Watering Your Vegetable Garden
From start to finish, water is the most important thing for your garden. Water is essential to plants. Most plants are composed of up to 90% water. Water is requisite for cell structure, stability and growth.
Too little water will at best wilt your plants and drastically reduce productivity. At worst it will kill them. Too much is just as bad, leading to leaf diseases or root rot, snails and slugs, a lack of oxygen or having your nutrients leach out of the soil. Irregular watering can stress your plants leading to low productivity or bolting. Therefore, if you want your garden to thrive you’re going to have to pay a good amount of attention to how and how much you water your vegetables.
When to Water the Vegetable Garden
The best time to water your vegetables is in the early morning hours. This is the time of maximum growth for your plants and it gives the soil and roots time to absorb the water fully before the heat of the sun begins its evaporative process. Watering in the heat of the day is both wasteful and potentially damaging to the plant. You lose much more water to evaporation (meaning much less water for the plant and thus more frequent and irregular watering) and cool water can shock plants. An evening watering can lead to mildews, rusts and other diseases because the water will sit over night on your plants or the roots.
How much water does the vegetable garden really need?
When you water, be sure to water thoroughly and deeply. A shallow watering or sprinkling will drive the plants roots up instead of down and a shallow root system leaves you doing more watering that you’ll want to do and will leave the plants unable to withstand windblow. Focus on the soil! Look to water your soil so that the water gets down a good foot at least. The amount of water you put on your garden is going to depend on the soil type, available sun and stage of growth…not to mention if it’s raining or not.
I’ve already discussed soil quality in this section but it is worth reiterating just how important it is to have good soil when it comes to the watering. If you grow your crops on a sandy soil the water is more likely to run right out leaving your crops high and dry and you dealing with wilted and dying plants. Growing in water-retaining clay, on the other hand, can easily leave soil water logged causing other sorts of growth issues. Get that soil healthy with a generous amount of organic matter and mulch it thickly to conserve water in the vegetable garden.
Some vegetables will need extra water at certain times. Beans, peas, potatoes and corn need more water when they flower (but less prior to that). Squashes and tomatos need extra water while they are growing their fruits. Salads and root vegetables like carrots and beats need a steady supply of water throughout their growth cycle. Certain crops tend to be on the thirsty side all the time. Beans and peas, beets, carrots, cucumbers and squashes should be grouped in the same general area when you plant to ease your watering situation.
The best way to avoid overwatering is by sticking your finger in the ground. Ideally, it will feel damp but if it feels soggy, don’t water. Give the garden time to dry out a little bit. If your plants are starting to suffer consider taking a pitchfork and punching holes in the soil to let the water drain away. I’ve placed a thin layer of one inch gravel in the bottom of some of my raised beds to allow water to drain off in case I get careless or there is some tremendous rainstorm. This seems to work rather well. If you’re crops are wilting and appear dried out give them water right away (never mind the time of day) and, if possible, get them in the shade.
Here’s great information on critical watering periods for vegetables:
Critical Periods for Vegetables. While most vegetables require adequate moisture from the time they are seeded or transplanted into the garden, there are critical times when they definitely require water. The crops and those critical periods are given below:
Vegetable Critical period for water needs
Bean, lima: Pollination and pod development
Bean, snap: Pod enlargement
Broccoli: Head development
Cabbage Head: development
Carrot Root: enlargement
Cauliflower: Head development
Corn, sweet: Silking, tasseling, and ear development
Cucumber: Flowering and fruit development
Eggplant: Uniform supply from flowering through harvest
Melon: Fruit set and early development
Onion, dry: Bulb enlargement
Pea: Flowering and seed enlargement
Pepper: Uniform supply from flowering through harvest
Potato: Tuber set and tuber enlargement
Radish: Root enlargement
Squash: summer Bud development and flowering
Tomato: Uniform supply from flowering through harvest
Turnip: Root enlargement
Jim O’Donnell gardens in the mountains of northern New Mexico. A certified permaculture designer and ecological restoration specialist, Jim’s first book Notes for the Aurora Society was published in 2009.