Xtremehorticulture

Chosing One Product for Pest Control

Q, If you were to buy one product for insect control on plants, what would it be? Organic castile soap for mixing in an emergency. What you shoot, is what you get when using soap and water sprays! Probably the single most important insecticide all season but it is applied in the winter as a precaution. Insurance insecticide. A. Probably soap and water sprays or an oil but not a Neem-type oil. Soap and water sprays are deadly to all insects whether the insect killed is a good guy or a bad guy. With soap and water sprays “what you spray is what you will kill”. Be careful when you use soap sprays and spray only what you intend to kill. In many ways it’s like a gun.             The advantage of industrialized pesticides is that they stick around longer after you spray them. Soap and water sprays must be repeated more frequently to protect plants from undesirable insects but are perceived as more environmentally friendly. I always carry with me a bottle of soap for mixing with water in case I see an insect problem that needs my immediate attention.             In a pinch you can make your own soap spray by adding about one to two tablespoons of dishwashing soap to a gallon of water. I prefer using a pure Castile soap, that I am comfortable about, to mix with water.             The oils I’m talking about are the “horticultural oils” or “dormant oils” made from paraffin or mineral oil and not from the Neem plant. These types of oils have been proven to be very effective on soft bodied insects like scale, aphids, mites, and whiteflies. Follow the label directions when making an application. Don’t add soap to the concoction if it is already “homogenized” and has something in it that already mixes the oil and water together. Horticultural oils (don’t use Neem oil) comes in smaller and larger quantities.

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Dormant Sprays or Dormant Oil?

Q. I have a peach tree that has been in the ground one year. I was supposed to spray it with dormant oil spray before leafing out. Is copper fungicide okay for spraying in the spring? Want to avoid bad pesticides because of birds, good bugs, etc.  A. There is a confusion out there concerning dormant sprays and dormant oil. Dormant sprays can be a number of different types of sprays. The name “Dormant Spray” is a trade name and tells me nothing about its contents. Dormant oils or horticultural oils help prevent insect pests in the coming growing season If I have the trade name (Dormant Spray) and the manufacturer then I can look it up and I will know exactly what it contains. There is no hard and fast rule that you can apply when you are talking about dormant sprays. However, dormant sprays are usually a traditional pesticide or combination of traditional pesticides that are sprayed during the winter or early spring. Sometimes they contain a fungicide that has copper in it and sometimes they contain an insecticide as well. They are not typically organic. Dormant oils, on the other hand, are very specific. They vary a little bit among manufacturers but not like dormant sprays. There is no reason for spraying a copper fungicide contained in the dormant spray if there are no problems to solve. However, dormant oils are very important to apply as a preventive measure for controlling some of the insects common on fruit trees. There is no reason for spraying copper fungicide now unless you have a good reason for it. Be sure you have a SPECIFIC reason for doing this before you do it. On a one year old peach tree I doubt it unless you have disease pressure from Coryneum blight/shothole fungus.  If we have extended periods of wet weather or rain you might consider it after the rain has finished. But otherwise I would not do it.

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What To Do To Peach Trees in Late January and February

Q. Could you direct me to or post a list of things I should be doing to my peach tree now?  A. I will post the answer on my blog for others but right now you should be finishing up your pruning, fertilizing and begin irrigating once a week if you have surface mulch under the tree. Peach trees in early bloom this January. Normal bloom date is February 1, consistently, year after year. The warming spell in January kicked everything into high gear early. Let it finish blooming and then apply dormant oil to the entire tree to suffocate pests that are now coming out to attack leaves and fruit. Dormant oil is NOT dormant spray for disease control. In about one month you will look for peach twig borer damage to new shoots and applying Bt spray to control these moths and “worms” that attack new growth and later your peach fruits. Watch for the posting on my blog with more detail and pictures.

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Tree Damage from Dormant Oil?

Q. I need some help. About a month ago I was advised by a gardener that two ornamental fir trees needed to be sprayed. He suggested I use Ortho Volck and I did this at the prescribed dilution rate. Now both trees seem to be in trouble as shown in the attached photographs. Did I spray too heavily? What can I do to try to save these firs? “Fir” damage from oil A. Dormant or summer oils are not supposed to be applied to Douglas Fir, Spruces such as birds nest, many juniper and cedars. I assume Volck oil says this on the label. It may cause defoliation or needle drop. In some cases you might have some branch dieback, perhaps enough to ruin its looks. It is safe on pines if you follow the rate of application. You mention that you have fir trees which is unusual in the Las Vegas valley but if these are in any of these categories you could have spray damage. If the damage is not too severe I think they will drop damaged needles and show some new growth from terminal buds and buds inside the canopy (branches). Hopefully they will recover.

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