1. Editors Corner
   • The Seeds You’ve Sown
   • Dr Tomato Gives You the Dirt
2. News & Events
   • Newmarket Farmers Market
   • Low Tunnels are Here!
   • The Dr Tomato 2010 World Tour Dates:
   • Spring is Here
3. Questions from Readers
   • “Leaching” of greenhouse plastic into the soil?

Editors Corner

The Seeds You’ve Sown

Smelling the fragrance of the apple mint I’m currently cutting reminds me of my grandfather’s stone wall garden when I was a child.  When I was five years old, I asked my grandfather where food comes from. So, he tilled up his backyard and had us grandkids plant a veggie garden. Being that he loved science and charting information, we did various experiments and monitored our results daily. I recall waking up in the mornings thinking about my plants and desperately wanting to get right outside to see if they had miraculously produced fruit over night!

Tonight, as I was doing a midnight check on one of our small greenhouses which has an experimental passive heat retention system Dave and I designed (the greenhouse actively grows plants 12 month out of the year with absolutely NO electricity, oil, or wood stove heat, just the passive power of the sun), the following struck me:
When we planted the garden in my grandfather’s backyard, I noticed he started many of the plants in his sun room and wanted to know why. He explained how plants prefer to stay warm when they are getting started…so I had the idea to cut the bottom off of two liter soda bottles and place them over my plants in the garden, trying to replicate smaller versions of his sun room. I was intrigued to see the difference in the first few weeks in the development of the plants that were under the bottles verses the ones that were left uncovered. This was my first experiment in fuel free heat retention!

There’s no way he could have known at the time how his in-depth, summer-long response to my simple question would generate a life-long reaction of trying to perfect the answer to my original question “Where does our food come from?”

Papa the Great, if only you knew the seeds you had sown, and how well they’ve grown! Thank you.  James, 3/14

Dr Tomato Gives You the Dirt

In the last newsletter, I spent quite a bit of time discussing an important, and often overlooked, component of healthy soil – pH. I will ask you to recall some of that discussion as I proceed with this article. If you ask any organic grower what THE most important element in successful gardening is he/she will tell you – the health and quality of the soil!

If I asked you right now to tell me what soil is and why it is so important, what would you say? It is needed to grow plants? If so, what about hydroponic growing?  Could you tell me what it is composed of? What makes it “healthy” as opposed to unhealthy? How the different components relate to each other and work together? How to change its texture or structure? In this newsletter, I will attempt to give you a brief (OK you know me by now, but BRIEF is a relative term!) overview of soil, its composition, texture, structure, requirements and “needs”. As I have stated at the beginning of all my articles, I will use broad generalities and suggest that you continue looking into this very complex topic on your own.

First, let’s take a look at what makes up soil. What’s in this stuff that we lovingly plant our seeds and seedlings in? In fact, let’s do a science project and attempt to make a “perfect” batch of soil.

On average, about 50% of the stuff we call “soil” is ground up mineral particles of varying sizes. If we think about this single fact for a minute, we will gain a lot of understanding about soil. On one end of the soil TEXTURE scale is sand – quite large particles, large air spaces in between the particles. This end of the soil texture scale is called LIGHT (not referring to the weight). On the other end of the soil texture scale is ultra fine particles that have virtually no spaces in between them. This end of the scale is classified as HEAVY. So what do these differences mean to us as growers. Consider the SAND (the ultimate LIGHT soil). Because the particles are so big and the air spaces so large, sand will hold virtually no water! And, because of the size of the inter-particular spaces, any nutrients that may temporarily attach themselves to the particle surfaces are quickly flushed out by rain. On the other end of the scale is the HEAVY soil. The particles are so close to each other that there is virtually NO ability to drain. The soils on this end of the scale are CLAY and SILT. You are all familiar with the drainage problems with “heavy” clay.

So, as growers, it is obvious from a TEXTURE standpoint that we want something in between these two extremes. That “something” is LOAM. Loam is the soil TEXTURE that we strive for – LIGHT enough to give proper drainage characteristics and HEAVY enough to retain water (AND therefore nutrients) for proper, consistent plant hydration and nourishment. If you are at all familiar with “dirty talking”, you also know that loam itself is classified as Heavy Loam, Light Loam or, the loam we strive for – Medium Loam. OK, when we talk soil TEXTURE now, we know that we are trying to get a BALANCE between the sand characteristics and the clay characteristics. Hold water and nutrients with the fine clay sized particles and allow drainage through the sand sized particles.

If ground up mineral particles of varying sizes make up about 50% of the stuff we call SOIL, what is the other 50%? You may be surprised but most of the remaining 50% of a volume of soil is AIR and WATER. Where is all that air and water? It is in those air spaces we just talked about. And the best BALANCE of air and water retention/drainage is found in that TEXTURE mix of soil we now know as LOAM. But we all know that we can’t just take a bucket of sand and some clay sized mineral particles, mix the two together, plant our tomatoes and reap a huge harvest. There must be “something else” again.

This time, that magic “something else” is ORGANIC MATTER. Believe it or not, some very “Healthy” soils only contain about 5% organic matter. What is this organic matter? The compost you work in, the leaves that fall on the soil and decay, grass clippings, the manure from your neighbor’s horses or cattle, peat moss, chicken manure, straw mulch etc. This organic matter provides both NUTRIENTS for the plants and is critical in HOLDING water for proper hydration. Organic mater acts as a sponge in the soil to hold water in those air spaces. What are you commonly told to add to your soil to hold more water? Peat moss, right?

Well, that’s pretty much it for understanding what “good” soil is from a TEXTURE standpoint. A balance of fine and coarse mineral particles to reach that LOAM status, a balance of drainage and water retention, a lot of air spaces and somewhere around 5-10% organic matter.

But wait, there must be more to it than that! This would make for a pretty slim PhD program in soil science! OK, there is more to it.

Perhaps the best way to move forward from here is to think about the word BALANCE a little more. Remember the last newsletter? The article on pH. Perhaps the most important thing I asked you to remember is that – just because a nutrient (like calcium) is in the mineral particles of the soil doesn’t mean it is AVAILABLE to be used by the plant! Why not? Remember, if the pH is not in BALANCE with the pH requirements of the particular plant, the calcium will be “locked up” and not available OR it may be released in too great a quantity and be toxic to the plant.

This whole issue of BALANCE extends to ALL of the individual components that make up our “perfect” soil. Let’s go on a field trip to the local organic farm that has been practicing proper soil management for years. We walk out into the middle of one of the planting fields with our shovel in hand. Dig a clean hole about a foot and a half deep. Put the shovel down and then lie down and look at the sidewall of the hole. You will probably first notice the rich, “earthy” smell of the soil. The color is dark brown to black. The soil is moist but not wet. There appears to be a very rich top layer about 8-10” deep (this is called the top soil). The soil is “airy” and not compact. Then you look closer and notice some other things. Earth worms, millipedes, bits of organic matter, little beetles, and if you could look with a microscope – bacteria and fungi. ALL these elements work together and must be BALANCED to create a “Healthy” soil.

The TEXTURE we talked about in the first part of this article provides the framework or matrix for the soil. The air and water in the matrix spaces are critical for roots to be able to take up nutrients, move deeper into the soil and carry on chemical reactions needed for growth. The organic matter is the “buffet” of micronutrients needed to produce those wonderful, sweet, juicy tomatoes we all strive to coax from our plants.

For truly successful growth, we need the TEXTURE elements above to be present. BUT, we also need a component called STRUCTURE to optimize our growing. If you let a soil with good TEXTURE components set for a while, you will start to see the proper STRUCTURE develop.

Think of a house being built. The framework is up, the outside is sheathed, the roof is on, and there are more piles of wood and materials scattered around the inside. The texture elements are all there. But over the next number of weeks, the TEXTURE elements are rearranged, moved, nailed up, wired, plumbed – and a smoothly functioning home emerges. The TEXTURE elements take on an efficient STRUCTURE – and a family can effectively and productively “grow” and flourish. In the soil, this same concept takes place. The TEXTURE elements are “worked” and the soil begins to become BALANCED for the plants that will call it home. How does the STRUCTURE develop? The process of the soil freezing and thawing works the soil and creates passages, pores and aggregate “clumps” of different sizes. Roots growing into the soil also form channels and passages – breaking up compacted areas. This process of breaking up the soil, forming passages and creating groups of aggregate “clumps” makes the soil – FRIABLE. Water, oxygen, nitrogen and carbon dioxide can move through the soil to and from the roots. Earthworms are “nature’s rototillers”. They aerate the soil, bring organic material from the surface (like the mulch around your plants) deep into the soil, deposit their rich manure (called casings) to fertilize the soil and support other smaller life forms in the soil. All these STRUCTURAL elements contribute to maximize the amount of nutrients in the soil and the ability of these nutrients and water to effectively reach and be utilized by the plants. As these processes “work” naturally over time, they tend to become BALANCED. The pH that we spent so much time on in the last newsletter is the critical “unseen” element that works in harmony with all the texture and structure elements. But nature will generally work to stabilize the pH in a reasonably good range if all the texture elements are present and the structure is allowed to develop. Read the last newsletter if you haven’t done so yet.

I can hear you now “I’m happy for the organic farmer that he/she has such good soil, but I don’t even know if my soil can sustain life!” Don’t despair, let’s take a look at how you can begin to understand what you have for soil NOW and how to turn it into “healthy” soil. First, do some tests. Have your soil tested for pH and nutrient levels. But remember, lab tests are imprecise when taken out of the context of your soil Texture and Structure. Go out into your garden and do these tests yourself, 2 or 3 days after a rain. First, the squeeze test. Pick up some of your soil and rub it between your thumb and forefinger. You will be able to “feel” the levels of sand or clay sized particles. Gritty particles are sand and the slippery particles are clay. Remember, you are looking for a mix of the two. Second, the squeeze and release test. Pick up a hand full of soil, squeeze it quite hard and then release it. If it crumbles after you release it, that is good because it indicates a “loam” structure. If it holds its shape as a ball, that is indicating more of a clay type soil. If you can roll that ball into a “sausage” and it holds that shape, this indicates very high clay levels. Third, do the “Perc” test. Dig a hole 6” across and a foot deep. Fill it with water and let it drain. As soon as it has drained completely, fill it again and begin to time it. If it takes longer than 8 hours to drain completely, it indicates a very high level of clay or a drainage problem that needs to be addressed. Fourth, dig a hole, get down on your knees or stomach and LOOK at the soil! You now know what to look for.

It is probable that you will find that your soil is not quite that “perfect” soil out in the organic gardener’s field. Here are some of the reasons your soil might not be BALANCED or “healthy”. Do you live in a recently built house? Remember, most builders will strip away the loam and precious topsoil, build the house, refill the area with sand and then cover the sand with an inch or two of “loam”. When you try to plant something, you dig through an inch of soil and then try to plant in sand. Do you walk on or drive machinery over the soil you want to plant in? When you do either of these things, you COMPACT your soil and destroy that precious STRUCTURE we just talked about. Your soil may just be too sandy or have too much clay naturally to begin with. Have you or someone else gardened in the soil for a long time and not practiced good soil management techniques? Your soil may have become severely depleted of nutrients. Or, have you used chemical fertilizers and insecticides for years and killed most of the beneficial organisms in your soil?

If your soil has excessive clay or has a serious drainage problem, you will have to amend it with a more granular sand mix OR just seriously consider raised beds with new soil. Raised beds are also the fastest and best fix for that 1” thick layer of loam over sand in new construction areas. Compacted soil? You will have to rototill or hand turn the soil and start your good soil management techniques from that point on. Want the number one, all time favorite, time tested, prime directive for improving your soil? ADD ORGANIC MATTER!!! How much? Well, remember that organic matter should make up around 5-10% of the soil matrix. This translates to adding a 1”thick layer of compost, humus, aged manure etc to the top of the soil EACH year. Then gently hand turn it in. If it is a bulkier material like mulch straw or leaves you may have to make the layer around 4” thick due to the lower nutrient content. This addition will be close to the 5% organic matter number mentioned many times in this article. Of course, your soil might need more organic matter added if it is in really depleted condition.

Getting your soil to that “perfect” level using organic techniques will not happen in a week or for that matter in one season. It will take several years. So, in the meantime, you can use organic fertilizers to augment the soil’s nutrition as your soil fertility builds naturally.

As you build your soil over the coming years, remember: DO NOT DISTURB YOUR SOIL WITH TOO MUCH ROTOTILLING OR HAND DIGGING! Remember that soil STRUCTURE that is so critical in healthy soil. Work your soil minimally! Do not walk on or drive over the soil you plant in. We all tend to “over work” our soil.

Think of your soil as your garden’s bank account. Whenever you plant something – a vegetable or flower – and harvest it, YOU TAKE SOMETHING OUT OF THE ACCOUNT.  Just like money, you can’t do this for too long before your account runs dry – either of money or fertility.

One of my favorite books, and one I highly recommend to all of you – SELF SUFFICIENT LIFE AND HOW TO LIVE IT –by John Seymour describes it like this. Always practice the LAW OF RETURN. Whenever you take anything OUT of your soil, put something BACK! As you harvest (make a withdrawal), make sure you BALANCE that with a DEPOSIT of organic mater. You and your soil with thank you and reward you with a bounty!

WORK WITH NATURE – NOT AGAINST IT!

Until Next Time,

The Healthy Home Harvest team
feedback@healthyhomeharvest.com

Become a fan on Facebook:

News & Events

Newmarket Farmers Market

When: Saturday, March 20th from 9:00am until 1:00pm.

Where: The Stone Church, Newmarket NH.

Healthy Home Harvest, LLC  will be at the Newmarket Farmers’ Market tomorrow at the Stone Church from 9 to 1. We’ll have our famous Shiitake and Oyster Mushrooms, fresh herbs, mature lettuce pots…also will be debuting our new Low Tunnel Garden Covers and yes…ROWDY ROOTS organic potting mix!!!!

The venue is small and intimate. The vendors are diverse, enthusiastic and friendly. There is great food available and some very talented live musicians provide first class entertainment. The feeling is more like a family gathering than a trip to the local store. We look forward to seeing you at the next Newmarket Farmers Market!

For those of you not familiar with Newmarket, the Stone Church is up on the hill behind the Post Office in downtown Newmarket. This is our favorite farmers market! Good atmosphere, live music, some wonderful vendors, good food and a variety of  products. See you there!

Low Tunnels are Here!

We now have low tunnel hoops available in both the 4 foot wide and 6 foot wide sizes! With a simple and very low cost low tunnel you can start planting – can you say –NOW! Lettuce, spinach and several other spring veggies can be planted in them. You can buy the hoops alone or we also have kits that give you an “instant” raised bed WITH low tunnel hoops attached! And you won’t believe the prices! For those of you going to the Newmarket Farmers’ Market this Saturday, we will have hoops there.

The Dr. Tomato 2010  World Tour Dates:

Dr. Tomato will be giving a number of presentations in the coming weeks. On April 21st, he will be at the Barrington Library at 6:30pm with the Barrington Bloomers. Tomatoes are high on the list of discussion but as always, all questions are welcome. This get together is open to the public. On April 10th and April 24th he will be at Blue Seal in Rochester from 9:00am until 1:00pm. Any and all subjects will be the topic. Come learn how to use low tunnels, an inexpensive and highly effective way to extend your growing season. On April 17th he will be at the Blue Seal in Windham, Maine.

Spring is Here!

It is official, Dr. Tomato reports that he has crocuses blooming at Castle Anam Cara! And, he is going to be planting spring crops in his low tunnels this weekend. Ahhhh….

Questions from Readers

Question:

I have constructed a small, plastic hoop house over two of my raised beds. It is working out very well. A lot of condensation can form on the inside of the plastic and then drip into the soil below or directly on the plants. Should I be concerned about any harmful “leaching” of the plastic into this condensation and ultimately consumed by me?

Answer:

On the surface, most people would answer this question by simply saying “No problem”. However, I will just give you a little more in depth answer. In the past (and indeed today in some applications) the plastics being used to manufacture almost everything were in the PVC (polyvinyl chloride) classification. These plastics were a melting pot of highly toxic chemicals including things like phthalates, dioxins, mercury, lead and so on. These chemicals were not bound together very tightly so leeching into the environment (i.e. –you) was the norm. Also, look at the current controversy over the compound Bisphenol-A in drinking bottles and food cans. To resolve some of these serious problems, new plastic formulations have been developed. Amongst the most widely used new formulations are the plastics classified as polyethylene plastics. These plastics come in a variety of different chemical configurations including High Density Polyethylene and Low Density Polyethylene. Many of the drink containers that used to be made of PVC configurations are now made out of HDPE or LDPE. Look at the bottom of your milk container or gallon water jug from the store. Most will have the recycling triangle and a number 2 or 4 or 5 or a stamp that says HDPE or LDPE and then the number. These plastics are considered “safe” and not leeching chemicals. Is the leeching zero? Probably not. But most research shows the levels to be of little or no consequence (only YOU can evaluate what that means to you).

So, back to greenhouse plastics. Most greenhouse plastics are now made out of HDPE or LDPE plastics that would also be classified as “safe” (usually LDPE #4). Indeed old greenhouse coverings can now be recycled. When you get condensation on the inside of the plastic and it drips onto the soil is there any chemical that leeches out – probably, but it seems in almost undetectable amounts. Also, the amount of chemicals falling onto your veggies from acid rain containing a variety of compounds is probably of far more concern. Most high quality greenhouse plastics actually have an anti condensation coating on the inside to prevent condensation from forming into droplets and falling onto the plants below.

Your question is a good and interesting one. At this point in time, most research indicates that you don’t need to worry about any negative effects from condensate droplets. You could look into how you might better ventilate your tunnel during the day. Please feel free to contact me if you want any further information on this. Again, good question! I won’t even ask you to ponder the question of wrapping your food in plastic cling wrap before you put it into the refrigerator!

Happy growing,
David “Dr. Tomato” O’Connor

About the Newsletter

The Healthy Home Harvest newsletter is a bi-weekly publication which consists of news, events, how-to and reader submitted questions.

If you have any questions or feedback, please email us at feedback@healthyhomeharvest.com