Proper watering is one of the most important factors for the establishment of all new plants. Every outdoor plant, whether hardy or tropical, grown in a container or in the ground, has different watering needs. Light level, sun exposure, soil type, air temperature, wind, rain, and how recently it was planted all affect the water needs of your plants, so here are some tips from our horticulture experts. 

For Trees and Shrubs planted in the ground … 

In general, we recommend watering newly planted evergreen and deciduous trees and shrubs 2 to 3 times per week spring through fall. Proper watering technique for trees and shrubs can be achieved with a slow trickle from a hose directed at the soil/rooting zone for about 30 minutes OR a minimum of four to five 15 to 20 second passes with a water breaker directed around the soil/rooting zone. Watering the foliage/leaves is not helpful.

Once the final leaves drop from a deciduous tree or shrub you should water one more time before taking a break until the following spring. Evergreens should continue to be watered in the winter, up to 2 times weekly, as temperatures continue in the 50s and 60s. When temperatures drop into the 40s and below they may need to be watered weekly if the weather is sunny for more than 2 consecutive days. The following spring, newer trees and shrubs should be watered when conditions are dry (no rain within 10-14 days).  This routine may need to be repeated for the first 3 years, depending on the species and weather conditions. 

For Perennials, Annuals, Tropicals, Herbs, Vegetables, etc. planted in the ground … 

In general, we recommend watering newly planted perennials, annuals, tropicals, herbs, and vegetables planted in the ground or large raised beds more frequently, but for a shorter time, than trees and shrubs. These types of plants typically come in smaller pot sizes (aka they have smaller root systems) that can dry out faster than shrubs and trees. When planting in spring, summer, or early fall, you will want to check your plants daily for the first 3-4 weeks and water as frequently as needed (sometimes daily) until they are rooted out. Proper watering technique for these types of plants can be achieved with a minimum of two to four 5 to 10 second passes with a water breaker directed around the soil/rooting zone. Watering the foliage/leaves is not helpful.

After 3-4 weeks they should be rooting out and establishing themselves, thus decreasing the frequency you will need to water. As winter approaches in mid to late fall and temperatures (hopefully) are decreasing your watering frequency will also decrease. After a frost or freeze you should not need to water perennials again until the following spring. Remember, annuals, tropicals and most vegetables and herbs are not winter hardy in our area, so they will not come back the following spring. Some perennial plants may need occasional watering the following spring if drought conditions persist. 

For plants in pots … 

In general, plants in pots have a much faster water loss rate as compared to plants in the ground, so we would recommend checking outdoor pots daily, especially March through November. Frequency and quantity of water is dependent on sun exposure, wind movement, air temperature, humidity, location of pot, type of potting soil, type and size of plant, and size of the pot; therefore, we cannot give a one size fits all answer. For personalized watering guidance for pots, please email or text our team. For bonsai watering tips, check out our bonsai guide. 

What about rainfall?

 While it would be nice to be able to rely solely on rainfall for watering, in our climate that is just not possible. Natural rainfall can only be relied on to sufficiently water your plants if more than one inch falls per episode (without heavy wind) and the plant is in a location/position to receive it.  

To determine whether a rain event was effective in watering your plants you will need to know three things: what type of soil you have, whether or not your soil was wet or dry prior to the rain event, and the amount of moisture that fell.

Soil Types: Native/Ground soil types range from sandy to loamy to clay. Plants need oxygen in the soil to take up water. Sandy soils take water quickly but hold water for the least amount of time, and are the most oxygenated soil type. Clay soils take water slowly and often lose rain water due to runoff. Clay soils are also dense and have less oxygen so some of the water that they are able hold is not necessarily extractable by plants. Loamy soils fall in the middle.

Soil Physics: Soil must be moist before the water will move. The best time to water is actually during a rain event such as a mist or drizzle. This type of rainfall will typically only wet the soil to a ½ inch, so watering during this time will help you reach a greater depth. 

Amount of Rain: Heavy, fast rain events may be effective in wetting sandy soils because they take water quickly, but they will not be as effective in loamy or clay soils. In a sandy soil, one inch of water that does not run off or evaporate will wet the soil 12 inches deep, but it can take up to 2.5 inches of rainfall to wet a clay soil to the same depth. When in doubt, dig down a little in the soil to see how wet it is following a rain. Then you will know if it's time to water.

Final Tips

Mulching your plantings, even the surface of container plantings, will help conserve soil moisture, moderate soil temperature, and discourage weeds. It also provides an essential mower/string trimmer barrier. For ground plantings, no more than 2–3 inches of mulch is necessary, avoiding the plant’s trunk. 

Quality tools are also important when it comes to watering. If you have a lot of plants and/or pots, using a hose with a wand and a water breaker is the easiest and most effective method. Water breakers provide a thorough, soft shower of water that mimics rainfall.  Using this equipment with your hose will allow you to easily reach the roots of the plant, alleviate physical strain, and avoid watering the foliage, which can increase the risk of powdery mildew and other fungal diseases.

Watering cans are also great, but are most useful when you have a smaller amount of plants to water or you cannot reach the plant with a hose. Irrigation systems and sprinklers are perfect for watering lawns, but should not be solely relied upon to provide adequate water for plants. If you are using a revolver nozzle at the end of your hose, make sure it is set to the soft shower setting, leaving all other settings for other outdoor activities like cleaning, bucket filling, etc. The best tool for watering outdoors is going to be a water wand with a water breaker nozzle (soft shower). 

Need some new watering tools? A rain gauge? Mulch? Or even just some advice? Stop by and our team can help you. You can also give us a call, send us a text, or email us.