Tuesday, January 27, 2015

Poor Gardening Weather



It is not very good weather for gardening today. 25 inches at 9 AM this morning and supposed to snow until at least 7 PM tonight.




It is even poorer barbeque weather. That’s my poor Weber kettle being engulfed by drifting snow.




While it is a monochrome world outside, it is warm and toasty inside.





Color will have to be provided by the seed catalogs. The storm is giving me a day off work and the chance to finalize my seed orders. To add some more color to the process, I loaded the pen with Noodler’s Apache Sunset ink for an in-your-face color addition and reminder of summer days. So I’m happy. I have my seed catalogs, a warm fire, and a glass of Cabernet. Just hope power stays on long enough for me to post this. Everyone stay safe.

Sunday, January 4, 2015

Onion Culture



My onion plant order is placed! The only allium I will have to start from seed this year will be the Saffron shallots. I took other bloggers’ advice and ordered my plants directly from Dixondale Farms. Not only is the price cheaper for the two bundles I was planning to order, but it gets cheaper by the bundle, so it’s hard to resist. In addition to Copra and Red Zeppelin, I wound up ordering the Tropea onions I usually grow as well as a mixed bundle of intermediate day onions (Candy, Red Candy, and Super Star). So I will have 200-280 plants showing up mid-April and just have to figure where I will put them.


Dixondale has a lot of growing information and I learned a lot just by watching a couple of their videos. I already knew that up North here I plant long-day onions so that after the solstice when days grow shorter, the onions are triggered to start forming bulbs. But there are some tricks to getting the largest bulbs that’s probably obvious to everyone else, but wasn’t to me.


Supposedly an ideal onion will have about 13 layers or rings (ideal meaning that’s about as much as you can expect to get in a growing season). Each ring in the bulb corresponds to one leaf of the foliage. When daylight triggers bulb formation, the layers start expanding, so the more layers (i.e., the more leaves), the bigger the onion bulb will be. A healthy, rapidly growing onion can grow a new leaf about every two weeks. The plants from Dixondale will have 4-5 leaves and a healthy root structure (versus the 2 leaves that my own transplants have). To get to 13 leaves, it will take another 16-18 weeks after transplant, given ideal conditions. Onions are heavy feeders and require a lot of nitrogen to encourage foliage growth.


So the formula for big onions is:

  • Plant as early as you safely can. The clock is ticking and you want as much foliage as you can grow before bulb formation commences. Once the bulb starts forming there will be no more foliage growth.
  • Buy plants. Ignore the cost, the extra 2-3 leaves they have over homegrown transplants is worth 4-6 weeks of time in your garden.
  • Space onions 4 inches apart in the row, with rows 16 inches apart. Plant onion plants no more than 1 inch deep. The reason for the row spacing is that while onions are shallow rooted, they do develop extensive side roots. In raised beds, they recommend a minimum 4” x 8” spacing. I am going to have to play with the geometry of this for my raised beds. And there is the question of, would I like to have more, smaller onions or fewer but larger?
  • Use a general purpose fertilizer with lots of phosphorus (something like 10-20-10) for good root development when planting. Maybe add bone meal to get the extra P. If you are pushing the limit and planting very early, Dixondale has found that high potassium levels in the soil help protect against freeze damage. In addition to NPK, onions require a lot of micro-nutrients for healthy growth, including magnesium, zinc, boron, copper, iron, manganese and molybdenum, so make sure they are in your fertilizer (or throw in a handful of rock dust).
  • Then starting at two weeks after planting once roots have established, use a nitrogen fertilizer every two weeks. Stop fertilizing when bulb formation starts.
  • When bulb formation starts, make sure the onions have plenty of water. Stop watering when foliage falls over and let the soil dry out before harvesting.
  • Watch for onion pests like thrips and spray if needed.
  • Use a preventative organic  fungicide regularly. Even if fungus disease is not visible, any spores present may increase spoilage and reduce storage time.


The nitrogen fertilizer they recommend is ammonium sulfate, which is a chemical fertilizer and not suited for organic gardens. I will most likely use blood meal. If you have a blood meal rated 13-0-0, you apply a cup per 20 foot of row. I will also be amending the beds with the onions with rock dust and kelp meal to get the micronutrients into the soil.

Saturday, January 3, 2015

RE-Mineralization 1



I recently encountered the new phenomenon (now a fad) of re-mineralization, while looking up some information (see http://growabundant.com/). That led to my purchasing Steve Solomon’s new book, The Intelligent Gardener: Growing Nutrient-Dense Food, which I am in the process of reading. The topic interested me because of my two gardening situations. I currently use raised beds filled with a soilless mix following Mel Bartholomew’s recipe: 1/3 peat moss, 1/3 vermiculite, 1/3 compost. Mel claims a scoop of compost is all you need to garden, but of course he insists that scoop of magical compost has to have all needed nutrients in it. Does it really? If it doesn’t that’s your failing, not his method. I have had mixed results with the soilless mix in my beds. Mechanically, it is great. It thaws early, drains well while retaining moisture, it has a light and fluffy texture that many plants love. But some plants (usually the heavy feeders) have not done well and that makes me wonder why. Are some essential nutrients missing? That is a complicated topic I have been thinking about for awhile and will be the subject of another post.


My beds are also located in a community garden where last year I had the opportunity to share half of an unclaimed plot for a garden. I used it for tomatoes, peppers and summer squash planted in-ground. The community garden was recently reclaimed from sodded fields whose history is vague to me. I doubt the field was ever tilled because of the large amount of ledge showing through in places. Maybe it was pasturage or hay field. At any rate, during the ice age it was under a mile thick layer of ice and the soil is some unknown mixture of silt, sand and gravel deposited by the glacier. So its fertility has always been in doubt in my mind, although fellow gardeners and myself have gotten decent crops from their gardens. I am curious to see how the soil tests out at and what could be done to improve yields for our gardeners using Solomon’s advice.


It all starts with a soil test.The photo above is a picture of a dried sample of the soil from the community garden that has been sent to Logan Labs in Ohio and to the UMass Extension service for testing. When dried, it crumbles easily and looks fairly sandy, but when we get our frequent heavy rains it compacts easily and becomes anaerobic. I have no idea of its actual soil type or composition. The worksheets Solomon uses assumes that the soil test used the Mehlich-3 extractant method, which is the method used by Logan Labs which he recommends. I also sent some of the same sample to the soil lab at UMass Extension, which uses a Modified Morgan method that includes micronutrients and is better suited to Northeast soils. The two tests will undoubtedly produce different numbers for nutrient concentrations and their target values will be different as well, so I am wondering how different the suggestions will be.


I called re-mineralization a fad because a lot of people have simplified it to just tossing a handful of rock dust around the garden. It has gotten so popular that many stores are encountering a large demand for rock dusts (I know, I just bought mine and got the last bag). Solomon's emphasis is much larger, however, trying to balance all the factors that make up the soil (pH, organic matter, minerals) so plants are given maximum opportunity to thrive and produce nutrient dense food. He talks about rebalancing the soil and that is the central theme of his book, not just mineralization. Using soil test results and the worksheets in the book, a prescription for supplements is developed to bring the soil into the right balance of pH, organic matter and ratios of minerals.


First step is to adjust the pH of the soil. The use of lime has been overemphasized in the past, and the recommended use of dolomitic lime can actually cause an excess of magnesium which tightens up the soil. Most vegetables prefer a slightly acidic soil, in the range 6.0 to 7.0. Solomon uses a target pH of 6.4. This target pH will actually be achieved when the four major cations (Ca, Mg, K, Na) are in the proper proportions. If you look again at the soil sample above, I am afraid that the white flecks you see are bits of lime from an over-eager distribution of lime early in the garden’s history. The last soil test in 2011 showed the soil to be alkaline with a pH of 7.6 with a very large Calcium content.


The next step is to address the amount of organic matter in the soil. Besides the usual mechanical improvement of the soil from adding organic matter and encouraging the growth of micro-organisms, the humus increases the ability of the soil to buffer not only cations (positively charged ions) but also anions (negative ions) so they are not leached away by rain and irrigation. There is no point in adding nutrients if the soil cannot retain them. The total ability of the soil to buffer/retain cations is called the Total Cation Exchange Capacity (TCEC) and is the key factor in rebalancing. Light (typically Southern) soils will have 2-4% organic matter and will have a TCEC less than 10. Heavier (typically Northern) soils will have 7-10% organic matter and a TCEC greater than 10. Solomon uses 7% organic matter as the target for northern acidic soils. He points out large additions of compost are not required once the soil reaches the desired level of organic matter and TCEC. The soil in the community garden in 2011 had a TCEC of 51.3 with 10.3% organic matter.


Next is balancing the major cations, Calcium (Ca), Magnesium (Mg), Potassium (K) and Sodium (Na). The target proportions are 68% of the ions buffered by TCEC should be Calcium ions, with 12%  Magnesium ions. Soils having this 68:12 ratio will be loose and friable soils. Higher amounts of Magnesium will cause soils to tighten and clump. Potassium should occupy 4% of TCEC capacity, with Sodium at 2%. If a soil has this 68:12:4:2 cation ratio, its pH should be at the target 6.4. It may take several years to reach target ratios if you have an excess of one mineral, so the prescription may be more involved than just adding supplements. The community garden test from 2011 (Morgan method) had a TCEC of 51.3, of which 98% was saturated with Ca, leaving only 1.5% Mg and 0.6 % K, definitely not a balanced soil.


Next is to balance the anions, the negatively charged ions. Any clay in the soil will only buffer cations. You need sufficient humus in the soil to buffer your anions or they will be easily leached away by rain or irrigation water. The trick is to build up and retain the anions to adequate levels, starting with Phosphorus. Phosphorus is an essential element and low levels of P will reduce plant growth long before symptoms of deficiency evident themselves. The goal for Phosphorus levels is P=K, a level equal to the Potassium content of the soil. Our old 2011 soil test showed a P level of 4 ppm compared to a K level of 108, a very low level of Phosphorus and far from the prescribed balance.


The other key anions are Sulfur, Boron and Nitrogen. Sulfur is an essential element used in building many amino acids. If elemental Sulfur is added to the soil, microorganism will readily convert it to the sulfate anion. In balanced soils, the goal is S= 1/3 P, or one third of Phosphorus levels. Higher levels of Sulfur equal to 1/2 Mg can leach cations from the soil, which can be an advantage if you have an excess of a cation such as Calcium or Magnesium. The sulfates of most cations are water soluble and will then be washed from the soil by rain. For Boron in light soils, Solomon recommends levels about 1 ppm and in heavy soils, 2 ppm. Nitrogen is heavily used by plants and easily leached from the soil so its amount varies so widely that the standard soil test does not test for it. Usually it is added when planting and as needed during crop growth and is not a permanent fixture of soil fertility.


So my soil tests for the community garden have been sent off and it will be a week or two before I get results. Then I will use the worksheets to calculate recommended supplements. The problem I have, which is probably beyond my capabilities, is dealing with the excess Ca and high pH of the soil. The Ca saturation percentage on the 2011 soil test was 98%, leaving little room for the other cations. Adding Sulfur would seem like a possible solution for both the Ca excess and the pH, but the soil already has a very high S content, equal to 2x Mg. I have no clue why that is. Hopefully, the new soil test will be more encouraging and these anomalies will disappear, maybe just the result of a bad sample in 2011.

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