Planting Soil Blocks

April may be my busiest time of year, and I am very late in my posting this month. One of those busy things is transplanting dozens of seed flats full of young plants. It’s now time for many of them to go outside.

My experience with Soil Blocks has been really great. I get very good results and avoid using pots whenever possible, but nothing ever goes as planned. This year I’ve noticed two problems. The first was I used a different brand of worm castings in a few trays. These plants struggled and it looked to me like there was a phosphorus deficiency and I found it necessary to supplement them with some liquid fertilizer to keep them going. The other problem I noticed was that for some of my plants I believe I started them a little too early in the season and by the time they were transplanted some of the lower leaves started to yellow, also indicative of a nutrient deficiency.

traysPictured here are many of my Brassica transplants: three varieties of kale, two broccoli types and a purple cauliflower. These seven trays had been growing in my basement for at least four weeks prior. A week before my transplant date I moved the young plants outside into the hoop house so that they can begin to feel what the outside world is like. This is called hardening-off.

The next step is to prepare the transplanting bed. I first used a hula-hoe or scuffle-hoe to quickly mop up any weeds that had germinated and pull any larger weeds. I then added some humic acid, kelp meal and some rock dust made of crushed basalt. Mix this into the top two or three inches, then rake the bed out flat.

Now I determine spacing, information usually given on the seed packet. I’ve learned that not all seed packet information is the same. I usually also look through a reference book or two and search the internet as well. Your experiences and individual soil conditions will also suggest differences. I do most of this look up during the winter months when I am stuck indoors and document them on my calender.

bedrowFor transplanting, the first step is to determine the plant spacing. Plant spacing is easy, it’s the distance recommended between each plant. Don’t confuse that with seed spacing, you want the final spacing between plants after thinning. I review, but usually ignore the row spacing. Row spacing is how many feet between growing rows if you’re farming, or as many gardeners do scaled-down farming. Pre-industrial gardening is a nearly forgotten art. Most gardeners base their knowledge on the experience of farming and scale that downwards into the garden space. The spacing used for farming is very inefficient and was born out of the need to accommodate a tractor.

For my Brassica’s, I started at the end of the four foot wide bed and measured out two rows for the broccoli and cauliflower, and three rows for the Kale. Please note that the distance between my rows is the plant spacing, NOT the row spacing. You can even go a little smaller if you stagger the transplants in each row. Another thing I’ve learned is to be sure and think about how your going to weed later in the season and to always leave enough room for your favorite weeding tool. I normally space my bed rows no less than 6-8 inches apart. Then I take a stick and carefully draw the rows down the length of the bed to mark them.

Now I extend the measuring tape down the length of the bed and fix it there. Using a hand hoe I quickly dig transplanting holes using the measuring tape to guide the spacing. When you have more than one row in the bed, I alternate the transplant holes. For example, with my kale I used 12 inch spacing and I dug holes down the first row on the foot markers (1, 2, 3, …). The second row I offset the holes by 6 inches (1.5, 2.5, 3.5, …), and for the third row I went back to the foot markers (1, 2, 3, …). This actually put each plant at about 13.5 inches apart. This gives you whats called BED SPACING. In the same space using traditional rows I would have only achieved two rows, not three, and I just increased my yield by 33%.

sbOnce all the holes are created, I decided to insert a small handful of high quality worm castings into each hole and mix it up by hand a little. Then I carefully lowered each block into its new home, but haven’t buried them just yet.

Since this blog is about Biological Gardening, how could I leave that out. I now mix in some beneficial bacteria with several gallons of water and use a watering can to wet each block well. After this I carefully bury each plant up to its cotyledons. The cotyledons were those first two seed leaves that formed after germination.

Since I did this work a few weeks ago now, I can also report how they are doing: The plants with the bad worm castings, have recovered and are now growing well, although they are still behind the others. The plants that were started a little too early are still alive and growing but they did struggle to get through a few light frost. The plants that were started indoors at the appropriate time, are doing amazingly well and are bright, green and happy. Despite the differences, of the 224 brassica plants featured here I haven’t lost a single one.

Why would the plants I started only one or two weeks earlier be struggling from a few light frosts when the others are so nice? Their brix was low because the block didn’t have enough nutrition to support that extra growth time. We can discuss this more in the fall, but a high brix plant is not phased by a little frost, as the extra sugar/nutrition lowers the freezing point of the plant.

Cheers,

~Sean

50 Years of Lost Nutrition

I keep talking about food quality but haven’t yet mentioned what that might actually mean, let’s start that discussion now. There are a number of qualitative factors that can be applied to food, but one that’s familiar to most people is the nutritional value. Fruits and vegetables are good sources of many important vitamins and minerals, aren’t they?

min-vitIn a 2004 study (1) of common garden vegetables there was found to be a significantly reliable decline from 1950 to 1999 according to USDA data. It’s actually quite easy to look up the information yourself, and I did just that for three vegetables: broccoli, carrots and corn. The chart to the right shows the numbers from 1950 (2) and the latest information from 2001 and 2008 (3). I added an extra column showing the percent difference.

Broccoli is frequently touted as a high calcium food but as you can see here it contains 2/3 less calcium than it did only 50 years earlier. To get the same nutrition as your grandparents you would need to consume up to three times more! Nearly all of the vitamins and minerals for these foods has declined, and there’s nothing unusual about these three either, as the data shows similar declines for every vegetable, fruit and grain.

USDA data only goes to 1950, but the British have information that goes back to 1936, and a similar 50 year study from the United Kingdom (4) demonstrated the exact same thing, consistent dilution of nutritive value of all foods.

There were significant reductions in the levels of Ca, Mg, Cu and Na, in vegetables and Mg, Fe, Cu and K in fruits. The greatest change was the reduction of copper levels in vegetables to less than one-fifth of the old level.

ukcarrotsIf any cause for this decline is ever given, I believe it to be poorly conceived. In the Davis study the author boldly says “any real declines are generally most easily explained by changes in cultivated varieties.” I am not questioning that plant genetics can make an impact, but that soil quality makes a far greater one. This fact is occasionally mentioned but never discussed in detail.

There are also a number of documents showing how differing soil across the US can significantly change food nutrition. The study Variation in Mineral Composition of Vegetables (5) illustrates this quite clearly. Tomatoes grown in Indiana contained 250% more calcium (15 mg) than those grown in Georgia ( 6 mg). Today the USDA says tomatoes contain 10 mg of calcium.

A huge variation also exists between two otherwise identically looking products. In the same study the best tomato had 23 mg of calcium, while the worst had only 4.5. Spinach is even more amusing as it’s known for being high in iron. I found this website that ranked spinach at #8 in the top 10 sources for iron, and the number given isn’t even accurate, it’s 1/3 higher than the USDA says it is. In the study the best spinach contained 1,584 ppm of iron, while the worst had but 1.

cationsexchangeableinsoilPlease don’t think that I’m saying 50 years ago food quality was high, it was better for sure, but was it great? Unfortunately, it was already well known long before 1950 that the nutritional value of our food had been in decline, already beyond the point of giving good human and animal health. The most glaring example comes from the 1936 US Senate Document 264, an article written about the problem:

The alarming fact is that foods —  fruits and vegetables and grains — now being raised on million acres of land that no longer contains enough of certain needed minerals, are starving us, no matter how much of them we eat.

And what about your own garden? I was shocked when I realized just how poor much of my garden produce was, but I also had a few successes and that encouraged me. As a gardener you are in the best possible position, for you have an opportunity to take charge of your food, your environment and your health by growing exceptionally nutritious food.

~Sean

1 Changes in USDA Food Composition Data for 43 Garden Crops 1950 to 1999. Journal of the american College of Nutrition, Vol. 23, No. 6, 669-683 (2004)
2.Composition of foods: raw, processed, prepared USDA Agriculture handbooks, 1950, http://naldc.nal.usda.gov/naldcPUB/search.xhtml
3. USDA National Nutrient Database, USDA National Agricultural Library search engine, http://ndb.nal.usda.gov/ndb/search/list
4. Historical changes in the mineral content of fruits and vegetables, Anne-Marie Mayer, British Food Journal 99/6, 1997, 207-211.
5. Variation in Mineral Composition of Vegetables Firmane E. Bear, Stephen J Toth, and Arthur L Pice, Soil Science Society of America Proceedings 1948, Volume 13. pp. 380-4, The Soil Science Society of America, Madison, Wisconsin, 1949