We are seeing quite a bit of fireblight damage to the new growth of pear, Asian pear and apple right now. This is new stem growth that is turning black and, in some cases, this new growth is curving back as it is dying.
Fireblight is a bacterial disease with the only cure being cutting or pruning it out. If the disease symptoms this spring are the result from last year’s disease problem, make your cuts to remove these branches at least 12 inches below the damaged area.
Sanitize pruning shears or any saw that you might use with alcohol, diluted bleach or other sanitizing agent. Do this between each cut made so it is not carried from branch to branch or tree to tree.
Q: We have a big pomegranate tree that has been doing great for a few years. Last year we had an infestation of nasty, prehistoric looking large gray bugs with really big thighs and smaller red ones that look like a cross between a carpenter ant and a mosquito. What I can do to get rid of them. We have been keeping it organic up until this point and would love to continue that since we eat as much of the fruit as possible.
A: These insects are called the leaffooted plant bugs, a close relative to stinkbugs, squash bug and several others that are pests in home landscapes and gardens. The smaller red ones were the babies or nymphs. They get their name from the leaf-like appendage on their rear legs.
They spend the winter hiding out in landscape trees until spring. In the spring, these bugs multiply very rapidly and feed on new soft, succulent growth from leaves and expanding fruit and nuts.
This insect seems to prefer fruit and nut trees such as pomegranate, almonds and pistachios but can be found on other plants as well.
They are winged so the adults can fly from plant to plant, tree to tree or landscape to landscape. Their damage to plants includes leaf damage, leaf drop, fruit damage, fruit drop and nut drop in almond and pistachio.
Control of these insects is more difficult with organic methods. This will require quite a bit more work on your part.
Organic sprays would include soap sprays such as Safers, oils such as Neem and pyrethrin sprays. Organic sprays are usually not as potent as conventional commercial insecticides. So organic sprays may have to be used more often and will require closer monitoring of the plants for buildups in their populations.
Spraying multiple times through the growing season will be required because of their abilities to build their populations so quickly and their ability for flight.
Q: My son got me onions that were little 3-inch sprigs with roots, no bulbs, tied together in a bunch, no soil. We separated them and planted a few months ago. They have grown about 7 inches or more tall and I just noticed today some of them are getting seed bulbs on their tops. Why are they going to seed already?
A: Yes, that is the flower being produced. Early flowering can be caused by up and down temperatures in the spring or irregular watering.
Pull or cut the flowers off unless you want to use the open flower for culinary purposes. Do not let them go to seed.
Continue to fertilize onions once a month. The safest way is to put some fertilizer that dissolves easily in water and pour the fertilizer solution around the plants evenly.
Otherwise “side dress” a dry fertilizer in a narrow band about 2 to 4 inches from the plants in a line parallel to the row. Water it in lightly with a spray nozzle. Do not get dry fertilizer too close to the plants or you can damage them.
Do not harvest until the tops of the plants fall over. That is your clue to go ahead and harvest them over the following week or so.
They will also benefit from a surface layer of mulch. This can be shredded newspaper (black and white only) around the plants.
Q: There’s a glossy sheen on my rose leaves that’s not supposed to be there. I have this problem every year and I usually just give them a good spray with the hose. This helps but doesn’t seem to be the cure. Any suggestions that don’t involve chemicals?
A: I think what you are seeing may be some residue from some feeding insects on roses. These insects excrete (release) a sugary substance from their feeding that falls on plant parts such as leaves.
If this is what you are seeing it should be slightly sticky and may attract ants and bees that will collect this residue for feeding.
These insects suck out plant sap that contains sugars for their own feeding. There is so much sugar in the plant sap that their excretion contains a lot of sugars.
Insects that release this kind of “honeydew,” as it is sometimes called, include aphids, scale insects, leafhoppers and whiteflies. Roses aren’t the only plants these insects feed on. We will seed them on most trees, shrubs and even pines.
Repeat applications of soap and water sprays will usually control them until hot weather comes. High temperatures are not a good thing for insects like aphids and help to keep them under control until the cool fall weather sets in when we may see them again.
Q: I planted an All-in-One Almond, Saturn Peach, 5-in-1 Apricot and, most recently, a Pink Lady Apple. My almond has not leafed out yet. The others have. The stems are still green and flexible, but there is some dieback at a few tips. It has been five to six weeks in the ground. Could this be transplant shock of some sort?
A: Apples and pears are a little slower to come out than other fruit trees. They are slow to start growing in the spring. Have some patience.
Do not water more than twice a week right now but it should be a good thorough watering each time. The biggest problem now is to water them too often.
Make sure you planted them the same depth as they were in the container. Do not plant them deeper than this or they can get collar rot.
When you planted them, you should have a basin around the base of the trees about 3 feet in diameter. Use this basin to collect water from a hose for the first two weeks after planting. This is in addition to any water from drip emitters you are using.
Watering from a hose on top of the planting hole helps to eliminate air pockets that are created during planting and wash out any excess salts that might be in the soil.
You should see a good flush of growth. You can stop hand watering with a hose after this flush, get rid of the basin and revert to drip only.
Cover the planting area in wood mulch keeping the mulch about a foot from the trunk the first four or five years.
Bob Morris is a horticulture expert living in Las Vegas and professor emeritus for the University of Nevada. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.