General Rule of thumb(s)
- For every inch of inch of caliper, its 10 gallons of water per week. This is the general guideline for wire basket or burlap trees
- In potted trees, the size of the pot is the number of gallons the tree should receive each week. For example, a tree in a 5-gallon pot should get 5 gallons of water per week.
- Whatever the size of the pot is, half the number and that will be the amount of water needed. For example, a 2-gallon pot will need 1 gallon of water per week.
- Whatever the size of the pot, is equal to the number of gallons of water the shrub should receive each week. For example, a 5-gallon pot should receive 5 gallons of water per week.
Watering infrequently, but deeply is the best way to promote deep root growth. Shallow and infrequent watering encourages roots to grow near to the surface, which makes them much more susceptible to drought in the long run. By watering deeply and infrequently, you force roots to grow downward in search of water, which allows them to draw water from deeper sources in times of severe drought. This means that you will water much less in the future, with proper care and due diligence in the first two years of establishment. Typically a once a week watering that you deliver all the required water slowly in one event is the ideal way to water plants.
Overwatering versus underwatering
The signs of overwatering and underwatering are rather similar, as in both cases the plants will appear to wilt. However, it is already better to air on the side of dry. It is much easier to add more water, but it is a lot harder to remove water once it has been added. Overwatering will promote root rot, and the plant will slowly decline. Underwatering will cause the plants leaves to dry out, and once it is past the permanent wilting point it will not be able to bounce back. Most plants are resilient and will come back from being too dry and wilting, so as mentioned previously it is much better to be on the dry side of things, as you can always add more water.
If you find manually watering a challenge there are supplies that can help ensure your plants are getting the proper amount of water they need. There are various water bags available for your needs and for the type of plant.