in shade much of the time, plant textures are emphasized in throughout the space.  Since the plants are in groups instead of individual plants, the various textures become harmonious and interesting rather than chaotic to the eye.  The repetition of plants by massing gives the design a simplicity that helps quiet the mind and gives one an opportunity to linger in areas and simply enjoy the beauty of a plant’s texture and color.

A beautifully green garden with trees in the background and a small grassy area with a large planter in the foreground
The central planter provides the main focal point of the yard and is the only place where we find a traditional lawn.  The repetition of red in the plants helps to unify the yard and gives the focal point additional structure.  The use of evergreen boxwoods around the base of the container ensures that the focal point will be held even in winter when the planter is moved indoors and allowed to go dormant.

The lawn around the focal point draws the eye to the back of the circle where a stone path peeks between the low shrubs and groundcovers.  The curving shape of the path gives the landscape a sense of movement and entices one into the farther spaces.  The copper birdbath provides another focal point that draws the viewer’s eye and invites the viewer to another part of the garden that is more private.  The red pole, which supports an unseen, yet occupied birdhouse, gives us a hint that there is more to that part of the garden than we can see and provides a touch of mystery.

A lush green gardenThe yard evokes a feeling of balance with the shrubs softening the borders of the property and the understory trees filling the gaps between the shrub layer and the canopy of the deciduous trees.  The varying heights of the plants provide visual interest and contribute to the feeling of privacy that is created in such a small space.  The repetition of color throughout the garden contributes to the sense of balance, with the yellow-greens contrasting with the darker greens, yet not competing with them.

Seasonal interest was also a major consideration in the design of this space.  There is year-round interest provided by many elements of the garden.  The plants were chosen not only for their texture, but for their bloom times and flower colors as well.  There is a continuous supply of flowers in the garden throughout the spring and summer and into fall.  The changing color of the leaves of the trees and shrubs during the autumn supplies the visual interest that flowers provided the rest of the season.  In the winter, the evergreens take center stage, furnishing a stark contrast to the more delicate structures of the deciduous plants.

Overall this garden creation has a feeling of unity, where all of the parts work together to create a coherent whole.  The massing provides a rhythm that is relaxing and the multiple textures provide interest within that rhythm.  The reiteration of certain colors also unifies the space by visually connecting different areas of the property.

green stripped caterpillar with a red head on a leaf stem
Rosy Maple Moth Caterpillar  (Dryocampa rubicunda)

Looking at the yard from an ecological point of view, the property provides all the layers of a forest garden:  tall tree layer, low tree layer, shrub layer, herbaceous layer, ground cover layer and, of course, the root layer.   The tall tree layer consists of both deciduous and evergreen trees.  These trees provide food in the form of seeds and shelter within their branches to birds and squirrels.  The leaves of the deciduous trees also supply an important habitat for insects, including butterflies and moths, providing spaces to lay eggs and food for growing larvae.

A back beetle with orange stripes and long antenna on the white florets of a Queen Anne's Lace flower
A longhorn beetle on the umbelliferous flower of Queen Anne’s Lace

Since the garden was designed to be in continuous bloom for more than half the year, it can be considered an insectary.  There are various flower shapes throughout the garden, providing food for many different types of insects.  Some insects prefer umbelliferous flowers, while others prefer flowers with central florets like asters.  The diversity of flower shapes and bloom times helps ensure that beneficial insects will have a continuous food supply and will help keep invasive and/or problem insects at manageable populations.

As we have spent much of this issue discussing soil and the soil food web, we need to look at our garden through that lens.  In addition to providing mulch and habitat for overwintering insects, fallen leaves contribute to the soil structure and organic matter content in the soil.  These photos were taken in spring and we can see how full and lush the vegetation is early in the season.  This verdure is due not only to the care of the gardener, but more so to the health of the soil where these plants are growing.  The soil food web is very dynamic in an environment like this and the result is the beauty that we see in these photos.  May you be inspired to use these design principles and nourish your ecosystem to build a beautiful garden of your own.Drawing of a carm with icons highliting different management practices, soil health benifits, and soil organisms that are important to soil health. Click on the picture to learn more.

For links to resources that will help you design your own urban sanctuary, check out Cornell University’s “Site Assessment for Better Gardens and Landscapes“.

Click here to learn more about Backyard Conservation.

Charcoal as a Soil Amendment

This article first appeared in The Times-Herald Record on Saturday, May 11, 2019 in the Home & Garden section.

By Joe Gregoire, Orange County Master Gardener, Cornell Cooperative Extension Orange County

I’ve heard that adding carbon to the soil by mixing in charcoal is good for plants.  Is this correct?  Jessica from Monroe

burning wood in a fireplaceGreat question, Jessica.  And as I’ve just recently cleaned out my fireplace from the winter and wondered if I could use the ash in my garden, I’ve done a little research on the topic that I’ll share with you here.

There is a long history to the practice of adding ash and charcoal to soil and is a proven method of soil improvement.  The pre-Columbian Amazonian peoples developed an understanding of the importance of soil carbon as they worked to meet their agricultural needs in their hot and humid rain forest environment.  Their warm, wet climate created conditions in which soil organisms quickly decomposed organic material – that was then absorbed into the rapidly growing rainforest flora.  When rainforests are cleared and plowed, this soil is quickly depleted of soil carbon and susceptible to erosion, making food production difficult to sustain on the same land for more than a few years.  However, archeologists have found that ancient Amazonian cropland contains large deposits of dark, rich soil called Terra Preta that was made by these ancient farmers between 2,500 to 4,000 years ago.  This Terra Preta contains high amounts of charcoal created through the process of pyrolysis (burning organic material in high heat and low oxygen) which preserves up to 50% of the carbon vs. converting it into CO2 gas through complete combustion.  Pyrolysis produces a very porous and stable form of organic matter through physically and chemically altering the composition of the biomass being burned.

pile of charcoal bitsUniversity studies have shown that adding charcoal (also called Biochar) to soil increases the soil’s water-holding capacity, reduces soil density, improves soil structure, and has been proven to reduce soil nutrient leaching and increase crop growth. Pre-packaged biochar can be purchased from retailers today or can be made at home by buying or building a biochar kiln for home use.  Many low-cost designs can be found online and enable the conversion of biomass (wood) into charcoal to amend the soil.  Biochar can be produced from a variety of materials – trimmings from woodland and yard maintenance, agricultural waste like corn stalks, and purpose grown biomass such as bamboo. The pH and composition of the biochar that is produced is directly linked to the material used to produce the biochar, so if making your own, be sure to avoid contaminants such as treated or painted lumber.

Biochar has many properties that have potential to enhance soil fertility and is a highly stable form of organic matter, as the 4,000 year-old Terra Preta demonstrates.  Organic matter in soil is important for retaining moisture and building soil structure through aggregation, which also provides pore space for drainage.  Soil organisms depend on this balance of air and water in soil to survive and thrive. With increased soil life comes increased soil nutrients to feed your plants.

If you have access to fireplace ash, this can be another ready source of charcoal and other beneficial soil amendments.  Wood ash is a good source of potassium, lime, and micronutrients (which are taken up from the deep roots of hardwood trees used for firewood, such as oak and maple).  It is best to add ash to the compost pile rather than directly to the garden, as the high concentration of lime can alter soil pH and may burn sensitive plants.  The alkaline nature of wood ash can also have a neutralizing effect on compost, as the decomposing materials in a compost pile can become somewhat acidic.  Do not use ash from a charcoal grill, as this ash may contain chemical residue from lighter fluid.

Because of the alkaline nature of wood ash, avoid using it around acid-loving plants such as azaleas, rhododendrons, and blueberries.  Wood ash can also be used as a natural repellent for pests such as snails and slugs who will resist crossing a line of wood ash laid around their favorite plants (the salts in wood ash are an irritant to these soft-bodied pests).  The wood ash needs to be reapplied after a rain or watering to remain effective.

Carbon in the soil is the key to soil life.  Growing plants exude carbon into the soil through their roots in the form of sugars produced through photosynthesis.  These exudates attract and feed beneficial bacterial, fungi and other microorganisms that live and die in the area surrounding plant roots, providing plants with nutrients they need to be healthy.  Our addition of carbon to the soil, in the form of charcoal, can provide additional material for this symbiotic relationship to play out in our garden soil.  And in doing so, we can play an important role in removing carbon from the air and returning it to the soil through our everyday love of gardening.

Click on the graphic below to learn more about soil health!

How can you improve your soil health? A link to an interactive infographic that explores soil management practices, soil helath benifits and soil organsim functions. (Sustainable Agriculture Research & Education - SARE).
An Interactive Exploration of Soil Health and How to Improve It

To learn more about the benefits of biochar and current research on biochar visit:

Biochar – Cornell University

Biochar and Compost Facilities – Cornell University

Terra Preta de Indio – Cornell University

To learn more about using wood ash as a soil amendment check out:

Best Management Practices for Wood Ash as Agricultural Soil Amendment – University of Georgia

Guide to Using Wood Ash as an Agricultural Soil Amendment – University of New Hampshire

Wood ashes can benefit gardens and lawns – Oregon State University