During the spring of 2021, a Prescott College class purchased a few native trees and shrubs to plant at Watson Woods Riparian Preserve. The class got four of ten plants installed in May and Prescott Creeks hand-watered them until the monsoon began.
During the summer, Prescott Creeks noted a number of small Arizona walnut trees sprouting in the yard of the office – presumably stashed by squirrels for later retrieval. Knowing that these little trees would not survive due to periodic mowing of the yard, they were transplanted into #1-sized nursery pots. That fall, Prescott Creeks staff noted several Velvet ash trees in the Preserve that had produced copious amounts of seed. One of these trees was the survivor of multiple wildfires in the Preserve (ca. 1997 and 2005). Seed was collected and then grown by a Prescott Creeks volunteer in their home greenhouse.
By July this year, both the Arizona walnuts and Velvet ash trees had grown into #5-sized nursery containers and were ready for planting. Monsoon moisture is a great benefit to plants in the watershed. At Watson Woods Riparian Preserve, we’ve taken advantage of this moisture by planting native trees along the South Loop Trail this summer – with the intent of increasing biodiversity and restoring vertical habitat lost when Siberian elms (a non-native species) were removed. While these trees would naturally grow up in the shade of other trees, the planted trees are out in the open but “protected” with small brush piles to create shade and help soils around the trees retain moisture. It may also protect them from herbivory (being eaten by animals).
While installing plants this year, we did a quick sample of survivorship for the plantings from last year. Data showed a 64% survivorship rate – which was slightly lower than anticipated. We expect a much higher percentage of plantings to survive this year since they are benefitting from what might become one of the top ten wettest monsoons!