Theodore Payne himself introduced the blue palo verde into cultivation, so I am especially pleased to have this update on its cultivation here at TPF, a story that involves our entire Horticulture Department.
The palo verde is an icon of the Sonoran Desert and an increasingly popular native tree in Southern California. Although its seeds germinate readily, palo verde cannot be readily cultivated from cuttings: seed is essential to its propagation. Seeds of the species are hard to come by in the trade, and its availability is outshown by the popular cultivar ‘Desert Museum’.
Theodore Payne Foundation is fortunate enough to have five specimens of the species, Parkinsonia florida, one grows just inside the nursery gate and four in our demonstration gardens at the top of the hill west of the pergola. TPF’s horticulturist helped the demonstration garden trees to thrive over the last few years, leading to a good crop of seeds. No one is quite sure why the nursery tree is less productive, but it could be that it is heavily shaded.
With ready access to seed, our team was on the job. Ripe seed pods were collected from the stock plants in August 2017. Seed program staff removed seed from pods, examined for them for pest activity and viability, assigned a catalog number, and then gave seed to propagation and offered some to customers through the store.
Our prop program sowed the high-viability seed from May 2018 until early summer. In general, as with many members of the Fabaceae family (particularly lupines), thick-coated seeds are soaked in hot – near boiling – water overnight and then sown immediately – in our case, directly into two-inch pots. By August, the rapidly growing seedlings were ready to be moved up to 1 gallon containers, where they grew to over one-foot tall within a short time.
On to the sales yard! TPF is offering 5 gallon and 1 gallon plants for sale this fall. Check the inventory for current availability. We are very pleased to offer this alternative for those who would prefer the species to the ‘Desert Museum’ cultivar.
Visit the mother plants at TPF!