• Olive Trees and Mulberry Trees are known to be pollen-producing trees.
• Banned from Phoenix and Tucson since the 1960s, Olive Trees have become one of Arizona’s most notorious contributors to seasonal allergies. It got so worse that the Phoenix city ordinance has prohibited the selling and planting of male olive trees since 1986.
• They contribute to allergies and respiratory problems.
• According to Phoenix City Code: The planting and replacement of pollen-producing olive trees or mulberry trees is prohibited.
• Is it legal to plant Mulberry Trees? Yes and No. It is legal to plant FEMALE Mulberry Trees since they DO NOT produce pollen, only the MALE Mulberry Trees are illegal since they produce pollen (The Green Yard, youtube.com)
• Mulberry pollen is highly allergic to some people. Some regional municipalities restrict (or have outright banned) the planting of mulberry in public landscapes, except for the planting of non-flowering forms. (https://www.public.asu.edu/morusalba)

Is there a type of Olive or Mulberry Tree you can plant in Arizona?

1. There is a low-fruiting Olive tree called “SWAN HILL” that can be planted and replaced.
2. Moon Valley Nursery offers a fruitless Olive tree also called “Olea Europaea Wilsonii”. They have the same characteristics as the Manzanillo trees and Mission Olive trees except that they do not bear fruit. This tree has been approved by The Clark County, LV, NV, Department of Air Quality. (moonvalleynursery.com: “fruitless olive”)
3. For homeowners who would like to bring the olive tree’s Mediterranean aesthetic to their landscape without the accompanying fruit drop, consider these non-fruiting, non-pollinating varieties:

• Swan Hill (Olea europaea ‘Swan Hill’): This tree thrives in full sun
  to partial shade and is an excellent choice for shading a patio.
  30’H by 30’W.
• Wilsonii (O. europaea ‘Wilsonii’): This cultivar of the Manzanillo can live for hundreds of years. 25’H by 25’W.
• Majestic Beauty (O. europaea ‘Monher’): Elegant and hardy, this variety has a wide shade canopy. 30’H by 25’W.
• Little Ollie (O. europaea ‘Montra’): Ideal as a potted specimen, for lining walkways or as a sheared hedge. 6’H by 6’W.
• (Celebrating the Mighty Olive Tree)

Much to anyone’s surprise, there are some trees that are prohibited from planting in Phoenix, Arizona. What are these trees and why are they banned?

An Olea European, commonly known as Olive Tree, is known to thrive in Phoenix. They grow very well in hot and dry climates. They can grow from 3 to 12 meters about 10 to 40 feet and have numerous branches. Olive Trees are used for Mediterranean, xeric, or oasis design themes, and residential, commercial, or industrial plantings. They are low maintenance, drought-tolerant, and can provide shade and privacy to your beautiful home. Olive Trees have long lifespans, with proper care they can easily live for 50 years or more.

Meanwhile, Mulberry Trees, scientific name: Morus Alba, are native to Asian and North American countries. People named the mulberry tree after the fruit of bears, mulberries. Not all these fruits though, are safe for human consumption. The white or unripe mulberries are toxic for people. They contain poisonous sap, which leads to symptoms like upset stomach, heightened nervous system, and hallucinations. Humans can safely consume the red and black mulberries as they are rich in vitamin C.

So, why are Olive and Mulberry Trees banned/illegal in Arizona? Simply because they are pollen-producing trees. Banned from Phoenix and Tucson since the 1960s, Olive Trees have become one of Arizona’s most notorious contributors to seasonal allergies. It got so worse that the Phoenix city ordinance has prohibited the selling and planting of male olive trees since 1986. Does this mean ALL kinds are prohibited from being planted? Yes and No. It is legal to plant FEMALE Mulberry Trees since they DO NOT produce pollen, only the MALE Mulberry Trees are illegal since they produce pollen. While there is a low-fruiting Olive tree called “Swan Hill” that can be planted and replaced. Moon Valley Nursery offers a fruitless Olive tree also called “Olea Europaea Wilsonii”. They have the same characteristics as the Manzanillo trees and Mission Olive trees except that they do not bear fruit. This tree has been approved by The Clark County, LV, NV, Department of Air Quality. Other non-fruiting, non-pollinating varieties are Majestic Beauty or the Europaea ‘Monher’ and Little Ollie or the Europaea ‘Montra’ which can be used as a wide shade canopy and for lining walkways or as a sheared hedge.

It is still essential to consult with local authorities or agricultural extension services for any specific regulations or guidelines regarding planting trees in a particular area. Regulations can vary depending on factors such as local ordinances, water conservation efforts, and the potential impact on native ecosystems. Therefore, while olive and mulberry trees are not inherently illegal to grow in Arizona, it’s important to be aware of any relevant regulations and to choose tree species that are suitable for the local climate and environment.