Growing zone, sun, soil and water are garden basics and the Big Four of the gardening world. You have no real control over any of them, but you can influence, adjust and manage them to your benefit. Of the latter three, siting your garden for the best sun and water conditions is the most important, because you can build up just about any soil. Too little sunlight makes for spindly plants and if you have to haul water to your garden, the thrill of raising your own food will wear off almost immediately.
The US Department of Agriculture has spent a lot of time and money mapping the official gardening zones in the US. What zones primarily affect is the length of the growing season and the usual temperatures. They don’t affect rainfall. The higher the zone number, generally speaking, the warmer the zone and the longer the growing season. The difference between Zone 8 and Zone 9 isn’t necessarily all that big, but the difference between Zone 2 and Zone 9 is significant. However, the USDA zones primarily focus on winter temperatures, not summer heat. So you can have a Zone 8 with a cool summer (like Seattle, Washington) or a Zone 8 with a warm summer (like Charleston, South Carolina), which means very different growing conditions. Zones also don’t take daylight into account – important when you’re growing something like onions that need long days to form bulbs. Depending on topography, you can also have an island of Zone 8 or Zone 6 in a Zone 7 area. These microclimates may be what allow your neighbor to grow tomatoes earlier than you or to have an orange tree in the garden. You can affect these microclimates by careful siting or other tricks. When the Romans moved into Great Britain, they quickly found that in order to grow some of the plants they brought from Italy, they had to create microclimates. As an example, they would build a stone wall around a garden, which helped to keep out cold winds. The stones also stored daytime heat and radiated that heat back out at night. In addition, the Romans would plant heat-loving plants like fruit trees or grapes against the stone wall and trim the branches for maximum sun exposure (a technique called espaliering). These microclimates helped keep the more tender plants from freezing.
The garden books will all tell you that your garden should have full sun all day. Our kitchen garden is right below the house. It’s not ideally sited, because it’s partially shaded at different times of the day and year. It’s on a south-facing slope, however, which makes up for the shade. The plants in most of this garden get at least six hours of full sun even in winter, which is enough to keep them producing well. If you’re stuck with tall trees you can’t take out (neighbors tend to take a dim view of you chopping down their landscaping) or other features that prevent the full-sun-all-day ideal, aim for as much sun as you can with morning sun and afternoon shade. Plants are larks. Like those of us who bound cheerfully out of bed early in the dawn, they prefer morning light. The areas that tend to get shaded are best for growing things like leaf and root crops, which actually appreciate a little shade, especially in the dog days of summer. If you have some perennial plants, such as asparagus, artichokes or rhubarb, those will also do OK in afternoon shade.
Unless you live in an area that gets rained on in the summer, you will probably want to water your garden. Many of the Southwest tribes, such as the Pimas and Navajos, were able to raise crops in the desert. Although I might be able to get by using some of the techniques developed by desert-dwelling Indians, it would take much more land than I want to put into production.
However, if you have lots of available land, highly fertile soils and live somewhere that has a relatively short dry period (I have a six-month or longer stretch with no water), you may be able to practice dryland farming. Nita Wilton (of Throwback at Trapper Creek fame) has a 27,000 square foot garden plus two large greenhouses in the Northwest part of Oregon. She raises her family’s food (three adults), as well as root crops for her milk cow, and also feeds her chickens, pigs and dogs. For years, she rarely if ever watered the outside gardens during the two to three months when there’s no rain. With advancing age and her husband’s back problems, she recently put in drip irrigation, which allowed her to cut the size of her food-producing garden in half; she grows cover crops on the remaining half and rotates it into production the next year. The caveat here is that you have to stay ahead of the weeds, as your plants won’t be able to handle any competition for water. Dryland crops also need much more space because they’re drawing water from a wider area than plants that are irrigated. Finally, you have to keep your soil loaded with humus, using compost, animal manure and cover crops.
So, assume you will have to water. Your options are a sprinkler, drip irrigation, flood irrigation or hand watering. Many people just use a sprinkler, and that’s fine. Disadvantages: some plants don’t like overhead watering and may break, fall over or get molds and other nasties. Squash, for example, is a desert plant. You can get away with a quick overhead sprinkle, but it really prefers to have only its feet wet. If you water it overhead, which I do, a few leaf stems will break off and some of the leaves may start to look a little ratty. Beans may get various diseases that are more easily spread if they are watered with a sprinkler, especially if humans mess with them while the leaves are wet. However, I will add the caveat here that most of the information about these moisture-related diseases comes from gardening tomes written by folks who garden in the humid parts of the country. I don’t think they apply out here where summer humidity measurements are often in the teens or below. I used to turn the sprinkler on and leave it all night in our former home, where we had a good deep well that could handle it. The advantage of night watering was that it slowed evaporation from those streams of water waving back and forth in the air (you can lose 50% of your water to evaporation – more in hot, windy weather). I then stayed away from the plants until the next day, when the leaves would be thoroughly dry. The system worked fine and I didn’t have any trouble with disease. I don’t know how it would have worked in a place where there was a lot of humidity.
Our house water comes from a spring, which is nice because the water is only about 65 feet down and we don’t need a massive pump. In the dry season, though, the spring fills more slowly, and with two families on the same well, we have to be careful not to drain it dry. Since that’s when I need to water the garden, I use a multi-pronged strategy on the kitchen garden. First, we’ve added a lot of organic matter to the soil. We started the kitchen garden with compost from the milk cow’s pen and the sheep’s night-time sleeping quarters. Second, I mulch it heavily with compost and grow plants fairly close together so their leaves will shade the soil (and shade out a lot of the weeds). Third, I use a daily watering technique (sometimes twice daily in hot windy weather).
In the perfect world, you want deep-rooted plants surrounded by thick mulch that you can water heavily once a week or so. I can’t do that, because the well won’t stand up to an all-night watering session that should really soak the soil. Instead, I water just enough once or twice a day to replace the moisture that evaporated or was used by plants the previous day. Most gardening experts will tell you that method is a no-no, because your plants will be shallow-rooted and if there’s a hot spell, they’ll die. I disagree. If you start with deep soil that is full of organic material and get it good and moist initially, the plants will send their roots down into the moist soil, and watering, as I’ve mentioned, just replaces the top layer of water that has been evaporated. When you think about it, that’s how nature uses rain. If it’s really hot, I will water a little longer. You have to check the soil with this method, to be sure the water is getting down into the root zone. I use a bulb trowel (skinny and long blade) to stab a deep enough hole in the soil to check for moisture without disturbing roots.
This is similar to the method used by John Jeavons, of intensive gardening fame. Jeavons says you should water a couple of hours before sunset, because that allows the plants to soak up water all night when there’s less demand from the leaves and fruits, and because it reduces evaporation. I do it twice a day because of the other demands on my time and because my kitchen garden is on a slope. If I water too heavily in one go, I just wind up with runoff. I can’t see that it makes any difference. Water until the soil stays shiny for at least 30 seconds after you move the hose to another spot. Jeavons uses this watering system because he’s trying to conserve water and prove the point that you can get major yield with minimum water input. I do it because I don’t have a choice.
The one disadvantage of this method, I admit, is that you can’t go away for a week in the middle of summer. We rarely get rain during the summer in my neck of the woods. If we do, it’s more likely to be a brief sprinkle that doesn’t even put out the lightning fires that go along with our summer thunderstorms. Drip irrigation might be a possibility and eventually we may go that route, but it’s expensive, the emitters get clogged pretty easily and it’s a royal pain to try and plan your garden to fit the drip lines, especially the small stuff like carrots and beets. Drip irrigation, in my experience, works better with row crops or in orchards. My current system works just fine. Since I rarely travel any more (which is just dandy with me) I’m around to water as necessary.
In the big garden (since dismantled), we used flood irrigation. The big garden was on a slight slope that falls away from the irrigation ditch. We turned the water into the ditch, opened the sets, and let it gently flow over the garden, guiding it as necessary to make sure the whole area got wet. Since this saturated the ground and plants need oxygen just as much as water, we then let the garden dry out until the next watering, which might be seven to 10 days later depending on the irrigating schedule and the weather.
Timing the water is critical. Many plants, especially those with big leaves such as squash, normally wilt in the middle of the day. Don’t worry if they droop a little under the noonday sun. It’s a survival mechanism that lessens the demands on a plant that evolved where water was scarce. The plants perk back up in the evening. However, if your plants are still a little wilted by the next morning, applying water then may not help them, because they can’t absorb it into their tissues. The plant’s growth will be checked and your production is likely to drop. Try watering them. If they perk up, you know they need more water on a regular basis. If they don’t, you may need to yank them out and start over.
There’s an old farmer’s saying: “Feed your soil and it will feed you.” Truer words were never spoken. Your garden makes eggplants and corn and green beans out of what it eats, just as you make muscle and bone (oh, all right, and fat) out of what you eat.
Chemical fertilizers cannot give the soil what it needs, which is a wide array of different minerals, organic matter, worms, microbes, bugs and air. Nor do they help hold moisture the way organic matter does. Unless you are lucky enough to lay your hands on some dirt that has never had anything grown on it – and those chunks of land are few and far between these days – you have to supplement it. Not to mention, that everything you harvest removes something from the soil. Unless you plan to return it in the form of your excreta, as the Chinese did for many centuries and many people still do in the backwoods, eventually your soil will be depleted. Many conventionally-farmed fields have little topsoil. Tillage farming and erosion have sent millions of cubic feet of topsoil down the Mississippi River into the ocean. In England, some estimates indicate they can get another 100 crops before the soil will no longer grow things.
In some cases, your soil starts out deficient. Many soils out here in California are deficient in selenium, for example, which affects reproduction in animals. We’re in a selenium-deficient area, so I take it as a given that my soil is short on selenium. Just as I supplement my animals with things like kelp, I supplement my soil. I use Azomite for minerals, manure from my animals (which contains the stuff I supplement them with) and grow some deep-rooted green manure crops that pull up minerals from the soil. We also spray raw milk on the garden and pastures, which feeds the soil microbes. Weeds go to the chickens, who also contribute to the manure pile. Wood ash (preferably from hardwoods like oak) is another source of minerals. There’s a constant cycling of nutrients from the soil to the animals and back again.
The big town 35 miles west of us has a compost-making system for people’s leaves and grass clippings. I prefer to make my own compost, because you never know what’s gone into the municipal version. Having had a bad experience when we first created our kitchen garden with straw that had been sprayed with herbicide, I periodically sprinkle the mulch with activated charcoal powder, just in case. I’ve never done a soil test, and I wouldn’t bother unless you’re growing in really unusual conditions and/or your plants just aren’t doing well. If you feed and take care of your soil, your plants will do fine.
Plants need air. If your soil is compacted or waterlogged, it will have less air available for the plants. Soil compaction will clobber your soil’s quality in a hurry. Don’t walk on your soil. If you garden in rows or beds, keep them narrow and walk away from the plant’s roots. Ideally, lay out your rows with a strip of grass sod between them, and walk on the sod. If you have a big garden or wide beds, lay down boards or stepping stones and walk on those.
I realize I’m a bit of a garden heretic, but I don’t believe in regular plowing, rototilling or double digging (although there is a place for these in garden renovation). The first two just create a hardpan layer below the plowed/rototilled area. In addition, soil that’s been turned over gets compacted by heavy rains, hail or snow, not to mention that it erodes more quickly. Double digging, as espoused by Jeavons, is damned hard work. As I get older, I’m just not willing to put that much effort into my gardening, especially when I see no evidence that it’s necessary. You could get away with rototilling the first time you make the garden, but after that I would just add compost, mulch and soil amendments on top of the ground, which is how nature makes soil. If you think your garden dirt needs to be “turned over,” invest in a bunch of earthworms. You’ll save your back and won’t need to buy the fancy double-digging tool. If you want to get some details on this method of gardening, check out Ruth Stout’s How to Have a Green Thumb Without an Aching Back from your library or find a used copy somewhere. Stout used a permanent mulch system and never dug, rototilled or plowed her garden after it was first created. She had an extremely productive garden and was still gardening in her nineties.