Native to the American West, ponderosa pine (Pinus ponderosa, U.S. Department of Agriculture hardiness zones 3-7) makes a pyramidal-shaped evergreen when young. Under landscaping requirements, it can finally develop to 60-100 feet tall and 25-30 feet wide. Ponderosa pine grows best in moist soil but can adapt to a variety of soil types. It’s drought-tolerant but water requirements vary based on the age of the soil the plant, exposure, and climate conditions.
Seedlings
Seedling ponderosa pines need deep watering during the first 3 decades of their lives, particularly during summertime. The plants send deep tap roots — around 20 to 30 inches long — that help anchor them and enable them to use deeper soil moisture out. They also develop a wide root system. Supplement natural precipitation from May through the fall months to keep the soil moist but not wet. This permits root development.
Established Trees
12 to 24 inches can grow a year once there is a good root system in place. Spaced moisture throughout the year helps to achieve growth. To preserve soil moisture and decrease watering, mulch the ponderosa pine for 2 feet out past the drip line of the tree. Mulching also prevents competition. Ponderosa pines will require water during summer dry periods and during dry winter conditions, windy, particularly when snow cover is lost and days are warmer.
Soil Types
Ponderosa pine can grow in the alkaline and acid soils — pH 4.9 to pH 9.1 — and onto a wide variety of soil textures and types. On the other hand, the amount depends on the roots grow. Ponderosa pine develops origins in coarse- or lands, rather than finer-textured clay lands. In clay soils, roots rarely go down over 3 feet, while in open lands, roots stretch for 6 feet or more. Ponderosa pines are prone to waterlogging problems because of poor drainage. Amend the soil before planting if necessary to supply drainage so that it can be watered as needed.
Exposure
Trees that are planted with exposures or who need to withstand windy conditions, like a row of trees will require more water during dry spells. Neighbors that are close are not tolerated by ponderosa pines in plantings because of the shade plants generate and because of the competition for soil moisture. Space picked a place and trees at least 20 feet apart.
Container Plants
Young ponderosa pines can be grown as container plants for a little while and then place into the landscape later. While in trees, containers might need to be watered several times a week or more throughout the summer, depending upon climate and container dimensions. Use an open, well-drained potting mix, such as 50 per cent vermiculite or perlite and 50 percent peat, and permit the upper 2 inches of soil to dry between waterings. Water trees as needed, even in winter. Ponderosa pine is increased as a subject, with particular consideration given in choice of potting mix and watering because of its requirement for drainage.