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But though an old man, I am but a young gardener.
(Thomas Jefferson)

Come, my beloved, let us go forth into the fields
(Song of Songs)

We have joined forces together since 2003 in a P-Patch in Seattle for the purpose of raising vegetables.  Rebecca comes from a long and distinguished farming tradition, though by former inclination and personal experience was primarily a horticulturist and ornamental gardener.  Michael formerly did his best to avoid getting his hands dirty in the garden, and came late to gardening, but has been gradually coming up to full steam.  

What Is a P-Patch?

The term "P-Patch" refers to an urban communal public site providing small leased plots or gardening allotments for individuals to raise plants, most commonly vegetables.  It is a Seattle-centric term that apparently derives from Picardo Farm, the site of the original Seattle P-Patch. 

Most people when considering vegetable gardening would assume that the garden should be on their own property.  This certainly has significant advantages in terms of convenience, freedom, and security regarding theft of produce.  However, we have come to appreciate that a publicly located P-Patch offers a special atmosphere and advantages not found on private land--these tend to overshadow the disadvantages.  In particular, besides providing shared and communal resources such as tools and compost, it allows a great deal of social interaction with fellow gardeners and casual passersby.  We have enjoyed the numerous opportunities we have had in the past few years to get together down at the "Patch" with fellow gardeners for informal potluck suppers, a nice time to exchange notes on what plants are working well.  There are also volunteer aspects such as contributing to the Food Bank for the needy which add appeal for civic-minded participants.

Purpose of the P-Patch

Store-bought vegetables are getting more and more expensive, and the quality may be unknowable and not always up to snuff.  Organic food raised free of pesticides and herbicides seems increasingly desirable, and Seattle P-Patches require all vegetables to be raised organically.  But the primary benefit of raising vegetables is the deep satisfaction that comes from returning to the basics of tilling the soil, raising crops, and thereby addressing our most primitive needs for sustenance.  One cannot actually sell produce from the P-Patch--that is against the rules--so what "profits" you make must be noncommercial or intangible.  For persons who may have limited travel opportunities, getting to the P-Patch can present a welcome respite from the urban rat race and seem a little like a trip to the country.  The relatively open space of a P-Patch can be esthetically pleasing and calming in a city otherwise increasingly dominated by commercial development.  Although public parks can offer much more athletic activities, the more reflective or older members of the populace can probably benefit from the more tranquil atmosphere of a P-Patch.  

Productivity versus Intangible Benefits

A key question to consider is whether one's P-Patch will primarily serve an intangible therapeutic purpose, so that its produce will be an incidental benefit, or will its produce be its primary or at least a major purpose.  In our case, we have elected to make the P-Patch as productive of crops as possible.  To this end, we have carefully monitored what we plant  and how each plant produces in our specific P-Patch environment.  

Factors for Optimizing Success

Seeds and Vegetable Sets: All seeds come with instructions indicating the optimal time of year to sow (or start indoors), and we also try to pay attention to other specific instructions regarding providing needed nutrients, etc.  If you reuse a seed packet from a previous year, pay attention to how old your seeds are, how long the manufacturer says they can remain viable, and whether they have been properly stored.  If you are using older seeds, plant more than you would from a fresh packet, to compensate for expected reduced germination.

For 2005, we liked the following sources for seeds (many of which are available on the Web): Territorial, Ed Hume, Johnny's, Cook's, Thompson and Morgan, Renees Garden, Seeds of Change, Abundant Life, and Franchi (thru GrowItalia.COM, for Italian items). 

Bed Preparation and Soil Amendments: Initial preparation of the planting beds by hand spading or rototilling, breaking up of underlying clay hardpan, and amending the soil with compost are all desirable for success. When a garden is used year after year and the soil is friable (i.e., it can be readily broken up), the soil requires minimal tilling.  In fact, minimizing tilling may be preferable for preserving the micro-ecological environment of the soil, including the beneficial effects of mycorrhizal fungi.  We do prefer to continue adding compost annually, however, and we are currently (as of 2009) utilizing Cedar Grove Booster Blend (a 50:50 mixture of washed dairy manure and compost).  One should add lime to reduce acidity in Seattle soils.  Weeds must be removed.  We prefer to raise our beds into gentle mounds in order to increase the height of good soil above hardpan, in addition to promoting drainage and improving soil warmth by solar heating.  We use Steve Solomon's recipe for making organic fertilizer containing cottonseed meal, fish meal, lime, and bone meal (from his rather complex and wordy book, Gardening West of the Cascades), but use less of this as a result of the nutrients provided in the Booster Blend.

Trellises: It is also desirable to have good trellises to support tall crops such as pole beans and edible pod peas.  Although we initially tried wood posts, and would ordinarily prefer them for esthetic reasons, we found that these rot out quickly.  (Longer-lasting chemically treated wood cannot be used in a P-Patch in order to avoid soil contamination.)  We subsequently tried using 3/4" galvanized electrical conduit pipe for greater permanence.  However, even these trellises blew over in high winds when they were heavy with pole beans.  Therefore, for 2005 we installed 1 3/8" diameter chain link fence "top rail" as our trellis post and beam material.  These can be fitted together with angle brackets also available at Home Depot.

Biological Diversification and Redundancy: Not all crop items will be equally successful.  Variations in weather and microclimates, inherent suitability of specific crops, seed viability, soil fertility, vulnerability to disease and pests, etc., all contribute to the success of any particular crop item. We have concluded that, where feasible, it is desirable to plant several cultivars (i.e., cultivated varieties) of a particular desired crop, such as beets or lettuce, so that we will have biological diversification and will not be disappointed if a single cultivar proves to be unsuitable.  Of course, the use of multiple cultivars also gives greater culinary interest and variety to the harvests, and makes it possible, to some extent, to spread out or stagger crop harvests over a greater period of time.  It is also desirable to plant more plants than one is likely to be able to eat, thus assuring that there will be produce available for the birds, as well as for one's starving relatives and friends, and the Food Bank. As the saying goes (somewhat pessimistically), "plant one for the rabbit, one for the mouse, one for the crow, and one for the house".  Of course, we also rotate where crops are repeatedly planted for the purpose of reducing outbreaks of pathogens.

Winter Crops: Your garden will be more productive if you include crops that can grow and/or be harvested in the winter.  However, it is less convenient to garden in the winter.  Productive late fall and winter crops include leafy vegetables such as kale, chard, arugula, beet greens, lettuce, and spinach, bok choy, brussels sprouts, broccoli, and leeks.  Currently, we are gardening through the entire year and thus planning for spring, summer, fall, and winter growing seasons.  However, we do not go to the effort of constructing special cloches or other hardcore winter gardening structures to optimize winter yields.  Good information on what to plant and when can be obtained from the very readable Maritime Northwest Garden Guide (by Seattle Tilth).

Theft, Vandalism, and Furry Invaders: Practically speaking, some crops (for example, leafy vegetables such as kale) are less likely to be stolen from a public P-Patch than crops producing big tempting fruits.  In 2006 we experienced our first significant theft (of eight prized winter squashes that we had babied through the hot summer).  One possible countermeasure is to plant unusual varieties of tomatoes and squashes that have a sickly color or bizarre texture and therefore appear unhealthy.  In March 2007, we also sustained lamentable vandalism damage to our carefully constructed trellises, and in 2008 an invasion of incredibly determined rats plagued our formerly tranquil garden, eating up many of our potatoes and beets.  Other gardeners lost sugar snap peas.  These developments have somewhat tempered our enthusiasm about gardening in such a public environment. 

Choosing What to Plant and Assessing Success of Crops

To put the assessment of productivity of crops on a semi-scientific basis, we monitored the success of each crop item for each year up through 2006 in the following manner.

For objective assessment, we weigh the number of units (pounds or ounces) produced for each crop item.  Although stores often sell vegetables by the bunch (e.g., beets) or by the item (e.g., squashes or artichokes), we have converted and standardized our data entry to use only pounds or ounces as the units of measurement.

We also take note of the average or typical market unit market value (dollars per unit) of the organic produce we are raising.  For example, organic snow peas are worth an average of $5 per pound during the season in which we harvest them.  The unit market value is typically measured at the store in dollars per pound or ounce, dollars per bunch, or dollars per other unit.  Since in reality market prices for a crop item fluctuate considerably with the time of year, this value is estimated at the time of our maximum production, or if we have several different crops over multiple seasons of the crop item, we have simply tried to express an average value for the year.  This value has been adjusted where appropriate to reflect the fact that we will trim away some of the stems or other parts of the plant after weighing--trimmings that have already been removed at the grocery. 

The product of unit market value (dollars per unit) and total production (in units) for a year yields the total dollar value for a particular crop item for that year.  

We also keep track of the approximate number of square feet that have been devoted to a particular crop item.  Because of the small size of a P-Patch, every square foot counts. We use a scale map of our P-Patch to assist in planning the distribution of crops for each season, including those which will overlap the same land when considering the entire growing year.  This square footage number is best regarded as just a rough measure of how much space the crop item requires relative to other crop items, since (1) various crops are grown at different times of the year but may overlap partly with other crops, (2) the number of square feet can vary substantially for a given crop item during its growing seasons, and (3) the land occupied is more valuable in the prime spring/summer growing season than in the winter.

To add in the element of subjective assessment or desirability of a crop, we assign a Palatability Index (1 is worst, 5 is best) to each crop item upon harvest and consumption.  This index is based on our personal preferences and how we actually responded to that crop item in the year being evaluated.  Of course, Palatability Index will vary from person to person.  

Finally, we compute a Figure of Merit (FOM) for each crop item, representing the product of the subjective Palatability Index times the total dollar value produced and divided by the square feet occupied by the crop item.  The Figure of Merit is a single number reflecting the relative success or productivity of a crop item compared to other crop items, and includes objective measures plus our subjective preference.

For keeping track of what seeds we plan to order and when to plant them, as well for calculating and maintaining our crop production records that facilitate selecting optimal crops for the following year, we have used an MS Access 97 database, which I utilized to help prepare this summary.

The following table presents the plants we planted in 2005 and therefore a list of potentially useful crops to consider planting in your P-Patch.  They are listed in alphabetical order by name.  In 2005, the significance of FOM is given as follows:

• The highest merit crop items (the top 20% of FOMs) had FOMs of 29 or greater.
• The average merit crop items (the middle 60% of FOMs) had FOMs between 6 and 28.
• The lowest merit crop items (bottom 20% of FOMs) had FOMs of 5 or below.

In the table, the columns are explained as follows:

• Name plus Cultivars: This names the plant or group of plants constituting a crop item as planted this year.  For simplicity, we will often group several cultivars (such as spring/fall lettuces) together. The usual common name is given first, followed by the scientific name and various synonyms in {curly braces}. The cultivars are then shown in 'single quotes', designated as (1), (2), etc. when there are more than one.  In cases where we are not certain that the variety name listed is an official cultivar name, the single quotes have been omitted.  F1 signifies a F1 hybrid--a first generation offspring of two highly inbred strains usually produced by controlled hand-pollination.
• FOM: The Figure of Merit (explained above) calculated for this crop item for this year.
• $/U: The dollar value per unit (ounces or pounds) of the organic crop item in the form in which we harvest and weigh it--i.e., the actual market value (explained above).  
• U/SF: The units (ounces or pounds) we actually harvested per square foot assigned to the crop item for this year.  The units used are the same units as expressed in the $/U for this item.
• P.I.: The subjective Palatability Index we assigned based on our actual experience with this crop item this year (1 = worst, 5 = best).

Crop items with FOM of 5 or less are tending toward the unacceptable, while those with higher FOMs are acceptable.  Put another way, if you plan to grow crops in a Seattle P-Patch, we recommend any of the crops above having a FOM of 6 or greater.  Other crops planted in earlier years that yielded low productivity have included corn and okra, and we have elected not to replant them.

Of course, we have favorites that we will continue to plant even if their FOM proves disappointing (some for instance are visually interesting).  The data in this table represents our actual experience from a single year, and other gardeners very likely had or will have different experiences with various crops items.  

The First Lady's Fine Garden Book

First Lady Michelle Obama has written a new book for 2012, American Grown: The Story of the White House Kitchen Garden and Gardens Across America. She and her team selected portions of this webpage for quotation.  On page 92 she describes the P-Patch program in Seattle, and quotes us extensively (with minor modifications that were acceptable to us).  We are honored to have been included as a small part of this well-written and thoughtful book.  A major theme of it is to promote improvements in the nutrition of Americans, especially poor urban children.  Having access even in the inner city to fresh organic vegetables and fruits plays an important role.  We recommend her book without reservation.  You may click on the link to see a copy of the book page.  (PDF provided by and with permission of the publisher).

Comments and Feedback

Comments and suggestions regarding this web page or the P-Patch experience in general may be sent to MCM at McGoodwin period NET (please convert this this spam-averse address to standard format before using).

Page www.mcgoodwin.net/pages/ppatch.html
Created by Michael McGoodwin
Content Last updated 15 December 2012 (last substantive 15 October 2012)