Whether newly installed or already established, all plants need regular amounts of water to thrive and produce lush, healthy growth and in the case of some plants, luscious fruits and luxe flowers. While it can take some trial and error to find the watering regimen that’s right for your plants, soil, and climate, here are some general guidelines to get you started.
If you have questions about watering (especially particular plants) please do leave a comment below. We will do our best to get you on the right track!
No. 1: Compost, mulch (and mulch again)
We’ll say it again–soil that’s friable and drains well is your best friend when it comes to watering. Water can more easily reach the roots and hold moisture better. Before we dive into best practices for watering, remember to always be improving your soil with twice a year applications of organic compost and routinely layering on several inches of mulch to both hold moisture and feed soil organisms. Okay, lecture over. Let’s get to watering.
No. 2: An Ounce of Prevention
Keeping soil evenly moist and avoiding letting it dry out too much between waterings is the best way to ensure that your plants do not become stressed and that the fine, hair-like projections on the ends of the roots do not become damaged. Not sure if you need to water? Simple solution is at your finger tips–just probe down a few inches to see if the soil is dry. If so, it’s time to water. If not, wait a day.
No. 3: Hit the Ground
Avoid overhead watering and wetting leaves which can promote fungal diseases. Instead, water at the soil level and keep applying until the plant’s entire root ball is completely soaked.
No. 4: How Much is Enough
Be observant. Your plants will pretty much tell you what they need.
Give trees and shrubs—especially newly-planted ones—direct watering every 7 to 10 days; don’t rely on sprinklers or irrigation systems in the heat of summer to deliver the necessary moisture as roots will be both wide and very deep. For perennials and annuals, you can water by hand, or with an automatic irrigation system with moisture sensor, or a soaker hose.
If watering with a hose or watering can, start slowly and allow the top inches of soil to absorb water then gradually add more water for a thorough soak. This can mean watering two or more times in a session.
If employing an irrigation system, either depend on the moisture sensor or use the can test to help figure out how long you’ll need to run the system to get the adequate amount of water. (The “can test” is simply placing an empty can in the watering zone, turning on the irrigation system and seeing how long it takes to get one inch of water into the vessel. That will give you great info on how long to run your system.)
If using a soaker hose, use a moisture probe or just your finger to see how long it takes for the system to get soil thoroughly moist 1 -2 inches below the surface and then set timer accordingly.
How far out from the base of the plant should you thoroughly water? The roots are probably as wide as the plant and may be a foot or two deep.
One great way to get this right, especially with newly planted specimens, is to build a soil berm from compost (apply 3 inches of compost around the plant and then pull it back from the base of the plant to the outer edge of the plant’s canopy to form a circular wall) and fill that space with water twice or even three times until the water is absorbed.
No. 5: How Often?
If it doesn’t rain, plan on one to two deep watering sessions per week which is usually sufficient for most plants. This equals about an inch of water per week. For fast draining soils, a ½ inch of water over two sessions is best, while with heavier clay soils plan on one deep soak watering session per week.
Remember this golden rule: its better to water less often but with plenty of water than to give your plants just a little water more often! (Think about it–less work for you, too!)
No. 6: Remember, your plant has four sides
Blasting one spot at the base of your plant can lead to one-sided root growth and plant stress. The best way to ensure that you are getting water to all of the roots on all sides of the plants is to put hose on a trickle and lay it near the base of the plant. Let it run for 30 minutes or more. Then, move the hose to the other side of the plant and water as above. The next time you water, lay the trickling hose on the third and fourth sides of the plant that had not been watered previously. This way, over the course of a week, all sides are getting the water they need. (Plus, you can be enjoying morning coffee or an evening glass of wine while you wait to move the hose!)
No. 7: Water late in the evening or early in the morning
The best time to water is in the early evening (so any water on leaves can dry before evening chill sets in) or in morning between the hours of 6-10 a.m. The cooler weather reduces evaporation and allows the plant to drink up all that it needs to survive the heat of the day ahead.
This also means that you will need to resist the urge to grab the hose when it’s 3 pm and your plants are sad and wilted in the heat of the day. They will perk up when the cooler evening air sets in.
No. 8: Too much is, well, too much!
Plants need oxygen as much as they need water, and roots growing in waterlogged soil may die because they cannot absorb the oxygen needed to function normally. It’s always best to water deeply and less frequently. If you see your neighbor out there everyday with the hose, do them (and their plants) a solid and remind them of this bit of plant science! How do you know if you’re over watering? See box below.
What About Containers?
- Be sure your pot has adequate drainage holes (if not, either drill them or use the pot as a decorative vessel into which you place a pot with a drainage hole.)
- Water only when the top of the soil is dry. Before you grab the hose, check the surface of the soil in the pot either by probing with your finger. If the soil is dry to the touch one inch down (or looks dry), water your plants.
- Water until water comes out of the drainage holes. This indicates that you have watered thoroughly and the root ball is evenly moist. Too little water inhibits growth of deep roots which plants need to do their best.
- Don’t allow your pot to sit in standing water as this can cause root rot, a condition that plants can rarely survive.
- As plants get larger during the growing season and as the high heat of summer comes on, check your containers at least twice a day and water as needed.
Signs You Might Be Overwatering!
- Stunted slow growth with yellowing or browning leaves.
- Leaf scorch or leaf burn.
- Water soaked spots and blisters (Oedema) on stems and leaves.
- Root rot (a fungal disease that will cause the roots to turn grey, brown or slimy and will eventually cause the plant to wilt) that eventually leads to the crown of the plant dying.
If you observe any of these indicators, immediately reassess your watering protocol and seek help from the professionals at a local garden center. Do not wait!
Best Tools for the Task
- Drip irrigation system with moisture sensor and timer–plenty on the market from those with smart technology to old school types that require a bit more input from you.
- Soaker hose with timer–ideal for all kinds of plants, but vegetables such as tomatoes in particular.
- Watering can with fine rose (nozzle)–while you will NOT be watering foliage, this is a good way to slowly get moisture directly to the base of a plant.
- Moisture meter–very inexpensive gadget that’s inserted into soil (great for pots) for an instant reading about moisture levels and recommendations for watering.
- Watering wand–attaches to a garden hose and dispenses a gentle spray that’s very welcome to new growth; great for gently hosing away pests like aphids.