The Region of Durham and the Town of Ajax currently supplies our water as a gift; the Garden Committee is conscientious not to abuse this privilege, as the possibility to have to pay for water would dramatically increase our plot fees.
It takes our volunteers up to three hours to fill our water, and barrels are filled up to three times each week: Tuesdays, Fridays & Sundays.
Watering your vegetable plot
Less is often more when watering your veggies; a common mistake many gardeners make is watering too much!
Historically gardeners were advised to make sure that their vegetables received up to three centimeters per week. This originates from the old rule of thumb understanding that it takes approximately 3cm of precipitation at one time to deliver enough moisture to reach the deep root zone. In fact, this is not the case.
There are methods and practices that will have you using less water, while still achieving better results with your plants.
Cultivate your vegetables
Frequent cultivation prevents the wicking-up process that draws water from the lower root level to the surface of the soil. By aerating the upper layer of soil, cultivation also greatly improves the capture and retention of rainfall. Plus, it disrupt the germination and growth of weeds that would compete with crops for water.
Cultivate your garden early and often. Hand tools like a hoe will work fine in your plot, fluffing up only the first 3-5 cm between rows, being careful not to disturb crop roots.
Timing is important: many gardeners stop cultivating their gardens mid-summer once crops are established enough to out-compete weeds. But with mid-summer being the hottest time of the year, soil and plants are most vulnerable to moisture losses through evaporation and transpiration, the perfect opportunity for weeds to once again rear their ugly heads.
Traditionally, farmers & gardeners cultivate their crops three days after a good soaking, to prepare their soil for the next rainfall. After a rainfall, stay off (don't step on) freshly cultivated soil for about three days, in order to prevent soil compaction and allow the water to percolate down to the lower root zone. You want plants to root deeply so that they don't become dependent on surface watering.
Lose your guilt about plot wilt
Temporary wilting during the heat of mid-day does not mean that it's time to water. Some plants go through an obvious mid-day slump, an indication of that plant's natural ability to adapt to its environment. Visit your plot again in the evening, and see if those wilted plants have regained some turgidity. If they've come back, then you don't need to water.
You don't need to baby your crops; plants are incredibly adaptable, and have the ability to draw water from deep in the soil. If you're concerned about your soil's moisture content, you can periodically use a trowel to to dig down several centimeters to where the roots are most active; if the soil there is still moist, there would be no benefit to watering.
How and when to water
First things first: when you water, you must remember to water the soil and not the plant, as water droplets on the plant will attract & magnify the sun's rays, leading to burn damage.
What you want in a healthy plant is deep root penetration, and the only way to get that is to make sure that there is water down deep for the roots to seek out. The best time to water is in the morning, while the soil surface is cool; try to avoid watering later in the day, as water will ultimately evaporate on warm soil, all benefit to the plant will be lost.
Start at the very beginning: when transplanting seedlings into the garden, completely saturate the plant hole before placing your freshly watered seedling into it.
Sometimes the best time to water is immediately following a rainfall, especially when rain showers are light or short. The reason for this is to ensure that there is enough water to penetrate right down to the root zone, when a rainfall may not be sufficient enough on its own. If you wait a couple of days, then you would only be adding surface water, which evaporates quickly. With only frequent, light watering or rainfalls, you will never build up the reserve of water in the soil that plant roots need for optimal growth.
If you're not sure how much rainfall is reaching your garden, you can install a simple rain gauge in your plot. You can measure how much rain water your garden is getting, and time how long it takes a good, steady rain to drop enough water to reach your roots. If you don't have a rain gauge, you can use a clean, empty tuna or vegetable can and a ruler in its place.
So, cultivate and water in the rain when required, and learn from nature; spend more time observing your plants and what they're telling you, and less time filling up the watering can.