Thursday, January 22, 2015

Eating on the Wild Side: Selecting the Most Nutritious Varieties of Fruits & Vegetables

Stephanie Rukowicz

Just in time for seed ordering season, some food for thought. Which varieties of fruits and vegetables offer the most nutrition? Last month, I attended the Selecting Seeds for Healthy Vegetables workshop at the Penn State Extension office. It featured discussion of Jo Robinson’s Eating on the Wild Side: The Missing Link to Optimum Health and an investigation into which seed vendors offer specific nutrient dense varieties. The majority of attendees were urban farmers looking to select the best varieties to grow and offer to their communities.
As a broad summary of the text, Robinson discusses how, historically, cultivated plants have been bred for maximum flavor, appearance, storage and durability, with little thought given to nutritional content. Over the past several thousand years, nutrition has been bred out of our food. Only recently have scientists started investigating bioavailability of phytonutrients (like antioxidants), sugars, and proteins.

Workshop attendees spent time researching which specific varieties noted by Robinson are currently offered in 2015 seed catalogs. High Mowing Organic Seeds included the greatest overall number of varieties listed by Robinson (see below for a catalog excerpt of High Mowing's beet varieties).
The four circled beet varieties are said to be highest in phytonutrient content
(except from page 8 of High Mowing Organic Seeds 2015 Catalog).
Robinson generalizes that the closer a variety looks or tastes to its relative found in the wild, the more nutritious it should be. Often this means that a more nutritious variety is more colorful in appearance (think purple potatoes over white) and possibly less sweet or more bitter (think Granny Smith over Golden Delicious). She recognizes that there are exceptions to the rule, noting the example of white-fleshed peaches having twice the nutrients than yellow-fleshed. The choices are not always intuitive, so she recommends shopping with a list to select the most nutritious varieties.

A short list of varieties for seed selection can be found on her site (, with a more in-depth list found in her book.

Not ordering seeds this year? Robinson also offers tips on how to select varieties for maximum nutrition when shopping at the grocery store as well. A PDF of Robinson’s Shopping Guide for optimum health can be found on her site (

To learn more about the book and the author's research, listen in on an interview she did in 2013 with NPR's Science Friday (

Thursday, January 8, 2015

Your Lovely Tree is Dying from the Inside Out

Kimberly Labno

I consult with urban dwellers on their horticultural needs. Recently, I met a client with two gorgeous mature white oaks flanking the entrance of his Center City residence. One of the trees had a fungal growth at the base, about 12 inches in breadth and maybe 1.5 inches in height, and it had been routinely removed for appearance sake by the owner's house staff. The tree had an overall strong canopy. Even though the wound was shallow and there was little wood rot in the trunk, I knew the tree was dying.
                                                               (courtesy of RHS)
The tree fungus is Ganoderma sp., commonly known as shelf or bracket fungi. The fungus causes what is called butt rot and root rot. It has significant impact on oaks, and potentially especially those near the end of their life expectancy of 65-85 years old - note this expectancy is based on trees in naturalized settings, not urban tree pits. The visible fungus is a fruiting body, which means that the fungus is systemic.

If it helps, you can visualize a flowering shrub with infected roots and flowers in bloom- the fungus has established in the base and/or roots of the tree and the visible fungus is the flower in bloom. There is no cure and removing the fruiting body has little to no impact on control of spread, outside of reducing the number of spores released that may enhance disease spread from say tens of millions to just millions in number. The plant is dying from the roots outward. Eventually, the tree will show signs of sickness like leaf dieback and discoloration. Based on the literature, the lifespan of a tree with this fungus is something on average like between several and ~ 10 years. In natural settings, most trees with this rot meet their end from breakage or toppling in winds/storms.

The client was a sad about losing the trees and although the tree was leafing out well and he could play a waiting game for the infected tree to die- and infect the neighboring oak, he choose to seek removal estimates from professional arborists. The arborist concurred with my diagnosis and outlook and recommended replacement trees that are probably familiar to many as reliable street trees.

To learn more, here are a handful of references.

Thursday, January 1, 2015

Constructing a Small Rain Garden

Constructing a Small Rain Garden
By Pat Vance
The Philadelphia Water Department (PWD) has made a strong commitment to controlling erosion and excess run-off in the city, including some imaginative and innovative large-scale projects. I found an inexpensive, simple PWD project I could do in my own yard with just a shovel!

The house I moved into a few years ago had a half-sized basketball court in the backyard. I briefly considered removing it until I calculated the expense and work involved. Then I decided to
make the best of it. However, after a couple of heavy rains, I realized I would have to do something about the rain water run-off.
I consulted a web site from the PWD with guidelines for building a rain garden. 
Here is the url:
A rain garden is a swale or depression surrounded by a berm, positioned where rain run-off can be temporarily held until it can infiltrate into the ground.  Rain from impervious surfaces such as roofs, parking lots, or the occasional basketball court can be diverted into the garden rather than causing erosion or ending up in the storm sewer. The water is held only temporarily. A rain garden is not a pond or water feature. The water will drain into the ground over a fairly short time.
There is a link on the PWD site for a PDF with guidelines for building a garden. It lists some guidelines for the selection of a good site:
1. The garden should be at least 10 feet from building foundations. This guideline is the most important to follow, even if it means that rain garden may fall short in some of the other considerations.
2. Position the garden to accommodate most, if not all of the water draining from the surface. In my case, if I built my garden along the entire edge of the court, I would place it too close to the foundation of my house. So I restricted the size accordingly.
3. The garden should be at least 20% of the surface area of the drainage area. The area of the space I had available was just slightly over 20%, but even if I had not been able to build a garden quite so large, I figured that whatever I did would be helpful.
4. Drainage should be adequate to allow infiltration of rain water collected. The PWD web site also includes a simple way to test this. Here's the URL:
Remove the top and bottom of a coffee can and then push or hammer the can a couple of inches into the ground. Measure the side of the can above the ground and fill the can with water. Start a timer and one inch per hour, the site is adequate.
calculate the time it takes for the water to drain from the can. Repeat this test a few times to assure accuracy. If the drainage rate is at least
Now some guidelines for shaping the garden.
1. The depth of the swale should be 6-8 inches.
2. The height of the berm should be at least 4-6 inches.
3. The height of the berm above grade, should be no more than one-third the width of the berm. My berm was 3 or 4 inches high, so I made sure it was at least a foot wide.
To construct the garden, I placed a row of stakes along the court, and another row on the opposite side of the garden. I ran string between the rows of stakes and adjusted it to be level with the court. Then I measured the stakes at the outside of the garden for the height of the berm
A note of caution: Be sure it is safe to dig! Contact Pennsylvania One Call system by dialing 811 to be sure you are not disrupting utility lines! Hitting one would be extremely dangerous!
As I dug out the swale, I used a ruler to measure down from the string. As I removed the dirt from the swale, I placed it on the berms.
When I had the garden shaped correctly, I used a hose at full force to watch where the water flowed
from all angles of the court.
The final consideration: Which plants to use? All the usual considerations for planting a garden apply with one notable addition: the soil will be very wet at times, so be sure to choose plants that can tolerate that. The PWD pamphlet has a list of some possible native plants, but I decided to go with what I had available.
A friend was splitting a large patch of Japanese Iris, a plant that can tolerate high moisture. Another friend was splitting Athyrium or Lady Fern and I used those as well.

And the results? A resounding success! This inexpensive, simple project has drastically reduced the run-off from the court, and I have a garden that's lovely to look at.