A comprehensive gardener's guide to soil microbiology including pH levels, soil texture, and the best plants for your yard.
It is important for gardeners to understand the dirt they are working with.
An old farmer told me years ago that it was time to plant corn when it felt comfortable to walk barefooted in the garden. That was right up my alley, as I greatly dislike shoes. Granted, in our modern world of pavement and broken glass it's not always practical or safe to walk without shoes. Ah, but in the garden. When I stand in the garden in bare feet I feel plugged into the earth. It seems as if my feet are communicating with the soil in some way. The soil pushing up against my flat arches and molding to my feet is very comforting ... I would even say mystical but then people would start laughing.
I believe we know more about the surface of the moon than we know about the surface of the earth — not because we haven't tried to understand what is going on immediately under our feet, but because there is so much going on. Soil texture and pH levels vary all across the board, not to mention the rich, complex cycle of decomposition that is constantly in play.
A number of years ago I read a book entitled Soil Microbiology by Selman A. Waksman, Professor of Microbiology at Rutgers University. It is a compilation of research that had been done on soil microbiology up to that time. What I found most fascinating about this book was the frustration the scientists experienced as they struggled to understand soil life by counting microbes. The damn things would change before they could count them. The minute they disrupted the soil by taking a sample or separating elements from it, the soil microorganisms would change.
"The soil is not a mass of dead debris, merely resulting from the physical and chemical weathering of rocks; it is a more or less homogeneous system which has resulted from the decomposition of plant and animal remains. It is teeming with life. The numerous living forms which spend all or part of their life in the soil range from the sub-microscopic viruses and phages, through the microscopic bacteria, actinomycetes, fungi, algae, and protozoa, to the lower animal forms, the worms, insects, and rotifers, many of which can be seen and recognized with the naked eye. These organisms, comprising both the living forms and their dead bodies, as well as the products of their decomposition, such as carbon dioxide and organic acids, interact with the rock constituents to give rise to soil. The soil thus gains the characteristic properties that make it a suitable medium for plant and animal life," Waksman writes in the preface of Soil Microbiology.
As I stand barefooted in my garden there are more individual living microbes under just one foot than there are people in New York City ...and I don't have especially large feet. That is a bit more than I can comprehend. It is time to take Thoreau's advice and "simplify."
The simplest way to begin studying your soil is to understand its texture. Rub some of it between a finger and thumb. If it is gritty, your soil is sandy. If it is greasy feeling, you have a clay soil. If you can't make up your mind, you have a silt. All you are doing is putting a name to particle size.
A sandy soil will let water drain through it quickly. This is great in the spring when people with heavier soils are waiting for the garden to dry enough to work, but it is a problem in a dry spell. The particles of a clay soil are so close together that water has great difficulty getting through at all. Not only is a clay soil the latest to work but if you work it early you will turn it into a dumpy mess that you will regret for the rest of the summer.
To test my soil to determine when it is ready to work, I scoop up a handful and squeeze it into a ball. Then I hold the ball between a finger and thumb and squeeze. If it crumbles, the soil is ready. You can imagine how easily a ball of sand would crumble if you could even get it to hold together in the first place, while a ball of clay would fiercely resist breaking apart.
With the addition of organic matter, our soil becomes loam, whether it is sandy-loam, silt-loam, or clay-loam. The organic matter (mostly plant and animal residue) breaks down through the action of, you guessed it, micro and macro organisms. Now we are back into the complex stuff again, so rather than do that, let's just accept that the plant and animal material becomes humus and that humus is magic stuff.
Magic? Yeah, magic! The problem with sandy soil is that it doesn't hold water, won't hold together, and has too much air. Humus binds the large particles together and fills in the air pockets with a sponge-like material that will hold water. Reasonable, not magic. But get this: The problem with clay soil is that it holds water like a bathtub, it sticks together like bubble gum, and the particles are so close together that plant roots can't breathe. Humus pushes the particles apart with a sponge-like material that allows air and water to move between the particles.
Of course humus also improves a silt soil. In other words, we should be adding organic mater to our garden soil all the time to make it better. Why did we have to know if it was sandy or clayey? We didn't. However, sometime you may be in a conversation with someone and the topic of soil may come up and they may ask you what kind of soil you have. You will know and they will not be able to pull any of that superiority stuff on you. They wouldn't have asked you for any other reason unless you were complaining about not being able to work the ground until late in the spring or about having to water the garden when it was dry.
The next pretty simple thing we can get into is the soil pH, the scale by which acidity-alkalinity is measured. The numerical values of the scale run from 1 to 14. Seven is considered neutral, below 7 is acid, and above is alkaline. You can get a quick idea of the pH of your soil by just giving it a taste. A sour soil is acid, a bitter soil is alkaline, and a sweet soil is neutral. You are looking for a fairly sweet soil with just the hint of sour.
You can get more scientific by buying a soil test kit or sending a sample of your soil off to the cooperative extension at most state universities, and they will be tickled to serve you in the hope that you will become a supporter in these times of budget cuts. In Maine a soil test costs $10 per sample and it takes about three weeks to get the results back. The Cooperative Extension will also give you recommendations for correcting the pH. It is really a worthwhile service, but only if you have the test done early enough in the year. Grab a handful now and have it tested before planting.
If you were my neighbor and you came to me in the spring asking what you should do for a new garden, I would tell you that your pH was probably below 5.5 and that you should spread 150 to 200 pounds of limestone per 1,000 square feet of garden. However, if you live in Lincoln, Nebraska, that is terrible advice. What I am suggesting is that you seek advice in the neighborhood if you need some instant guidance.
The goal is to get the pH to about 6.5 for most crops. You may find a listing of vegetables that will give you optimum pH for each plant. Forget that, except for perennials like the berry patch which can stand to be more acidic, the asparagus patch which can be a little on the alkaline side, and potatoes... which I'll get to later.
Let me go back to my off-the-cuff recommendation to my theoretical new neighbor. In addition to the lime, I would recommend that he or she spread manure (mixed with a bedding of straw, wood shavings, etc.) in generous doses. Back to the magic. For some strange reason, humus broadens the range of pH within which plants will grow well.
By the way, pH means hydrogen-ion activity. If you thought I was on the fringe of my understanding with microbiology, I'm beyond the fringe when it comes to ions. Ions are electrically charged atoms or molecules formed by the loss or gain of one or more electrons. Ammonium (one of the forms nitrogen can have), potassium, calcium, magnesium, and most micronutrients are cations which means they have a positive charge. Soil particles are negatively charged and since opposites attract, these nutrients attach themselves to soil particles. Plant roots moving through the soil give off hydrogen ions which are positively charged. These hydrogen ions are very pushy. They attach themselves to the soil particles and bump the nutrient off. The nutrient, now a positive charge looking for a place to go, attaches itself to the root and is then absorbed into the plant.
The bottom line is that you want to have a lot of surfaces in the soil with negative charges that will latch onto the positively charged nutrients. A pH in the neutral range improves the cation exchange capability of the soil. Guess what else will make a great improvement? That magic substance, humus. It increases the surfaces to which cations can attach themselves while they wait to be bumped by a hydrogen ion.
Nitrates (a form of nitrogen that plants can use) and phosphates do not attach themselves to soil particles electrically. They are water soluble. Plants absorb these nutrients with their water. Humus is there again playing a role in holding nutritious water in the topsoil where the roots can find it.
This is really fascinating stuff, but it is a lot more than you need to know. Just add lots of organic matter and correct the pH every two or three years. If the pH needs to be raised and you add crushed limestone, the limestone will act like slow release capsules over a three year period.
Potatoes are the only crop I think of when I think of pH. Among those millions of soil microorganisms there are several that cause scab on potatoes. Scab is to a potato what a cold sore is to us, an unattractive rough spot. Potatoes with scab can be stored just fine and they are fine eating but their appearance doesn't stir the appetite so they typically can't be sold. You might not want to put a scabby baked potato on the table either.
But scab is easy for commercial growers to control. At a pH below 5.3 the number of scabbed tubers drops below 2 percent and below pH 5.0 there is no growth of scab organisms. Because potatoes will grow well at a pH in this range, all the grower needs to do is keep the pH below 5.3. We gardeners are trying to grow several crops in the same soil, rotating them each year so the same plant is not looking for the same nutrients in the same place year after year. What to do?
The Maine Soil Testing Service has this advice: "Grow scab-resistant varieties: Russet Burbank, Superior, Norland, Belrus, or Waseon. Reserve an area for potatoes and grow in rotation with sweet corn. Maintain reserve area at pH 5.5, remaining garden at pH 6.5." That was on the soil test results of a sample I sent last fall which showed the pH in my garden to be 6.6. Sometimes I do plan ahead.
I was surprised to find the pH so high since I have not added lime for several years. I thought that it would be used up or leached out of the soil by now and that I would have to replenish it. Not so. I called Bruce Hoskins who tested my soil al the Maine Soil Testing Service. He said that the pH was probably staying up because I was using natural fertilizers. It is the chemical fertilizers that have the greatest effect on lowering the pH. I asked him about acid rain and he said its effect was minimal. I may never have to buy or spread lime again. Good news for a lazy gardener.
That still leaves me with the problem of scab. I used to work liming into my rotation. I knew where the potatoes were going to be planted and I didn't lime that area. According to Bruce's directions I should have kept the lime off the potato and corn plots and followed the corn with potatoes in my rotation. There are some other crops that can't stand a pH down to 5.5. Beans, Brussels sprouts, carrots, collards, cucumbers, eggplant, garlic, kale, kohlrabi, parsley, peas, peppers, pumpkins, radishes, rutabaga, squash, tomatoes and turnips join corn in this range Chicory, endive, fennel, shallots, sorrel, sweet potato and watermelon join potatoes in tolerating a pH as low as 5.0. Corn is the most logical choice because it takes up a lot of area — as do potatoes — but if you are trying to figure out a four-year rotation in which you use lime or ashes to raise your pH, any of these would be good choices for the areas that were not limed.
I haven't worked up a garden plot for this rotation, but the grouping might go something like this. Add lime or wood ashes in one fourth of the garden and plant beets, broccoli, cabbage, cauliflower, celery, chard, Chinese cabbage, leeks, lettuce, muskmelon, okra, onion, parsnip, salsify, soybean, and spinach in this area. The second and third years, plant corn or a mix of the crops listed in the previous paragraph in this area. The fourth year after spreading the lime, plant potatoes.
While I keep records of what I plant where each year and how the garden has been fertilized, I have not kept records on the state of the crop. We have had very scabby potatoes some years and other years they have been beautiful, so beautiful I have given them as Christmas presents. Last year they were scabby and they were planted in, newly turned sod which received no ashes or lime and was mulched with leave which are acidic. Past experience led me to believe the pH would be low, though I didn't test it. With a low pH there should have been no scab, I thought. It is one of those mysteries that may never be solved. Unsolved mysteries in the garden abound. I'm sure it is one of the reasons I have never become bored with gardening.
So much for the pH. Now it's time to get into the rest of the chemistry lesson. Plants need 16 chemical elements for healthy growth. If you have been buying chemical fertilizer, you are well aware of the three that plants need in greatest quantities and that are not automatically replaced each year. These are nitrogen (N), phosphate (P), and potassium (K), good old N-P-K. When a bag of fertilizer says it is 5-10-10 it means it has 5 percent nitrogen, 10 percent phosphate, and 10 percent potassium. The next three most important elements are calcium, magnesium and sulfur. You have probably taken care of calcium if your pH is in the proper range. Sulfur is very rarely a problem. Magnesium is added to some commercial fertilizers in areas where deficiencies are common. Those are the six macronutrients.
There are seven micronutrients or trace elements: iron, boron, manganese, zinc, molybdenum, copper and chlorine. These are indisputably necessary to the healthy growth of plants. Fortunately they are available in most soils. The most likely way these elements might become a problem is if the pH is above 7.0 or below 5.0 because at these levels they can become either bound up and not available or too available and potentially toxic. How can you be sure trace elements are available to your garden plants? Easy! Just use the magic ingredient. Keep the humus level up.
One of the problems I have as an organic gardener is that my answers to problems can be boring: witness the above. That is why I latch onto bits of information or delve into controversy. An example of the former is that the most recent trace element discovered to be absolutely necessary for the healthy growth of plants is molybdenum. For controversy, selenium was recently "discovered" to be essential to the healthy growth of plants. This is in dispute, however. It was tremendously difficult to determine whether or not any of the trace elements were essential because the amount needed is so small and because it is very difficult to grow plants in a completely controlled environment. Scientists had a terrible time eliminating single elements to make valid experiments. Some elements may even be carried over in the seed or seed coat.
The importance of selenium may be a dispute, but not whether it is necessary to the healthy growth of mammals. And mammals get it through eating plants.
I said there were sixteen essential elements and, if you have been keeping count, I only named thirteen (fourteen counting selenium). The other three are the most important, and constitute most of what plants are. Hydrogen and oxygen in the air and as water comprise about 90 percent of the plants in the garden. Water is essential for the uptake of some nutrients, most notably nitrogen in the form of nitrates and phosphates.
I have saved the best for last: carbon. There is carbon in all plants and animals. Forty to 50 percent of organic matter is carbon. Organic chemistry was originally the study of plants and animals and later expanded to include all chemistry involving carbon. Only .03 percent of the air is carbon yet all plants must take carbon from air. We exhale carbon dioxide and plants take it in and "exhale" oxygen.
When organic matter decays, carbon dioxide is released into the air. Some studies suggest that it may be better to incorporate organic materials directly in the soil rather than compost them because this puts more carbon dioxide in the soil.
"Chemistry, soil microbiology, geology ... why do I need to know all this?" I hear you wondering. You don't. You can go to the seed and feed store and tell them you want to grow a garden. They will probably ask you the size and then sell you some fertilizer, probably a chemical 5-10-10. If they are good sales-people, they will sell you some lime, perhaps hydrated so that it will act faster. That will take care of the chemicals unless they suggest a pesticide to kill anything that might eat your plants. If they are into the geology of the soil they might sell you some peat moss or other sterile bulk material to improve the soil texture. You will probably have a reasonably good garden. It will be better if they tell you how to side-dress the chemical fertilizer. They ought to tell you something about the insects so you don't spray beneficial ones.
You don't need to know all I have put down here to garden organically either. I just wrote it to show off and because I think it is interesting. I also think it is great fun to know that I can grow a garden in this complex stuff called soil which is in some ways very mysterious. I love being so close to something that is still baffling scientists.
It has been 14 years since I last tested my soil. The pH was 6.7 then. Potassium has gone from medium to excessive, and magnesium from medium to optimum. Phosphorus dropped back from excessive to optimum as did calcium. Those are not big changes. This means I can pretty much continue what I have been doing. The one change I will make is to keep ashes off the garden and out of the compost until another test tells me calcium is needed.
My first soil test in 1972 showed me that the soil was medium to low in all nutrients and had a pH of 5.3. I corrected the pH with ground limestone, as recommended on the soil test. Then I spread cow manure mixed with hay and tilled that into the soil before I planted. The next year, I spread seaweed for nitrogen and potassium and rock phosphate to bring up the phosphate level. The next year I spread seaweed. All three years I mulched the entire garden. Then I had the soil tested again.
The pH had only risen to 5.7 but all nutrients but calcium were optimum or close to it. The garden was doing very well in spite of the low pH, but I limed again to correct it. In all the soil tests since, the pH has been between 6.3 and 6.7. If I had it to do over again, I don't think I would lime a garden with 5.7 pH if it was meeting or exceeding my expectations. The humus, our magic ingredient, widens the band of pH in which plants will do well. Right now I'm happy to see the pH drop back a point. I wouldn't want it to just keep climbing because you can definitely have too much of a good thing. Remember that a pH above 7.0 will bind up some of the micronutrients.
My soil test says that 8.2 percent organic matter is excessive. I have had organic matter test as high as 11 percent and I haven't had any reason to feel that it was a problem. However organic matter can present a problem: nutrient deficiency.
I had long heard from the proponents of chemical fertilizers that organic fertilizers would rob the soil of nitrogen, but I had no such experience. Then one year I looked out across the garden and saw some clearly unhappy plants. Since I am pretty casual about the way I spread manure and other materials, I am used to having spots that are not as robust as other spots. But this was a large area. Rows of vegetables going from four or five inches in height to two or three. Full rows dwindling to scattered plants in the row. The closer I looked the less I understood. Then I went upstairs in the house and looked out at the garden and saw that the poor growth was in a semicircle on one edge of the garden and I knew what had caused the problem.
That winter, someone had called to say that an elm stump had been ground up in front of their house. Did I want the chips? I am a collector of organic matter so I hopped in my truck and went of the get the chips. For lack of a better plan I parked the truck at the edge of the garden and spread the chips as far as I could pitch them from the back of the truck. They were tilled into the garden along with everything else in the spring. Out of sight, out of mind.
What happened in this part of the garden was that all the soil microorganisms went to work breaking down the carbonaceous material, the wood chips. There was a lot of work to do and so more were needed. It takes nitrogen for the population of microorganisms to explode, so when my plants went looking for nitrogen in the soil it was all being used. Eventually balance was restored. Then, as the larger population of microorganisms finished the job of decomposing the wood chips, they died and became a source of nitrogen to the plants again. The process took too long for my garden that year, however.
If I had been aware of this process, I could have added some nitrogen. The ratio of carbon to nitrogen should be about 30 to 1. Most carbonaceous materials are added to the garden with manure which provides the nitrogen necessary. The only material that I worried about was horse manure. Horse owners like to keep their animals very clean and they usually use wood shavings or sawdust. The carbon-nitrogen ration of sawdust is about 400 to 1. And horse manure is only about half a percent nitrogen: you can see why I was concerned. You can try doing some math with those figures to come up with the ratio of horse manure to sawdust if you like. Myself, I just spread some of the stuff to see how it would work. Horse manure with wood shavings or with sawdust has worked fine in my garden. I don't guarantee that you won't experience a nitrogen deficiency, but, so far, l haven't.
If you do find yourself in that situation, side-dress the crop with blood meal or cottonseed meal. These are available at most garden stores and will provide a quick fix of nitrogen in an emergency. Remember that the current deficiency is not a loss, just a delay.
Which brings me to the reasons I don't use commercial, water-soluble fertilizers. First, because they are water soluble, they won't stay where you put them. You put them in the topsoil where the roots of your plants need them. When it rains these water soluble nutrients leach down below the root zone, and eventually into the groundwater where you really don't want them. Those who will try to sell you these fertilizers will tell you that they are available while most of the phosphate in rock phosphate is not. True, but that is a plus. The rock phosphate stays where you put it and the soil acids and microorganisms make it available to the plants as they need it.
The other problem I have with chemical fertilizers is that they don't need soil microorganisms. You know what happens to the soil microorganisms when they aren't needed. They die. They disappear. Chemical fertilizers make it possible to grow crops in a basically dead soil. Soil like this has poor tilth; the structure is not good because it doesn't have that magic ingredient, humus. Sandy soil will lose more water through it and clay soil will have more water run off of it. A garden managed this way will need much more care because it doesn't have the structure to support itself. It can't retain water in wet periods for the dry periods.
Perhaps worst of all for this gardener, is the feel of a dead soil under his bare feet. A clay soil feels like pavement and a sandy soil feels like glass. I also take great pleasure in letting nature feed and water my garden all summer, leaving me with nothing to do but protect it from animals, harvest, and eat the crops as they reach perfection.
Slugs — those wonderful slimy snails-without-shells — were a serious problem in my garden for several years. They are good at breaking down organic matter and they eat very little of the growing vegetables in the garden but they really tend to turn off a salad eater. Lettuce, one of my favorite crops, is also one of theirs. They need wet places. Drying out is death to them and it is always very moist inside lettuce and cabbage plants. The large leaves collect the morning dew which frequently runs down to the lower interior of the plant making this a wet place through the hottest days.
I tried everything I could think of or had read about to get rid of slugs. If you have had the problem, you are familiar with the beer traps. Slugs are attracted to a dish of beer and they will drown in it. What I finally figured out was that by putting the dishes of beer in the garden I was attracting slugs from afar. The more I collected in my traps the more there were. Hint: if you are going to use traps, place them on the edges of the garden so slugs will be drawn away rather than into the garden.
I put down boards in the walkways. Slugs would collect in this damp place during the day. I would go out with shoes on, turn over the board and tramp on the slugs. Messy. But I could turn back mulch just about anywhere and find clumps of them. In frustration I would drop handfuls of ashes on them to dry them to death.
Then I finally found a comprehensive solution. First I till the whole garden in the spring which makes it a bit of a desert for slugs. Essentially, any that survive the tilling will leave. Next I mow the grass around the garden and keep it mowed. Tall grass is almost always wet near the soil. Short grass dries rapidly in the morning sun. Third, I don't mulch the lettuce or cabbage. By controlling weeds through cultivation around these crops, the slugs find the environment inhospitable. There are still slugs around the garden and some in the garden but this method has eliminated them from salads and coleslaw.
Hydroponics is the growing of plants without soil in a nutrient solution. Plants may be suspended; their roots in water, with a collar, strings, or some other support. Air needs to be bubbled through the water and nutrients provided to the roots in solution in the water. Are agricultural fields without humus, earthworms, and other soil organisms which nutrients are provided by water-soluble chemicals hydroponic? I can't see much difference between a hydroponic system using sand as the medium and a dead field that is irrigated.
You could trace hydroponics back to the hanging gardens of Babylon or to the early experiments by scientists trying to figure out what chemicals plants need to grow. The word "hydroponics" was coined in the 1920s when the process was developed as a realistic approach to growing plants. It has been touted as the inevitable way the majority of food will he grown in the future as population growth creates the need for more food while taking more land out of agricultural production. Hydroponics ("Hydroponics" is both the singular and plural of the word) potato plants went in orbit a couple of years ago in a test to see how they would perform in space.
At the Big Pineapple in Australia, after a train ride through pineapple fields and a trip through macadamia orchards in a string of nut-shaped trolley cars, the tour concludes with a boat trip around a hydroponics greenhouse. At Disney's Epcot you can see plants moving through the air on conveyors with their dangling roots receiving nutrients through mists of water being sprayed on them.
While someone as grounded in the soil as I am is not particularly fond of the Disney World approach to growing, there are some undeniable facts that favor gardening without soil. Plants are fed most efficiently in this manner. They will also grow faster and are likely to grow larger. This comparison supposes that soil-grown plants are not living under optimal growing conditions which, admittedly, is likely. Most systems control all aspects of the plant's grower, nutrients, temperature, light, and humidity.
Lastly, some will say that soil-less gardening is easier, though I think that is a matter of personal taste. I don't find anything I do with my soil to be work. For me, measuring and mixing chemicals, lifting and lowering a bucket of water each day, and cleaning the equipment would seem like work.
Nutrients are the key ingredient. Scientists discovered most of the nutrients necessary for plant growth by experimenting with growing them in water and adding chemicals to see what would happen. Now anyone who wants to grow plants hydroponically can buy properly balanced chemical solutions from agricultural supply stores and follow the directions on the label.
Is hydroponics the wave of the future? Many thought so 65 years ago. The interaction of the chemicals with various materials caused some problems. Some of the materials used as a medium for holding the plants absorbed nutrients while others released them. The same happened with containers and piping. Plastic solved a lot of those problems when it came along and hydroponics saw another growth spurt. Just this brand of problem-solving has resulted in the fact — either astonishing or thunderingly unimpressive, I can't decide which — that 2 percent of all the tomatoes sold in the U.S. are hydroponically grown.
Five years or so ago supermarkets in Maine sold lettuce with the roots in a plastic baggie. It was fun to buy locally grown lettuce in the winter though it was a bit expensive. It was also tasty. We don't mind spending more for a reason. In this case there were two reasons: We were getting good quality and we were supporting a local grower. Two years later it disappeared, but our bias against "dead" agriculture was removed forever. MOTHER EARTH NEWS first conducted a taste test of traditional vs. hydroponically grown vegetables in 1976 and we have never found a significant flavor difference between the two.
But, wait a minute, aren't I dyed-in-the-wool organic? Aren't hydroponics chemical? Am I advocating a chemical method of growing food? Yes to all three questions.
I grow organically because I like doing it that way. It is more challenging and more fun for me to get great results without using chemicals. The icing on the cake is that there are some who say it can't be done. I love to do things that "can't be done."
I advocate growing organically because chemicals allow some people who shouldn't be allowed to manage soil at all to deplete it of organic matter, to poison the soil, air, and water with agricultural chemicals, and to sell food with potential poison on them.
Hydroponics does not contribute to soil depletion nor does it spread poisons around indiscriminately. Hydroponically grown vegetables may have pesticide residues, but because they are usually grown indoors, most of the insects can be controlled with barriers. Finally, hydroponics ultimately uses fewer chemicals and less water than conventional agriculture does.
Nutrient solutions can be made from natural sources by leaching good compost or manure and collecting the "tea." If your definition of organic is "without manufactured chemicals," you can have organic hydroponics. In a head-to-head test of commercial, artificial hydroponic solutions, and naturally obtained "teas," MOTHER EARTH NEWS has found that the commercial solutions caused the plants to grow slightly faster, but the naturally-fed plants were significantly less prone to wilt during the hottest part of the day. We'll take the natural, thanks.
For the past 65 years, All-America Selections (AAS) has taken the guesswork out of finding flower and vegetable varieties that are reliable, productive, and that show marked improvement over other varieties currently available. There are four award winners for 1998.
Bright Lights (Swiss chard) offers a striking array of colors. Plant stems can be yellow, gold, orange, pink, violet, or striped in addition to the standard red or white. It also has a milder chard flavor. Bright Lights seeds are normal, multi-seeded fruits typical of beets or chard, and are usually sown in prepared garden soil in the spring or fall. Chard is easy to grow from seed and is widely adapted to a variety of growing conditions. Young plants may tolerate light frosts without damage. Harvest can begin in about 4 or 5 weeks for young salad greens, but either young or mature leaves should be taken just above the soil line so that the plants can grow back for multiple harvests.
Victorian Rose (Impatiens F1) is the first impatiens with consistently semi-doubling flowers. The unique, distinct qualities of Victorian Rose are the semi-double blooms and the number of blooms. Its flowers contain extra petals, adding depth to each rose bloom. More importantly, the flowering capability exceeds that of similar plants. This old-fashioned rose is a soft, muted color which combines easily with other annuals, and initial AAS trials indicate good season-long performance as well. Victorian Rose performs best in a shady garden and will adapt to any container. Like all impatiens, it needs little care in the garden, only sufficient water to maintain color.
Sweet Dani Lemon Basil is an improved aromatic herb, most noteworthy for its strong lemon scent. The scent is released when the plant is lightly touched, and was accentuated by the purposeful breeding of plants with high essential oil and citral content. Easy to grow from either seed or plants, Sweet Dani needs warm temperatures for rapid growth. In the full-sun herb garden, its plants are uniform, fully branching to provide more leaves for harvest. Gardeners can expect a mature plant height of about 26 inches with white flower spikes appearing late in the growing season, and the plants can be cut back or trimmed for harvest several times with good regrowth.
Prism Sunshine (Petunia F1) represents numerous improvements, but the most significant to us is flower color. This single grandiflora flower has a creamy yellow color that neither fades nor blushes pink under stressful garden conditions. The deep green foliage contrasts with the large 3 to 3 1/2 " yellow flowers. Prism Sunshine plants are vigorous, flowering freely throughout the growing season. Plants may spread from 15 to 20 inches in the garden, depending on the available nutrients, sunshine, and moisture. It seems to thrive in a full-sun garden. LIke the victorian rose mentioned above, it is adaptable to container gardening.