Incorrect watering is the number one reason plants fail to thrive.
People either water too much or not enough. We often get frantic calls at the nursery from customers who are seeing their recently transplanted plant wilting and dying. Our first question is how much are you watering it?
Symptoms of overwatering and under watering are similar – wilting. How can you tell the difference?
It is as easy as putting your hand into the soil and feeling the soil. Understand that a newly transplanted plant doesn’t yet have an established root system to properly support itself and so it needs your help.
Correct watering begins the day the plant goes into the ground. We recommend watering a five-gallon pot size tree with 10 – 15 gallons of water. As a rule, water with two or three times as much water as the pot size.
As a guideline, water the plant every 7 – 10 days with the same amount of water. If you notice that the plant is wilting towards the end of this period then the plant is wilting due to lack of water. If you see it still wilting after being watered and not recovering then it has too much water. Let the soil dry out completely.
Oxygen is just as important to a plant as water. Oxygen is available to the plant in the air spaces in the soil. Over-saturated soil rots the roots, the plant wilts; leaves turn yellow and fall off.
Taking notice of the type of soil you are planting in will help in your decision to water or not. If the soil is sandy it will drain quickly and soil will dry out more rapidly. If the soil is clay, it retains the water drying out slowly. That is why adding organic matter, such as compost at time of planting is so important to either of these types of soil.
Of course weather plays an important part in the equation. Use common sense; check the soil often, water slowly as watering too quickly causes runoff.
Water deeply, shallow watering dries out the top layer of the soil quickly and only encourages the roots to stay in the top layers of soil.
A deep root system allows the plant to reach available moisture in periods of drought.
Watering in the morning also reduces evaporation. Mulching trees and shrubs with 5 – 7.5 cm of fir bark mulch is also beneficial.
Jean Atkinson is a horticulturist with Richbar Golf and Garden and a regular Observer columnist.