Place gallon jugs or jars of water (size dependent on how long you expect to be gone) alongside your plant with a piece of twine or yarn in the water, and the other end around the soil of the plant. The water will wick from the jug to the plant and keep it's soil moist while you are gone.
Fill a jar, cup or bottle full of water and place next to your pot, positioning it out of direct sunlight, and elevated so that the mouth of the container is higher than the base of the plant. The longer you are going away for, the larger you will want this container to be.
Place a damp towel in the bottom of a large, clear plastic bag. Make sure the plastic bag is big enough to fit over your potted plant. The bag will trap moisture in the bag so it drips back into your plants, watering them.
Wetting leaves.
Plants get their moisture through their roots, not their leaves. Direct watering to the soil surface and avoid wetting leaves because water helps spread some plant diseases. Use a watering wand to reach ground level or a soaker hose or trickle irrigation system to wet the soil rather than the leaves.
If your plants are in the ground (versus a pot), the general rule is that plants need one inch of water per week. However, this does NOT mean watering one time per week. That doesn't usually do the job. Plants do best when watered deeply about three times a week, factoring in the rain.
The best time to water your garden in summer is from 6 am to 10 am—before the heat of the day sets in, giving your plants plenty of time to drink up and any moisture on the leaves to dry off before nightfall. What is this? If watering in the morning isn't possible, the next best time is from 4 pm to 7 pm.
Most outdoor plants can go without water for about a week. Container plants are the thirstiest. Most need to be watered daily. If you're planning to be away, adding mulch around flower and vegetable beds helps keep moisture in longer — even if it doesn't rain during your absence.
If you have just a few outdoor containers, you may want to opt for Plant Nanny Wine Bottle Stakes. Simply screw a wine bottle filled with water to the stake, then insert the stake into your potted plant. The water will release slowly and steadily while you're away.
Types of Plants That Like Mist
Tropical houseplants and plants that love high-humidity—such as the Chinese Evergreen, Boston Fern, and Majesty Palm—will benefit most from misting, says Plunkett. (Zebra plants, orchids, arrowhead plants, and begonias are just a few others that love mist.)
Attach Soaker Hoses to Rain Barrels
And they can be adapted to help keep plants hydrated while you are vacationing. If you have a rain barrel, attach a long soaker hose to it and run it through your garden. The water captured by the barrel will leech out slowly and saturate the ground.
The best water for your plants is rainwater. It's clean and chemical-free. Rainwater contains the highest levels of oxygen, which is beneficial to plants. High oxygen content in water leads to larger root mass, encouraging faster intake of nutrients and plant growth.
To help your plants from wilting while you're away from lack of water, you can move them a little bit further away from their source of natural light. Place them in the middle of the room so that the heat and light from the windows does not dry them out as fast as usual.
During really hot weather, water your vegetables at least two to three times a week. Watering the garden deeply is critical. The water must go down, down, down to encourage deep roots and get away from the hot soil surface.
If the soil feels dry, it's time to water. In the spring and fall and in cooler climates, it might be sufficient to water container plants every two to three days. In the summer and in warm climates, container plants usually require daily watering, unless they are succulents or other drought-tolerant xeriscape plants.
Overwatering is one of the more common causes of plant problem. Heavy and poorly drained soils are susceptible to becoming waterlogged. Roots growing in waterlogged soil may die because they cannot absorb the oxygen needed to function normally. The longer the air is cut off, the greater the root damage.
When the air and soil temperatures consistently fall below 40 F, it's time to stop watering. The ground can't absorb water once the top few inches freeze. Continue to water your plants up until this point so they're as well-hydrated as possible going into winter.
The best time to water plants is in the morning or evening.
If you water in the afternoon, especially during summer, the heat and sun are at their peak and the plant's water will evaporate instead of absorbing into the soil and roots.
Plants can go to a maximum of a week without water, however, some plants can go for even longer periods of time, such as for two weeks or even a month. It would depend on the type of plant and its drought tolerance level.
During extremely hot weather (daytime temperatures above 90F and nighttime temperatures above 70F), try to water daily or every other day. In a 10x10-foot garden, this would mean giving your plants 8 to 9 gallons of water each day.
In hot weather you need to water in the mornings when it is cooler. This will allow more water to reach the root system before it evaporates in the heat. There may be times when you cannot schedule watering in the morning. In this case, water the plants in the late evening before bed.
Water gardens early in the day when it's cooler and less windy. Watering in the heat of the day shouldn't hurt the plants -- it actually cools them off -- but it's a far less efficient use of water as much of it will evaporate before reaching the roots.