Accessing the Health of the Garden

Learning about accessing the health of a garden and its crops, including: fresh clues, nutrition, nitrogen, phosphorus, potassium, over watering, large critters and insects.


This sorry spinach patch was just itching to tell me that a pattern of sickness was afoot. Time to run down the list of possible nutritional/temperature/watering problems.


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Visiting the garden is what separates a gardener from a green thumb, learn about accessing the health of a garden. (See the garden photos in the image gallery.)

Gardens don't like to be neglected. Unlike a cat or dog, a garden can't jump into your lap or bark for attention. Gardeners have to initiate contact. One way to do that is to plant the garden on either side of a well-traveled path like between where you park the car and the house. Another way is to include a visit to the garden in the daily routine when accessing the health of a garden—get up, go to the bathroom, visit the garden, shower, eat breakfast . . .

A garden that is forgotten is a garden that has a diminished chance of doing well. There are, of course, exceptions, like the tomatoes we planted our first summer in Maine. Weeds grew up around them supporting them better than if we had staked them or put a wire basket around them. The high grass surrounding them protected them from the wind and no predators, either insect or animal, found them. We happened upon them just as the fruit was ripening and considered ourselves truly blessed.

That is the only success story I have of a neglected garden. Don't jump to the conclusion that the opposite of a neglected garden is one that needs constant care. I am a lazy gardener. If my garden demanded constant attention, I would probably try to find something else to make me feel useful while puttering. I'm pretty sure puttering is my favorite hobby, not gardening. The garden just happens to work well for a putterer. T think that if you did a survey of people who supposedly have a green thumb you would find that one characteristic was pretty universal—they visit their garden fairly regularly. Visiting is different from going out to weed or thin or stake the tomatoes or pick beans. Visiting is just dropping by to admire it, to see if the carrots have broken the ground yet, to see if there are tomatoes on the vine or if any are turning color. It may be the favorite place to watch the sun rise or set or to think about what the next day might bring.

I am going to take you on some of my visits to my garden over the years and you will get the idea. You'll learn how to deal with some of the various animals that also visit gardens and you'll see how this simple and pleasurable routine works.

When I was working a regular job I would come home during the growing season and instead of relaxing with a drink or cup of tea I would head for the garden. It was best if I changed my pants first as it is really difficult to spend much time in a garden without dropping a knee now and then. I think we ought to be called brown knees rather than green thumbs.

I also like to take a hoe with me. Unfortunately for my pants it was real easy to grab a hoe on my most direct path to the garden. The hoe was not for any purpose, you understand, other than to lean on and maybe to scratch at a few weeds and, since my garden is in sight of the road, to impress passersby.

The Virtues of Fresh Garden Clues

One spring day while visiting I noticed that the high-priced-seed hybrid broccoli that I had planted in a short row for transplanting later was up—tiny seedlings with two baby leaves each, each leaf smaller than the head of a tack. Lovely, I thought, with their dark blue-green color. On my next visit there were just stems, a row of quarter-inch-high stems no bigger than toothpicks. What happened to them? I looked carefully at the soil and could detect no footprints, no evidence of rabbits or woodchucks at work. My first visit had been three or four days earlier. The trail had grown cold. As any detective or reader of detective mysteries knows, the fresher the evidence the easier it is to solve the mystery.

I decided that flea beetles were the culprit. These small black beetles do have a decided fondness for this crop. In subsequent years I have been able to shoo the beetles away and cover the plants with a gauze net that protects them. After years of being too lazy to start these seedlings in flats indoors, I have come to the conclusion that it is actually easier to coddle them indoors, which really only requires watering. The first planting of broccoli was one of several failures due to neglect. Neglect is a pretty harsh term for just not visiting the garden every day which I seldom do unless there is a specific reason like keeping a close eye on newly emerged broccoli seedlings.

I have a specific reason to visit the spinach patch regularly after the seedlings start developing true leaves. I have had considerable trouble growing spinach. It just seems to disappear plant by plant in patches leaving me to harvest about one fourth of the area planted. The plants look fine and then one day several will be wilted and some lying on the ground, cut off. Cut worm is the first thought, but when cutworms are the culprit I can usually find the grub by scratching around near plants they have cut off. Not so in the spinach patch. Then I began to be able to detect slight wilting of upstanding plants. On further investigation I found that these plants would just lift out of the ground having little or no root structure. Some would look as though the root had been cut off about a quarter of an inch below the soil line leading me to suspect cut worm again, but I don't know of any cutworm that works on roots. Then others would come up with a shriveled root leading me to believe damping off or root maggots. It took years of casual observation to get to the point of really wanting to know. Now I have gathered a lot more evidence but I still don't know what is causing the problem.

However, with a lot of thinking and some reading and some more thinking I think I have a solution. My guiding premise is always "healthy plants in a healthy soil don't attract insects or diseases:' Whatever it is that is cutting back my harvest so severely, its cause must be a soil imbalance. But why is there only one crop that has a problem, Sherlock Holmes?

You see my dear Watson, I rely on natural fertilizers in my soil which are largely insoluble. For these fertilizers to become available to my plants they must be converted to a soluble form, which is what happens when the soil microorganisms break down organic matter. Over winter the soil microorganisms become inactive. To make the problem worse, winter snow and spring rain draining through the soil carries the soluble materials away. This is called leaching. Come spring, nutrients are probably pretty scarce, especially nitrogen, unless fresh manure has been spread. I have been fertilizing my garden with low nitrogen materials through the summer, expecting that the garden would always be ready to grow more wonderful vegetables. Spinach needs a lot of nitrogen.

But, Holmes, you never have any problems with peas and they grow even earlier in the spring. Don't they need nitrogen?

Ah yes, but peas are legumes and have the ability to fix nitrogen from the air. The next time I plant spinach I am going to use a naturally occurring water soluble high nitrogen fertilizer like dried blood or manure tea. Blood is expensive but I will be limiting the use to just the spinach rows mixing it in just before planting the seeds.

You may have gathered that I don't like to use soluble fertilizers even if they are organic and you are right. Too much rain will simply wash them away. What a waste not to mention the damage they may cause in the water. If you are having trouble grasping the solubility issue, try this experiment. Put a tablespoon of salt and a tablespoon of flour in a coffee filter. Pour water through the filter. If you catch the water and taste it you will taste salt. Eventually all the salt will be gone but the flour will remain in the filter. Now put the filter in the compost pile. Depending on the microbial activity, the filter and the flour will be gone in a couple of weeks to a few months.

As you can see, there are times when a detective's sensibility appeals to me, and without regular visits to gather clues, I'd still be scratching my head and offering eulogies to my wilting food.

More Nutritional Problems


The symptoms of plants with a nitrogen deficiency are slow, stunted growth, reduced size, and the leaves becoming pale green and then yellow, especially the lower portions.

While visiting the garden we become more familiar with our plants. If we know what the corn looks like in a good year, we are more likely to recognize a problem soon enough to do something about it. If I noticed that my corn looked anemic, pale yellow-green instead of the bright vibrant dark green I am used to seeing, I would side dress it with manure or seaweed. I will be surprised if that ever happens to me since I recognize corn to be a heavy feeder and I always make sure it has a special dose of manure or seaweed in the soil before I plant.


Phosphorus deficiency causes leaves to turn reddish purple on blades, veins, and stems, especially on the underside. When soil tests show that my garden is deficient in phosphate I like to spread rock phosphate to correct the problem. This is a ground rock that is not water soluble so it would not be good in an emergency. It is great for the long haul, providing phosphate for several years. If I needed a quick fix, I would probably use bone meal which is about 21 percent phosphorus.


The edges of leaves of plants with a potassium deficiency may curl or even turn bronze and dry out and they may get brown spots. This is most noticeable on the lower parts of plants. Since I burn several cords of wood every winter I always have wood ashes around which are approximately seven percent soluble potassium. You might wonder why I don't just spread the ashes on the garden when I clean out the stoves. First, soil tests indicate that my garden doesn't need any more potassium. Too much of a nutrient can be as problematic as too little. An overabundance may cause other nutrients to be bound up so the plants can't use them, for example. The other reason I don't dump the ashes in the winter is the solubility of the nutrient. If the plants need it, I don't want it leaching out of the soil. For those who don't have wood ashes, greens and is a commercially available natural product that provides about five percent potassium.

Those are just the three major nutrients. There are seventeen nutrients altogether that plants need. An expert can identify many deficiencies just by looking at the plants. I'm too lazy to try to figure that out. Besides, what would I do? I'd just kick myself for being too stingy with the manure or compost or cover crop rotation. I might try a rescue operation by side dressing compost or watering with a manure tea or foliar feeding by spraying seaweed extract. But I don't need to know which nutrient or secondary or trace nutrient is missing or in low supply. My approach is usually going to be some complex organic material to feed the soil and let the microorganisms sort out who needs what.

An Interesting Case

By visiting the garden regularly you are less likely to encounter rude surprises. I got a call one Saturday from a woman who was practically hysterical. "Something is eating my whole garden!" she exclaimed. "Please, can you come and tell me what to do." If she had something that was eating her whole garden, that would be news. My garden has been visited by everything from flea beetles to moose and none of them ate everything. The biggest problem with moose, by the way, is the size of their feet. Fortunately they have always been passing through because if they wandered around a little they would do a lot of damage.

Before grabbing my camera to photograph the phenomenon I thought it best to calm her down and get a little more information. What were they eating? Everything! Maybe she planted only the things woodchucks like to eat? It had to be an animal because insects are very plant-specific.

Finally I got this woman to tell me that it was on the asparagus, it was the size of her finger, yellow and fuzzy. I had to send her out to look at the culprit again. When she called the second time she told me that it didn't have legs. I thought we were getting close but the fuzzy bit still had me baffled. A slug, fuzzy? She did say fuzzy, not slimy.

I told her she could stick a sharp object like the point of a knife into them if she wanted to do battle right then and there. But that they probably wouldn't actually wipe out any of her crops, even the asparagus. Long-term, she needed to make the surface of her garden drier as well as the area around the garden.

Slugs don't eat much, not much of the garden that we like to eat anyway. They actually do more good than harm turning dead organic matter into plant nutrients But they can be a problem. They love to live in lettuce and cabbage plants, down in the lower portions where water collects. At one time I thought they ate tomatoes because I often found them inside holes in ripe tomatoes. With more frequent visits to the garden I learned that the slugs were actually getting into holes that crickets made in the fruit. Not that slugs won't eat a little of just about everything but their feeding is not the real problem. The real problem is that they are not pleasant to come across in the garden, and less pleasant to come across in the kitchen, and you really don't want to see them in the dining room. When I was selling lettuce and cabbage it became absolutely necessary for me to figure out a way to keep them out of these crops.

At that time I was mulching heavily, sometimes the whole garden, sometimes year around as Ruth Stout advocated in her books. Slugs love the cool moist environment under a mulch. I had tried a number of methods all of which worked to some extent. Slugs are attracted to malt. If you put out dishes of beer, they will crawl into them and drown. A tip for those who use this method. Place the beer traps at the edges of the garden. Otherwise I think they just keep coming in and when you run out of beer or get tired of emptying the traps, there are even more slugs in the garden.

Slugs like cool, moist places like under a board. I have put boards down in the garden paths and sure enough would get quite a collection of slugs under the boards on a sunny day. A bit of a bore disposing of them, though.

None of these trap methods suited me for an acre market garden so I decided to make it an environment they wouldn't like. I have not tried making a barrier of diatomaceous earth around the garden or around the lettuce and cabbage but I had read that the sharp edges of this powdery material would deter slugs. Instead I came up with a method that suits me best. I just make the area around lettuce and cabbage as dry as possible. That means no mulch, even on the adjacent paths. I cultivate the top of the soil, making it a dry dust most of the time. I also mow closely all around the garden. This makes a casual barrier for the slugs since the short grass dries out early in the day. The lettuce and cabbage patches have to be kept fairly free of weeds as weeds will collect moisture and shad the ground keeping it moist during the day. These considerations work most of the time. I had more slugs in 1996 than I have for many years. One, it was a wet summer. Two, I did not till the garden last year and left one section in mulch from the year before. Still, they were manageable.

The Dangers of Over-Watering the Garden

You have probably noticed that where you have scratched the surface of cultivated soil, it is drier than the soil left alone, but do you know why? Do you remember capillary action from high school physics? The teacher had several glass tubes with small bores, smaller than a drinking straw. I know because I just tried one. When the ends of these tubes were put in water the water defied gravity and rose in them. It rose highest in the smallest tube. This is capillary action. Another way to demonstrate it is with two panes of window glass. Hold them together and dip one end in water. If water doesn't rise between them, they are too tight together. Sprinkle a little dirt on them, just enough to hold them apart a little and try again.

When we cultivate the surface of the soil we break the capillarity, we make the spaces too great for the water to work against gravity. This dry surface is more than a good barrier against slugs. It also keeps moisture from coming to the surface where it will evaporate, thus keeping more moisture in the soil where the plants can use it. This is called a dust mulch. Another way to observe this phenomenon is to notice your footprints in a path you have cultivated or in the rows you firm when you plant seeds as opposed to the tilled or raked soil adjacent to the rows.

While I'm on the subject of moisture, I should mention the greatest hazard of visiting the garden: improper watering. Whenever I see someone standing in a garden or on their lawn, holding a hose and spraying water, I want to run up to them and say, "Stop, you are ruining your garden (or lawn)." If you visit the garden in the middle of a hot afternoon, you may observe some wilty-looking plants. That may be their self-defense against the heat of the sun. Please don't jump to the conclusion that the plants need water. Check them again in the late evening or morning. If they look like they need water then, they probably do. If you have been watering by hand, they probably do. The problem with watering by hand is that you simply don't have the patience to stand there for the three hours necessary to get the job done properly. The spritz you put on the surface will, at best, evaporate before the roots even know its there. At worst, the roots will learn to look for water close to the surface. Now you are in real trouble. Some day in August drive through a neighborhood where people spend weekends mowing, grooming and watering their lawns. The brownest lawns belong to the people who have been on vacation longest.

I will never water a garden more frequently than once a week and that only in a severe drought. I want the roots to go as deeply as possible. They are the foundation of a strong plant. Of course, I've got to put in a plug for organic matter. The more humus in the soil the more water it will be able to retain.

Duels with Larger Critters

Animals are the most important reason for visiting the garden. Generally the first visit an animal makes is purely by accident. It is just wandering around looking for food or just going from here to there or looking for a good place to make a home. In any case it is going to check out the potential food it comes across. In my experience animals generally take a few tastes first. Perhaps they have learned that something that tastes good may not sit so well on the stomach later. If it tastes good and there are no ill effects, they will be back for more. If you let them have two pleasant experiences, you are likely to have a serious problem on your hands.

Take the woodchuck I matched wits with for two years. If you don't know what a woodchuck is, it is what groundhogs are called some places including Maine.

Woodchucks and I go way back. When I bought this house 28 years ago they were living in the wood shed under the porch, used the drainage culvert to cross the road and, in general, thought they owned the place. I fenced my first gardens, until one built a home in the winter squash patch. It wasn't until we got a dog that they decided this was not prime real estate. It is amazing how canny animals are. Our most recent dog was nearing the end of her life three years ago and the woodchucks started moving back. They would taunt her, it seemed, coming closer and closer knowing that if they could coax her to get up and chase them they could beat her back to the hedgerow.

Two years ago the dog died and protecting the garden fell back on me. I had grown lax. I let the critter eat some lettuce. Then I put out some lettuce in a have-a-heart trap. Are you kidding? Eat wilted lettuce in a trap when fresh is right there? I had lost the initiative. I then sprayed my favorite Mexican seasoning on the lettuce and beans, figuring it would just be a matter of time before he or she tried those. But it rained and I wasn't visiting the garden as regularly as I should. The woodchuck was getting fatter and finding more escape routes. I strung an electric fence around the garden at woodchuck-nose-height. By now the peas were being harvested. At one point my son was in the garden grabbing a snack when he found himself eye to eye with the woodchuck, who was feasting on something in the garden, looking for all the world as if it was his or her garden. When Josh chased it he saw how it got past the fence. It just lowered its head and ran.

If the fence had been there earlier the woodchuck would have decided the garden was not a nice place. Having determined that the garden was, in fact, one of the nicest places for a meal imaginable, he or she was willing to risk a little shock.

So I put up another strand of wire and I seasoned the plants again. The seasoning, by the way, is about a tablespoon of liquid detergent and a tablespoon or more, depending on how angry I am, of Tabasco in a watering can of water. Animals in Maine, at least, do not like highly spiced food. This works especially well if this is the first taste they get from your garden. Almost as well if it is the second. Past that and you may have more convincing to do.

I feel badly that I misled this animal into believing that we could be partners in the garden. The next spring when he started foraging again having spent the winter under my shop, I gave him or her one more chance. I went around to all the escape routes I could find—under the porch, the road culvert, a hole in the hedgerow and the den under my shop—and plugged them up. I shot at him once but missed and he ran off to the barn. But still he returned. By this time I had determined that it was a lone male planning to establish an attractive place for a mate. He tempted fate one too many times.

I know that it will distress some people to think that I killed a small furry animal. I would rather not have had our relationship end that way. Some people tell me that I should plant enough for the animals and myself. A nice idea, however, I can assure you that all that would do is increase the population of animals and I would have to expand the garden every year to accommodate the rising population. I want animals that eat my vegetables to stay out of my garden and all animals other than humans to stay out of my house. Anyone who allows mice and t rats to run unmolested in their homes is welcome to condemn me for killing the woodchuck. Please remember that I do "take responsibility for that killing. It was my fault because I allowed the animal to— become familiar with my garden.

The electric fence around the gar den was wonderful later in the season when raccoons and porcupines frequently get into the corn. There is a deer that has found my garden and comes back every year after the first frost. I strung an additional strand of wire about three feet off the ground to see if I could persuade the deer that I had moved and been replaced by a nasty person. One morning I found the fence down and some deer tracks in the garden but no damage. The tracks looked like a deer running rather than wandering. The fence had been put up flimsily so it was no surprise that it was down. No deer last year.

Visiting the garden may be most important for animal control but there are all sorts of things you may come across that will save time and make for a better garden if caught at the right moment. If you are staking your tomatoes, you will probably do a much better job of tying them to the stake before they flop down with twisted stems. You'll know when the corn and zucchini are ready to harvest. You'll catch in sect damage early and be able to monitor it without panicking. And what gardener can casually walk through a garden, any garden, without pulling a weed or two?