A Quarter Century of Quality and Consistency: ‘Variety AZT’ Turns 25
When Arid Zone Trees began to grow specimen sizes, desert adapted landscape trees, in 1982, trees were grown from collected native seeds. It quickly became obvious that this method of propagation produced trees that were highly variable physically (appearance) and horticulturally (growth and development over time). Cloning or vegetative propagation was the best option for producing wholesale quantities of trees with uniform, desirable characteristics. We approached cloning desert trees with two principles in mind: first, that there are many individual trees within a given desert tree species that may exhibit desirable characteristics for landscape applications; and second, that all trees developed and marketed by ‘AZT™’ needed to possess attractive physical and durable horticultural characteristics. To satisfy both goals we embraced a multiple clone approach. By identifying a number of trees from within a single species with desirable characteristics, we can offer a high level of uniformity while maintaining genetic diversity. Our search for new trees to clone is ongoing and offers the opportunity to introduce new clones when suitable selections are identified.
Chilopsis linearis ‘Desert Amethyst’
As an alternative to seed production is vegetative propagation (also called clonal propagation or cloning), plant parts (typically fresh, lush, green stem growth) are treated with plant growth hormones to encourage the formation of roots. Once rooted, cuttings are then grown like seedlings to produce new trees. In this way new plants, genetically identical to the original "mother" plant, are produced. Cloning provides a useful method for producing large numbers of genetically uniform trees with similar form, structure, flower color, leaf pattern or any other desired quality or appearance. The challenge in bringing cloned trees to the market has always been to 1) select trees with the desired physical characteristics (branch structure, flower color and amount, foliage) that also possessed sound horticultural qualities (well-distributed root mass, cold hardiness, growth rate and form) and 2) to successfully and efficiently produce these clones on a large scale. Careful selection and evaluation of foundation stock (“mother” plants), in conjunction with cloning techniques, can improve tree performance. Without careful screening, physically attractive trees can be introduced that are, in fact, genetically vulnerable to an assortment of unanticipated problems.
Cercidium praecox 'AZT'
We use the ‘AZT™’ Variety name on all our cloned trees to allow us to add new selections as they are identified while still assuring our clients that all selections are the product of our screening and evaluation process. What began as a effort to produce more uniform Thornless Mesquites have grown to include 11 varieties:
Acacia smallii ‘AZT™’, AZT™ Sweet Acacia
Cercidium hybrid ‘AZT™’
Cercidium praecox ‘AZT™’
Chilopsis linearis ‘Bi-Color’
Chilopsis linearis ‘Desert Amethyst’
Chilopsis linearis ‘AZT™ Dora’s Desert Rose’
Olneya tesota ‘AZT™’
Prosopis glandulosa thornless ‘AZT™’ Thornless Honey Mesquite
Prosopis juliflora (velutina) ‘AZT™’, Native Mesquite
Prosopis seedless hybrid ‘AZT™’
Prosopis thornless hybrid ‘AZT™’
All ‘AZT™’ varieties epitomize Arid Zone Trees’ commitment to quality and innovation in desert adapted landscape trees.
Chilopsis linearis ‘AZT™ Dora’s Desert Rose’