Master Gardener Class - Mar. 25 (Intro and Soils)
The first Master Gardener class was last night at UM-Helena College of Technology. After an introduction to the concept of the Master Gardener program, they taught us the first part of the soils section (soil is the stuff plants grow in; dirt is the stuff under your fingernails or on your floor).
I am going to summarize what each class covers here on this blog, for those who are interested and also for my own self-study. The class meets once a week for 8 weeks.
All those gardening books are great and helpful, but they pale in comparison to the local knowledge of a longtime gardener.
Guest Speaker: Dennis Flynn of Valley Farms (Helena Valley)
We had a guest speaker kick off the class, Dennis Flynn from Valley Farms, who has been growing primarily ornamentals and tomatoes here since 1974. This is a summary of what he told us.
The safest time to plant (transplants and direct seeding outside) in the Helena area is around Memorial Day (last of May, first of June). We are in a mountain valley after all. Our last freeze is usually in April but can go well into May, and the soil has to dry out and warm up some. Basil and peppers stay in containers until Father's Day, put in a wagon you move in and out of a protected area until then. Tomatoes work this way better too. Don't buy transplants and such from the big box stores. They aren't very well suited to local conditions. Go to a local nursery.
80% of people's problems growing here is in soil preparation. Helena's alkaline soils don't do well with adding peat moss. There is a product called Glacier Gold which is recommended. It is made in-state by a company that chips up mostly lodgepole pine slash piles, which makes this product very acidic (5.9). This helps balance the pH of our alkaline soils (we range 7.2-7.6 in local soils). 6.6 is the Holy Grail for soils pH balance. There is more on pH below.
Glacier Gold also has some of the streptomyces bacteria which is beneficial for adding soil life to our situation, which is very deficit in this regard as well. But don't try and grow stuff by adding alkaline soils under a pine (or other conifer) as this will harm both the pine and whatever you are trying to grow there.
Another common problem in our area is using too much fertilizer such as "plant food" or Miracle-Gro. Use these if you have to only on annuals, not perennials, and NOT on anything you want to produce fruit (such as tomatoes). These products are salts, and our Helena soils are too salty as they are. "Plant-food" is a marketing term, and a misnomer anyways, because you can't "feed" plants. Plants manufacture their own food through photosynthesis.
Proper composting is the key for most plants, including vegetables, not intensive fertilizers (except for particular species of flowers). Daniels organic fertilizer was recommended.
If you treat a plant too well, such as a tomato, with all kinds of commercial fertilizers, they won't fruit. You will get a huge plant but no fruit. Fruit are the plant's "babies" that the plant produces to ensure the survival of its kind, after it dies. If you pamper the plant, it thinks, hey, I'm gonna live forever. What do I need kids for?
We have trouble producing tomatoes sometimes in Helena. We get tomatoes to the green stage, then they sometimes die before ripening (of course part of the ripening problem is our very short growing season). If the tomato is green, but with a sucked-in black bottom, the plant was drawing its water from the fruit (fruit "babies" also serve as water reservoirs for the plant under stress, like a camel's hump). Part of the problem in this case is iron deficiency and too much salts (fertilizers make it worse). If you have a green tomato with small black spots, the problem is calcium deficiency.
Last year we had an early storm that killed a lot of the leaves still on the trees. Those leaves stayed on the trees all winter. (Leaves are not really green, that is just active photosynthesis- the real color of leaves can only be seen when photosynthesis stops- maple leaves are really red, and ash leaves are really yellow). But don't force those leaves off, let them leaf out naturally. The quick freeze didn't give the tree the normal time for the abscission layer to harden and force off the leaf in the natural cycle of things. If the leaf is forced off too early in the mistaken belief this helps the tree get new leaves, you are actually damaging the tree and it may not recover.
Never prune a birch or maple until much later in the summer here. This coming weekend (tomorrow) it is supposed to get into the 70s, and it is time to give all the evergreens a good watering. For successful gardening, you really need to understand the local conditions, and that means talking to local nurseries that have been operating for a while, and to older local gardeners who have all that experience.
That summarizes Mr. Flynn's portion, though he had a lot more to say, and he is a very successful local grower.
What is the Master Gardener program?
The Master Gardener program was started in the state of Washington in 1972, and has spread nationwide. It is generally administered by university extension offices in the various states, in response to increasing needs for gardening information. The Master Gardener program's goal is to create a resource bank of volunteers for local communities to assist in this effort. There are three levels of becoming a Master Gardener (I, II, III); I have just started the first one (Master Gardener I). At the end of each course, we are tested.
And then Master Gardeners of the various levels are required to serve as volunteers for the community based on the level attained (MG I = 20 hours, MG = 30 hours, MG III = 40 hours). There are various ways to do your volunteer hours, including giving talks, helping schools, helping at farmer's markets, creating community or demonstration gardens, writing articles, and helping with the Extension phone lines.
Soils I
The next section of the class was on soils, which was divided into two parts. Only part 1 was covered this first class.
Soil is a diverse combination of weathered rock fragments and minerals, with decaying remains of plants and animals (organic matter). You need to know your on-site soil profile (cross section of the soil strata (layers)). The appearance, color, and thickness of each is different from place to place.
The very top, the ground surface, is called the O horizon, and it is made of humus, the decaying layer of organic materials (insect husks, leaves, sticks, etc.)
Under that is the A Horizon, the topsoil, the richest darkest layer of soil, which is a zone of leaching soluble salts.
Below that is the B Horizon, the subsoil, which is the zone of accumulation of salts.
Beneath that is the C Horizon, the parent material. The portion nearest the top is the weathered parent material broken up by erosion, chemical action, etc. This goes through gradations (gradational contact area) to the fresh parent material below, the bedrock.
An ideal soil is half solid material and half pore space (the tiny gaps around the material). The solid material is mostly mineral (45%) with a little organic material (5%). The pore space is half water (50%) and half air (50%).
The 5% of organic material is further subdivided into humus (not hummus!) 80%, roots (10%), and organisms (10%). Humus (HYOU-muss) is organic material made up of decomposed plants, animals, and micro-organisms. Hummus (HUM-us) is an edible paste made up of garbanzo beans/chickpeas :-)
That 10% which is organisms includes bacteria, fungi, actinomycetes (which are microorganisms which resemble bacteria and fungi but are neither), and protozoa. There are 70 pounds or more of these little guys in every 1000 square feet of a lawn's root zone (about 10 feet by 100 feet, or 20 feet by 50 feet).
Soil Texture
The mineral portion (45%) of soil is made up of particles which are classified based on particle size as sand, silt, and clay. This is known as soil texture.
Sand (~2.0 mm) is easily seen as particles by the naked eye and is rough when moist and run between your fingers. There are different kinds of sand. Much of ours here in Helena is quartzite based, but on the beach in Hawai'i it is generally coral-based (except the black beaches which are of decomposed volcanic rock). Sand is excellent for drainage and aeration, but poor at holding water.
Silt (~0.05 mm) has a smooth consistency like flour when it is dry, but is hard to see as particles with the naked eye. The powdery stuff that made the Iowa Loess Hills is silt (loess is wind-blown silt). Silt is good all around, for drainage, water-holding, and aeration.
Clay (~0.002) cannot be seen as individual particles with the naked eye. It is hard when dry and sticky when wet. Clay is poor for drainage and aeration, but excellent at holding water.
The test to see if it was clay or silt when I was in archaeology is to grab a little moist bit between forefinger and thumb, and then pinchpush against it outward like toothpaste- if it made a little ribbon, it was more clay and if it crumbled before it got beyond the fingertip it was more silt.
The soil texture diagram (triangle) shows the sweet spots for combining the three textures, as sandy loam and silt loam, for growing garden plants. But be aware that you can't just add sand if you have too much clay. It doesn't work that way. You get clayish globs in amongst the sand. You need to add compost and slowly work that soil closer to where it needs to be, or go for raised beds etc., if your soils have way too much clay or sand.
To check your soils texture, just take a big jar and fill it 1/3 with a representative sample of your soil, and then top it off with water. Then add a drop or two of laundry detergent and shake. Let it settle for a day. The clay, silt and sand with resolve into different bands of texture (clay on top and sand on the bottom). You can then estimate your own soil's proportions by percentage, and compare it to the chart.
The effect texture has on soil is how it holds or drains the water/air mixture (field capacity). Plants need a happy medium- too much saturation, they drown, and too little, they wilt.
Structure of the particles is another characteristic that affects texture: crumb/granular (roundish), platy (little flat plates), blocky (squarish), and prismatic/columnar (like rods).
Even though the weather might be great, it is important not to go out too early in the season to work your soils. Slow down! Working wet soil (as in the spring) destroys its structure. If the soil sticks to the shovel, it is too wet. Also, don't walk on wet soil, as this compacts the soil and hurts the drainage ability of silts and clays further.
Another factor is the Cation Exchange Capacity (CEC) of soils. Soils have a positive and negative charge in their ions. This indicates the ability of the soil to hold positively charged nutrients, such as potassium (K+). Fertile soil has the capacity to attract and hold these nutrients. Soils with large surface areas, such as clay and organic matter, have more CEC and surface area, and are therefore generally more fertile.
Sand has low CEC, silt has medium CEC, and clay has high CEC. So you are beginning to see how complex even just the texture of soil has on your ability to grow plants.
Most of the Helena area has a very high proportion of sand, though some areas do have heavy clay. Silt is comparatively scarce. We don't have the naturally nice food gardening soils of the midwest.
Soil pH
After texture, one must consider the pH balance of the soil, which affects nutrient availability.
The lower you go on the scale (6 decreasing to 2) you increase the magnitude of acidity. The higher you go on the scale (6 increasing to 12) you increase the magnitude of alkalinity. The sweet spot, the Holy Grail, for most food gardens is around 6.6.
Our soils are very alkaline. Most Montana soils range from 7 to 9 in alkalinity.
it is VERY difficult, nearly impossible to change the pH of soil. Partly this is because it is largely determined by the parent mineral material, the bedrock materials. You can't do much about your bedrock. Sulfur can slightly decrease the pH (makes the soil more acidic). Lime can slightly increase the pH (make the soil more alkaline).
The last thing we want to do in Helena is make the soil more alkaline, so lime is a no-no. But trying to alter garden soil alkalinity with "acidifying" liquid fertilizers is a lost cause.
Compost, hard work, and understanding your soil is key, not magic products some store is trying to sell. Regardless of what product people try to sell you, save your money.
I'll have more to share on soils next Friday!
I am going to summarize what each class covers here on this blog, for those who are interested and also for my own self-study. The class meets once a week for 8 weeks.
All those gardening books are great and helpful, but they pale in comparison to the local knowledge of a longtime gardener.
Guest Speaker: Dennis Flynn of Valley Farms (Helena Valley)
We had a guest speaker kick off the class, Dennis Flynn from Valley Farms, who has been growing primarily ornamentals and tomatoes here since 1974. This is a summary of what he told us.
The safest time to plant (transplants and direct seeding outside) in the Helena area is around Memorial Day (last of May, first of June). We are in a mountain valley after all. Our last freeze is usually in April but can go well into May, and the soil has to dry out and warm up some. Basil and peppers stay in containers until Father's Day, put in a wagon you move in and out of a protected area until then. Tomatoes work this way better too. Don't buy transplants and such from the big box stores. They aren't very well suited to local conditions. Go to a local nursery.
80% of people's problems growing here is in soil preparation. Helena's alkaline soils don't do well with adding peat moss. There is a product called Glacier Gold which is recommended. It is made in-state by a company that chips up mostly lodgepole pine slash piles, which makes this product very acidic (5.9). This helps balance the pH of our alkaline soils (we range 7.2-7.6 in local soils). 6.6 is the Holy Grail for soils pH balance. There is more on pH below.
Glacier Gold also has some of the streptomyces bacteria which is beneficial for adding soil life to our situation, which is very deficit in this regard as well. But don't try and grow stuff by adding alkaline soils under a pine (or other conifer) as this will harm both the pine and whatever you are trying to grow there.
Another common problem in our area is using too much fertilizer such as "plant food" or Miracle-Gro. Use these if you have to only on annuals, not perennials, and NOT on anything you want to produce fruit (such as tomatoes). These products are salts, and our Helena soils are too salty as they are. "Plant-food" is a marketing term, and a misnomer anyways, because you can't "feed" plants. Plants manufacture their own food through photosynthesis.
Proper composting is the key for most plants, including vegetables, not intensive fertilizers (except for particular species of flowers). Daniels organic fertilizer was recommended.
If you treat a plant too well, such as a tomato, with all kinds of commercial fertilizers, they won't fruit. You will get a huge plant but no fruit. Fruit are the plant's "babies" that the plant produces to ensure the survival of its kind, after it dies. If you pamper the plant, it thinks, hey, I'm gonna live forever. What do I need kids for?
We have trouble producing tomatoes sometimes in Helena. We get tomatoes to the green stage, then they sometimes die before ripening (of course part of the ripening problem is our very short growing season). If the tomato is green, but with a sucked-in black bottom, the plant was drawing its water from the fruit (fruit "babies" also serve as water reservoirs for the plant under stress, like a camel's hump). Part of the problem in this case is iron deficiency and too much salts (fertilizers make it worse). If you have a green tomato with small black spots, the problem is calcium deficiency.
Last year we had an early storm that killed a lot of the leaves still on the trees. Those leaves stayed on the trees all winter. (Leaves are not really green, that is just active photosynthesis- the real color of leaves can only be seen when photosynthesis stops- maple leaves are really red, and ash leaves are really yellow). But don't force those leaves off, let them leaf out naturally. The quick freeze didn't give the tree the normal time for the abscission layer to harden and force off the leaf in the natural cycle of things. If the leaf is forced off too early in the mistaken belief this helps the tree get new leaves, you are actually damaging the tree and it may not recover.
Never prune a birch or maple until much later in the summer here. This coming weekend (tomorrow) it is supposed to get into the 70s, and it is time to give all the evergreens a good watering. For successful gardening, you really need to understand the local conditions, and that means talking to local nurseries that have been operating for a while, and to older local gardeners who have all that experience.
That summarizes Mr. Flynn's portion, though he had a lot more to say, and he is a very successful local grower.
What is the Master Gardener program?
The Master Gardener program was started in the state of Washington in 1972, and has spread nationwide. It is generally administered by university extension offices in the various states, in response to increasing needs for gardening information. The Master Gardener program's goal is to create a resource bank of volunteers for local communities to assist in this effort. There are three levels of becoming a Master Gardener (I, II, III); I have just started the first one (Master Gardener I). At the end of each course, we are tested.
And then Master Gardeners of the various levels are required to serve as volunteers for the community based on the level attained (MG I = 20 hours, MG = 30 hours, MG III = 40 hours). There are various ways to do your volunteer hours, including giving talks, helping schools, helping at farmer's markets, creating community or demonstration gardens, writing articles, and helping with the Extension phone lines.
Soils I
The next section of the class was on soils, which was divided into two parts. Only part 1 was covered this first class.
Soil is a diverse combination of weathered rock fragments and minerals, with decaying remains of plants and animals (organic matter). You need to know your on-site soil profile (cross section of the soil strata (layers)). The appearance, color, and thickness of each is different from place to place.
The very top, the ground surface, is called the O horizon, and it is made of humus, the decaying layer of organic materials (insect husks, leaves, sticks, etc.)
Under that is the A Horizon, the topsoil, the richest darkest layer of soil, which is a zone of leaching soluble salts.
Below that is the B Horizon, the subsoil, which is the zone of accumulation of salts.
Beneath that is the C Horizon, the parent material. The portion nearest the top is the weathered parent material broken up by erosion, chemical action, etc. This goes through gradations (gradational contact area) to the fresh parent material below, the bedrock.
An ideal soil is half solid material and half pore space (the tiny gaps around the material). The solid material is mostly mineral (45%) with a little organic material (5%). The pore space is half water (50%) and half air (50%).
The 5% of organic material is further subdivided into humus (not hummus!) 80%, roots (10%), and organisms (10%). Humus (HYOU-muss) is organic material made up of decomposed plants, animals, and micro-organisms. Hummus (HUM-us) is an edible paste made up of garbanzo beans/chickpeas :-)
That 10% which is organisms includes bacteria, fungi, actinomycetes (which are microorganisms which resemble bacteria and fungi but are neither), and protozoa. There are 70 pounds or more of these little guys in every 1000 square feet of a lawn's root zone (about 10 feet by 100 feet, or 20 feet by 50 feet).
Soil Texture
The mineral portion (45%) of soil is made up of particles which are classified based on particle size as sand, silt, and clay. This is known as soil texture.
Sand (~2.0 mm) is easily seen as particles by the naked eye and is rough when moist and run between your fingers. There are different kinds of sand. Much of ours here in Helena is quartzite based, but on the beach in Hawai'i it is generally coral-based (except the black beaches which are of decomposed volcanic rock). Sand is excellent for drainage and aeration, but poor at holding water.
Silt (~0.05 mm) has a smooth consistency like flour when it is dry, but is hard to see as particles with the naked eye. The powdery stuff that made the Iowa Loess Hills is silt (loess is wind-blown silt). Silt is good all around, for drainage, water-holding, and aeration.
Clay (~0.002) cannot be seen as individual particles with the naked eye. It is hard when dry and sticky when wet. Clay is poor for drainage and aeration, but excellent at holding water.
The test to see if it was clay or silt when I was in archaeology is to grab a little moist bit between forefinger and thumb, and then pinchpush against it outward like toothpaste- if it made a little ribbon, it was more clay and if it crumbled before it got beyond the fingertip it was more silt.
The soil texture diagram (triangle) shows the sweet spots for combining the three textures, as sandy loam and silt loam, for growing garden plants. But be aware that you can't just add sand if you have too much clay. It doesn't work that way. You get clayish globs in amongst the sand. You need to add compost and slowly work that soil closer to where it needs to be, or go for raised beds etc., if your soils have way too much clay or sand.
To check your soils texture, just take a big jar and fill it 1/3 with a representative sample of your soil, and then top it off with water. Then add a drop or two of laundry detergent and shake. Let it settle for a day. The clay, silt and sand with resolve into different bands of texture (clay on top and sand on the bottom). You can then estimate your own soil's proportions by percentage, and compare it to the chart.
The effect texture has on soil is how it holds or drains the water/air mixture (field capacity). Plants need a happy medium- too much saturation, they drown, and too little, they wilt.
Structure of the particles is another characteristic that affects texture: crumb/granular (roundish), platy (little flat plates), blocky (squarish), and prismatic/columnar (like rods).
Even though the weather might be great, it is important not to go out too early in the season to work your soils. Slow down! Working wet soil (as in the spring) destroys its structure. If the soil sticks to the shovel, it is too wet. Also, don't walk on wet soil, as this compacts the soil and hurts the drainage ability of silts and clays further.
Another factor is the Cation Exchange Capacity (CEC) of soils. Soils have a positive and negative charge in their ions. This indicates the ability of the soil to hold positively charged nutrients, such as potassium (K+). Fertile soil has the capacity to attract and hold these nutrients. Soils with large surface areas, such as clay and organic matter, have more CEC and surface area, and are therefore generally more fertile.
Sand has low CEC, silt has medium CEC, and clay has high CEC. So you are beginning to see how complex even just the texture of soil has on your ability to grow plants.
Most of the Helena area has a very high proportion of sand, though some areas do have heavy clay. Silt is comparatively scarce. We don't have the naturally nice food gardening soils of the midwest.
Soil pH
After texture, one must consider the pH balance of the soil, which affects nutrient availability.
The lower you go on the scale (6 decreasing to 2) you increase the magnitude of acidity. The higher you go on the scale (6 increasing to 12) you increase the magnitude of alkalinity. The sweet spot, the Holy Grail, for most food gardens is around 6.6.
Our soils are very alkaline. Most Montana soils range from 7 to 9 in alkalinity.
it is VERY difficult, nearly impossible to change the pH of soil. Partly this is because it is largely determined by the parent mineral material, the bedrock materials. You can't do much about your bedrock. Sulfur can slightly decrease the pH (makes the soil more acidic). Lime can slightly increase the pH (make the soil more alkaline).
The last thing we want to do in Helena is make the soil more alkaline, so lime is a no-no. But trying to alter garden soil alkalinity with "acidifying" liquid fertilizers is a lost cause.
Compost, hard work, and understanding your soil is key, not magic products some store is trying to sell. Regardless of what product people try to sell you, save your money.
I'll have more to share on soils next Friday!