Watering Your Garden
Usually you think of watering a garden as simple a task as going over it with a hose. There are some do's and don'ts, as well as healthier, more efficient, and water-conserving methods to irrigating your crops.
Most vegetables do best with a moderate amount of water. You want the soil to be moist, but not soaked, and should be allowed to dry out some between waterings. It is easy to save a dry, wilted plant; but once you overwater and drown it, it is often a lost cause. Overwatering usually causes yellow leaves and rot. Underwatered plants will just be a bit wilted, not not grow quickly.
In many areas, normal rainfall will keep a garden sufficiently watered. I can remember in Houston, TX, we very rarely needed to hand-water our garden, and never watered the flowerbeds. Here in Central Texas it is quite a bit drier, our last several years we suffered a severe drought, even causing many cattle ponds to dry up and farmers lost livestock and crops.
If you do need to water your garden, there are several methods.
You do not want to destroy your soil with hard water currents. If you have small beds or practice square-foot or container gardening, you will want to use a nozzle on your hose that diffuses the water like a gentle rain. Those variable-spray trigger nozzles are great, but I often use an antique aluminum one with just holes in it.
For larger beds, such as what I currently have, and in my climate, hand-watering is not an option, unless I set the hose in a bed while I am working on other chores and move it as needed. I typically use a hose-end sprinkler for watering. This mimicks natural rain, and washes off any Sevin or diatomaceous earth I have used, and gives me time to work on other things. I have a small round spining sprinkler I use occasionally, or one of the ocillating bar types. I prefer the bar sprinkler, since it waters more of a square area than round, and with the model I have, you can control the width of the spray as well as the direction. This allows me to water a very large area such as the garden, or a smaller area like the greenhouse. I can leave the sprinkler running for an hour or more to throughly saturate the ground.
Sprinklers like this are good, as they cover a wide area, and can be adjusted to avoid over-spray. I've found this enclosed-motor type is also more durable and reliable than the typles with the narrow metal tube and external motor, which can dislocate and slip...a big problem when you have kids that play with it.
If you use row gardening, you can set the hose to fill the "ditches" between rows. Place your hose at the higher elevation, allowing your water to flow downhill. If you are on very flat land, you may have to move the hose to the other side to water both ends of the rows equally. Use some stones, old bricks, or tiles to keep the flow of water from washing away the soil in that spot.
Soaker hoses can also be used. You can make your own soaker hose by just making holes in an old garden hose and blocking the end.
Be aware that most municipal water sources add chemicals to the water, such as chlorine and flouride, which can build up in the soil and plants, as well as other chemicals. Municipal water is often very "hard", causing mineral deposits (that white, funky build-up). This can build up on leaves if you do not recieve much natural rain. Well water is the safest water source for hose-watering.
Most of us know what grey water is. If you do not, it referrs to all waste-water from your home that is not sewage. In other words, the water that goes down your sink, tub, and washing machine drains. Unless all your home's greywater is routed into the city sewage, you can harvest this for watering your gardens.
Most drain-lines are made of a 2- to 3-inch diameter black plastic pvc pipe. If you can find your existing buried line, or it is already exposed, you can buy however much pipe you need at a hardware or farm and ranch supply store. It is flexible, and sold by the foot, or by the roll. connectors and size-converters are also available, usually grey. Pipes can be run to your garden area, or into a collection container for more controlled usage. For direct application, you can let the water drain directly into an open ditch to seep or run into your garden soil, or perforate the last section of pipe and bury it. I recommend surface watering for clay soils, but a buried pipe is fine for sand. Make your holes at least 1 inch in diameter and 1 foot apart at the end of your pipe...becoming smaller and further apart closer to the source. You will have more water pressure on those first holes, and if they are too large, it will all drain out before reaching the end of the pipe. You could do a single pipe section along the length or down the middle of your garden plot, or make sectioned joints to distribute the water over a wider area. Put the holes on the sides of the pipe (one side or both) to direct the water out into the soil instead of straight down. Avoid planting directly on top of the buried pipe...you can cover it with something to keep anything from growing over it and reduce evaporation.
Line your trench with rocks, gravel, bricks, and broken cement to avoid clogging the holes and improve drainage. Telescoping your black drain pipe inside of a larger 4- 6-inch plastic perforated pipe will also help avoid clogs. A buried pipe may have to be dug up and cleared periodically, this can be done when tilling.
I have my bathroom greywater (tub and sink) routed to the vegetable garden using the 2-inch black pvc pipe. The entire pipe is buried, and runs along the front edge of the garden, which is the highest point of elevation. I noticed the first year I was having a lot of extra weeds and grass growing on the non-garden side, even though I had the holes directed towards the garden and the pipe was unburied in a trench. I fixed this problem by digging a 1-foot deep trench, and installing a plastic barrier. I had some siding material from an old above-ground pool that worked perfectly for this. We had been using the stiff fiber-reinforced plastic for other things like skirting on parts of the house, and already had a 1-foot wide strip that was just long enough. I also added 2-foot lengths on either end to help direct water seepage.
I would not recommend using kitchen sink greywater, because of the amount of food debris. You will end up with clogged pipes and a sticky, stinky, slimy mess. Avoid using harsh chemicals, as well. We typically use all-natural soaps, and a dye- and fragrance-free natural laundry detergent.
The best source of water is rainwater. It contains no added chemicals (well, its not SUPPOSED to anyway, there is quite a bit of debate over airborne chemicals now), no extra minerals, and is what plants are used to getting. Even houseplants will be much happier and their potting soil healthier if watered with rain.
Conjoined barrels will increase your water-storage capacity. Each consecutive barrel will have to be slightly lower elevation than the previous to aid flow.
Roof runoff is the best way to collect rainwater. It's pouring off your roof anyway, and most houses already have gutters. If not, you will have to make or install some. 50-gallon barrels are available from many sources...try to get plastic barrels that have not been used for anything poisonous. Chlorine and food-stuff barrels are fine. Steel oil drums are completely out of the question. You can also buy larger storage containers from your hardware or ranch supply store. They are usually black or semi-transparent white... an employee can help you choose what you need. These can be connected to your gutters to collect rain as it falls, and saved for when it is needed. You will need to install a spigot if there is not already one on the container to connect a garden hose.
To make your houseplants happy, set them outside when it rains. They will get all the water they need, the dust will be rinsed off their leaves, and soil will be cleansed. Plants breathe through their leaves, so having a layer of dust complicates things, not to mention it is unsightly. Without flow of natural clean water, and the benefit of earthworm and insect activity, potting soil becomes compacted, stale, and clogged with chemical residues and hard water deposits.
While plants need plenty of water, too much can choke them. Poorly-drained soils can become waterlogged and stagnant, suffocating roots. Plenty of organic material, and larger soil particles like sand will improve drainage and porosity, but raised-bed and container gardening sometimes poses a problem. Make sure your raised beds can drain if you have very dense soil underneath. Use a porous or absorbant material like rock, brick, or wood. Make sure there are spaces every so often for excess water to drain out. If you have used an impervious material like dense of close-fitting bricks, lumber, metal, or plastic, make sure you install some drains. If you are container gardening, do not set the containers flat on the ground. Raise them at least an inch or two...bricks work well. If raising them is not possible, consider drilling holes into the sides of your container at the bottom, at least 1/2 inch in diameter.
Often, in sandy soils especially, water-seepage is a problem. Your precious water wicks away into surrounding soils. You can install barriers around your garden area by burying sections of plastic, metal, brick, rock, or wood around the perimiter. Adding organic material to your soil will help hold water where needed, as well, acting like a sponge.
Avoid evaporation by mulching around plants. Some seeds can be scattered directly on top of mulch and watered in, others can be poked in or a hole made in the mulch. Otherwise, wait until after your plants have sprouted or seedling planted to mulch your garden.
Good organic mulches include wood bark, shredded or chipped wood, hay, grass clippings, and newspaper. Inorganic mulches are better for wintertime gardening and can include black plastic and aluminum foil. The benefit of organic mulches is that water can permeate directly through all of the mulch, and it can be turned back into the soil. Plastic and foil can provide extra heat in wintertime, and foil will reflect light. Often we have an over-abundance of sun in summer, and not enough in winter. I have heard tomatoes benefit from a red plastic mulch, but I have not tested this for myself. Flat stones, tiles, and bricks can also prevent evaporation, as well as totally omit weeds from the area and make a fine stepping area without compacting soil.
My garden utilizes plastic and brick walkways which hold in soil moisture, periodic cement step-stones, and hay and grass mulch. The amount of compost and manure we add greatly improves the sand's ability to hold water. Rabbit manure can be used fresh and can hold quite a bit of water in the soil.