WHEN TO WATER VEGETABLES
Ross Penhallegon, is a horticulturalist with Oregon State University, outlines how/when to water vegetables:
It is recommended that vegetables be watered during the early morning hours. It is cooler in morning hours, and this allows for more of the water to be absorbed into the soil, rather than some being evaporated. There is also less wind in the early morning hours, and so the hose/soaker hose pattern will not impacted by the wind.
The hours between 5am and 10am are ideal for automatic watering systems.
Watering during the late afternoon should be avoided because having the leaves stay wet into the night increases the chances of the vegetable plants becoming diseased. Increasing the probability of plants becoming sick if their leaves continue to be wet into the night, is also applicable to turf, and flowers.
If the plants are drooping during the late afternoon, it is okay to water them. However, some plants may become burned if the water remains on their leaves in the sunlight.
If the plant is a dull green, wilting, or growing slower than it should be, it is probably lacking water. If the surface of the soil is dry, that does not necessarily mean that the plant is in need of water. However, if the top 1-2 inches of soil a dry, a watering is probably needed.
There is also a time for particular vegetables, in which they need more water:
Beans: when flowering or pod is developing
Broccoli, cabbage, and other cole crops: when the head is forming and becoming bigger
Carrots/taproot vegetables: staring from germination up until harvest time
Corn: when transitions from tessel to silk and when ears fill
Cucumbers: when flowering, and the roots are developing
Eggplants: from the time of blossom and the enlargement of the fruit
Lettuce/leafy vegetables: Starting form germination until harvest time
Onions: When bulb is forming
Peas: When flowering, and the pods fill
Peppers: Starting from blossom and through fruit enlargement
Potatoes: From blossom until they hare harvested
Tomatoes: From the time they blossom and through the time when the fruit is enlarging
Woods, T.(2014, June 20). Timing Can be Important When Watering Vegetables. Retrieved from: http://extension.oregonstate.edu/gardening