Water Requirements

Water requirements as presented are after plants are established, which usually means they have lived through one or two summers. Newly planted plants, even if they are naturally low water users, require regular irrigations, perhaps multiple times each week, particularly during summer. Plants in containers also require more frequent irrigations. All suggested watering requirements are guidelines, not hard and fast rules. Weather, soil type, sun exposure, plant type and general climate (desert, mountain and coastal regions all differ) are among the many variables to consider. Best bet? Become a regular observer of the plants in your landscape. Watch for change in leaf color, curling leaves or wilting. Try to water before plants show this much distress. Dig down into the soil (being careful not to damage plant roots) and check for soil moisture to be sure. Keep soil moist, but not saturated. Overwatering can damage or kill plants as well.

Very Low Water: After plants are fully established, deep soak every 21 to 30 days or so, less frequently in winter. Some cacti and other succulents accept even fewer irrigations. Your observation of plant health is critical.

Low Water: Water every 12-21 days during summer after plants are established. As mentioned below, observe your plants often and adjust amount and frequency as needed.

Moderate Water: Water every 7-12 days during summer after plants are established.

High Water: Water once or twice a week during summer.

Exposure to the Sun

Reflected Sun: This is the toughest exposure, one that usually faces south or west. In this location sunshine bounces off walls or structures, magnifying heat and sunshine, which can burn sensitive plants.

Full Sun: These are typically west- or south-facing exposures, which receives at least eight hours but often more of sun each day.

Partial Sun: An eastern exposure or a location shaded for some part of the day by a building or taller plants.

Cold Hardiness

This number represents the coldest temperature in degrees Fahrenheit each plant is known to survive. There are many variables when determining cold hardiness for plants, so use this rating only as a guide. The majority of plants included in the database are adapted to the average low temperatures of your region, but averages do not tell the whole story. Some years the low temperatures will be lower and some years higher. Use caution when purchasing plants that may not survive a given year’s low temperatures, and be ready to protect borderline plants when temperatures threaten to drop.

Canopy Coverage

Canopy Coverage is the amount of shaded area in square feet that a plant will cover when it is fully grown. This information is important if you participate in a lawn/turf replacement program. Refer to each plant’s description to find its Canopy Coverage number. Because Annuals are temporary plants, they are not eligible as replacement plants as part of a lawn/turf replacement program.