Q. Is there anything to
stop or suppress flowering of a Palo Verde tree? My wife is allergic to the
pollen and unless I can mitigate its effects, I guess it’s gone.
stop or suppress flowering of a Palo Verde tree? My wife is allergic to the
pollen and unless I can mitigate its effects, I guess it’s gone.
A. You are hitting on a
very important topic as we convert our landscapes into water conserving desert
landscapes. Before the conversion of landscapes from traditional to desert
landscapes, the three biggest problem trees for allergy sufferers were mulberry,
pine and olive.
very important topic as we convert our landscapes into water conserving desert
landscapes. Before the conversion of landscapes from traditional to desert
landscapes, the three biggest problem trees for allergy sufferers were mulberry,
pine and olive.
 |
| Olive flowers just before they begin to open |
Female
mulberries produce only fruit. Male mulberries produce only pollen. Years ago fruitless
(male) mulberry was planted because it was a great shade tree for the desert,
water for landscapes was abundant and the male tree produced only pollen. Female
mulberry trees made a mess on cars and sidewalks and birds who ate the fruit
dropped it everywhere.
mulberries produce only fruit. Male mulberries produce only pollen. Years ago fruitless
(male) mulberry was planted because it was a great shade tree for the desert,
water for landscapes was abundant and the male tree produced only pollen. Female
mulberry trees made a mess on cars and sidewalks and birds who ate the fruit
dropped it everywhere.
 |
| Pine getting ready to release pollen from the male flowers |
Pine
trees and olives were different. They also produced allergenic pollen but pollen
and fruit were produced on the same tree; male and female trees were not
separate from each other. Fruitless (and flowerless) olive was discovered,
promoted and adopted as the only olive tree which could be planted in major
urban centers like Las Vegas because it produced no flowers and hence no pollen.
trees and olives were different. They also produced allergenic pollen but pollen
and fruit were produced on the same tree; male and female trees were not
separate from each other. Fruitless (and flowerless) olive was discovered,
promoted and adopted as the only olive tree which could be planted in major
urban centers like Las Vegas because it produced no flowers and hence no pollen.
 |
| Mulberry flowers getting ready to release pollen |
Palo
Verde produces allergenic pollen on flowers that are both male and female in
the same flower. Comparing them to the above 3 trees, they are more similar to
olive than pine or mulberry. There are no flowerless Palo Verde, unlike the
olive.
Verde produces allergenic pollen on flowers that are both male and female in
the same flower. Comparing them to the above 3 trees, they are more similar to
olive than pine or mulberry. There are no flowerless Palo Verde, unlike the
olive.
Olive
fruit can sometimes be prevented by spraying the tree with a product like Florel
Fruit Eliminator. (contains ethephon). This product also controls the fruiting
of several ornamental plants (and sometimes the flowers) when applied just
before bloom. Depending on your Palo Verde, flowering will probably be in April
or May in our Las Vegas climate. You can read the label below
fruit can sometimes be prevented by spraying the tree with a product like Florel
Fruit Eliminator. (contains ethephon). This product also controls the fruiting
of several ornamental plants (and sometimes the flowers) when applied just
before bloom. Depending on your Palo Verde, flowering will probably be in April
or May in our Las Vegas climate. You can read the label below
I
hesitate to recommend this product because if it is applied at the wrong dose
it can cause leaf drop or possibly damage the tree. There is a recommended rate
for several ornamental trees including olive but Palo Verde is not listed on
the label. Use it at your own risk but if you are thinking about removing the
tree anyway it might be worth a shot. I am not sure who sells it in Las Vegas
but you cannot purchase it online.
hesitate to recommend this product because if it is applied at the wrong dose
it can cause leaf drop or possibly damage the tree. There is a recommended rate
for several ornamental trees including olive but Palo Verde is not listed on
the label. Use it at your own risk but if you are thinking about removing the
tree anyway it might be worth a shot. I am not sure who sells it in Las Vegas
but you cannot purchase it online.