Xtremehorticulture

Xtremehorticulture of the Desert

Thin Your Peach Tree While Fruit is Still Small

Leave a Comment / how to get bigger peach fruit, small peach fruit /

Thinning fruit, or selectively removing fruit so remaining fruit gets larger, should be done at an early stage of fruit development. See examples of the spacing of fruit for good size. Flower removal so there are fewer fruit to pollinate can be dangerous if the tree does not get a good fruit set. Wait for fruit which was not successfully pollinated to fall from the tree. This should be just a couple of weeks after you see the fruit starting to develop. A gentle shake of the limb will confirm if the fruit has set or not. Peach before thinning Peach after thinning Peach before thinning Peach after thinning

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Apricot Leaves Cupping and Dropping

Leave a Comment / leaf scorch, leaves cupping, stinkbugs /

Q. My Blenheim apricot tree is not doing well. A few branches have lost all their leaves. Other leaves are starting to curl and cup. This past year it had plenty of apricots but few leaves. I thinned them out since the tree is young. I thought this would also help the tree put more energy into leaves.  Photos attached. I planted it in March 2012.  Although the branches were a little spindly the first year the tree appeared to be doing fine.  Looking at the photos, do you have any thoughts as to what might be happening. Apricot leaf cupping and scorching early in the season. Note: I made a trip to this residence to see if we could determine the problem. We found stinkbugs on the limbs of the tree. It was then very obvious that these insects may have caused the leaf cupping due to their feeding activity as the buds/leaves were expanding. Not much for them to eat that time of year but their feeding activity could cause leaf damage when the leaf is young and the expanding leaf could then cause the cupping to occur. Protective sprays early in the season would have helped prevent this. My answer below was before my visit and my thoughts as I looked at the pictures. A. First thing, I see you have wood mulch. Please pull it back 12 inches from the trunk. The symptoms you sent to me could be that. The cupping is because the outside edges of the leaves dried up and the leaf was still growing so the inside of the leaf still expanded while the dead edges did not. The edges of the leaves dying could be lack of water, salt damage, wind damage, damage from sprays. The lack of water could be either from a lack of applied water, damage to the trunk (mechanical or borers). Salt burn can be from applying fertilizer too close to the trunk and/or heavy rate of conventional fertilizers in the irrigation basin. Always keep fertilizer at least a foot from the trunk. When watering the fertilizer into the soil try not to flood the basin around the tree if you put a considerable amount of high nitrogen fertilizers such as ammonium sulfate or urea in the planting area. Urea or even “hot” manures like chicken or other poultry manures can cause problems like this if they get too close to the tree. Wood mulches surrounding young fruit trees and left in contact with the trunk can cause the trunk to rot effectively choking the tree at its base and causing it to act like it is not getting enough water (leaf scorch), dieback or death. This is called collar rot, crown rot or Phytophthora rot. Upon inspection of the tree if you have pulled the mulch back, inspected the trunk just above soil level and see no problems, inspected the trunk and see no signs of borer damage and ruled out possible damage from fertilizers then perhaps we can look at any sprays you might have applied and possible spray damage to foliage and fruit or damage from strong winds. Fruit trees do perform better with some windbreak in their growing area that either slows the wind down or causes it to be diverted to a different place.

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Japanese Blueberry With Orange Leaves a Sign of Leaf Death

Leave a Comment / drought, japanese blueberry, Las Vegas, leaf death, leaf pigments /

Q. My water accidently turned off for two weeks and my Japanese Blueberries are all orange. I do see new growth on the edge of the branches. Is the tree shedding old leaves? Did the cold snap in November cause this? Orange leaves on Japanese blueberry as they are dying and falling off. A. The orange color is the color of the natural pigments in the leaf as the leaf dies, its green chlorophyll disappears and leaves behind these orange or reddish pigments. These colors are typical of anthocyanins and related biochemicals. It is hard to say “after the fact” on something like this. All you can really say is that the leaves have died and will fall off. Now the question is whether “the death” went further than this or not. So you would normally take hold of the branches with dying leaves and bend them. If they are supple and the leaves drop then it was a recent “trauma” to the plant and you cannot be sure yet if the death is going further or not until you see new growth. You can be pre-emptive and cut these branches back and force new growth or wait, your call. The fact you are seeing new growth is very positive. You realize that Japanese blueberry is not the best choice for a carefree landscape in Las Vegas. It is best planted in a part of the yard protected from late afternoon sun and it will definitely not do well in a rock landscape.

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Quince Tree With Dark Brown Bumps on Branches

Leave a Comment / brown raised bumps on branches, quince scale insect /

Q. We have a 3 year old Quince tree which looked very good to me until today when I notice brown/dark purple small pee size bumps on the top branches. Removing the bumps causes a fluid to ooze out. I guess the fluid must be sweet since there are ants running up and down the branch. To readers: Sometimes the pictures that are sent to me are not the best so I have to do some “interpretation” on them. But I appreciate all pictures sent. They help alot. A. From your description and the pictures it looks like it might be one of the scale insects. I have never seen scale insects on quince in the Las Vegas valley but they do infest trees in some other climates. Scale insects, particularly the soft scales, will exude a sugary liquid that drips on limbs and leaves and attracts ants. They are easy to squish and act just like how you are describing it. There is an insect under the harder outer shell. Young are produced by the female and they leave the protection of the females shell, move about and find a new home where they can suck plant juices and also build a protective shell on the outside of its body. Soap sprays that are manufactured for plants are safer to use than mixing your own. The usual method of control is using horticultural oils and spraying the oil on the plant to suffocate the insect. If you are lucky enough to see the young emerge and start looking for a home most any spray will kill them including soap and water sprays like Safers insecticidal soap. But you will have to spray the oils and soap and water sprays through the year to get them under control. Once under control an oil spray in the dormant season such as winter months when it is warm should help keep the populations reduced. A wild guess from the picture, it might be brown soft scale particularly because you mentioned the ants.

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Will PawPaw Fruit Trees Grow in the Desert?

2 Comments / desert, how to grow, Las Vegas, paw paw /

Q. Do you know if paw paw trees will grow here? If so, what type of conditions (partial shade, full sun etc) and what type of soil amendments?  A. I have wondered the same thing myself. I have never tried them here in our desert but there are some pawpaws out there I would like to try. I have been told by Dave Wilson Nursey that they will struggle here but that just gets me more interested in trying them. I think if you have the right exposure, modified the soil and mulched them, they have a chance. These are the conditions I would try to meet if you decide to give it a go: They are very sensitive to full sunlight and requires filtered sun when young. Once established they can handle more sun but not OUR sun. Plant on the east side of the home landscape. Amend the soil with good compost to a depth of 18 inches. Amend the soil with AT LEAST 50% good compost. Acidify the soil with very fine sulfur or aluminum sulfate to help keep the soil pH acidic. They can have a pretty good taproot. Provide plenty of water just like you would any normal fruit tree but like any fruit tree do not water daily. Mulch the trees with wood mulch to a depth of three to four inches and keep it away from the trunk the first four years. Apply fertilizer twice a year; once in early spring and again in the fall. They can tolerate very cold winter temperatures. Also they do not set fruit very well so you may have to hand pollinate the flowers to aid them in fruit set and get more fruit on the tree. Some good information on pawpaws can be found at Kentucky State University where the national repository is located. Kentucky State University website for repository 

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Bamboo Damaged Just After Winter

Leave a Comment / fertilizer, how to prune, how to recover, winter cold, winter damage /

Q. Do you have any advice on what I can do to green up these bamboo planted in rock mulch? Give them iron perhaps? Bamboo from reader just after winter cold. A. I hesitated a bit because I was not sure which bamboo this was so I am guessing it is golden bamboo, a runner. The new leaves will come in this spring and cover most of the damaged ones. Otherwise you are left to removing the leaves by hand if it is unsightly. Come back? Fertilizer and water. An option is to cut them back and let them regrow with new shoots. The running bamboo grows from rhizomes or runners underground. Clumping bamboo grow like an iris and the clump just keeps getting larger. These can handle pruning but I would not top them. I would selectively cut out stems at the ground level where you don’t want them. Hope this helps.

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Orange Tree Flowering Now and Not December

1 Comment / citrus flowering late, grapefruit, lemon, lime, orange /

Q. We have an orange tree that did not produce any flowers this last December.  Over the last week in March the tree has started covering itself with buds all over. We inherited the tree when we bought the house last summer so I don’t know much about the tree.  Just that its only a couple of years old and produced a couple delicious oranges in December of 2012. I’d love to have some oranges, but is fruit coming this time of year bad for the tree somehow?  A. No, you are okay with the flowers. They should sail through the summer with no problem. They probably got hit with a couple of freezed we had in December and January. My biggest worry is a late freeze which did not happen so you should be good to go. The best fruit will have some shade covering so it does not get sunburned. If it is in a container try to double pot it or somehow keep the sun off of the outside of the container. Keep it well watered as you would any other fruit tree or nondesert landscape tree. They do better with some surface wood mulch. Depending on the orange you should have ripe fruit some time late fall or mid winter. Hope this helps. You may enjoy reading this publication from Arizona on citrus.   Arizona citrus publication

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Do Not Mulch Cat Claw Vine?

Leave a Comment / cat claw vine not growing /

Q. I believe in one of your columns regarding cat’s claw to avoid mulching the base of the plant.  Of course I had already done this and the plants are struggling where I very much want them to thrive and go nuts with no issues.  Six plants were planted 2 summers ago; they are on a drip system, and I hope to wean them from regular water once the granite mulch is covered; they receive full sun.  A. I don’t remember telling people to mulch cat claw. Cat claw vine is a very vigorous tropical and semi tropical vine that is one of those rare plants that does well in the tropics and the desert. In fact it is considered an invasive plant in much of the southeastern US to east Texas.  It has been declared a huge pest in coastal Australia where it climbs over everything and in places where there is 43 to 40 inches of water a year minimum it will begin to suffocate neighboring plants by climbing all over them. Not so in the desert where we can restrict its growth with drip irrigation. It can tolerate a wide range of soils. They may have some trouble getting established on really hot walls during summer months. But once they cover the wall they will do a good job shading it and reducing the reflected heat from that wall and glare. It does like to grow along waterways and so would be a pretty bad pest if it escaped along the Colorado River or any of our surface waterways in lower elevations of southern Nevada. It is a beautiful vine, it is aggressive and nearly pest free. It may die to the ground during cold winters or just drop its leaves when it gets below freezing. It will do well in rock mulch provided it gets adequate water. I would not allow it to climb on stucco or house siding for more than a couple of years. When it does, pull it off and cut it back and let it regrow a different direction. This should be trained to cinder block walls or the like. I would not plant this vine in wet climates. In your particular case I would pull the wood much away from the trunk at least a foot until it gets firmly established. Fertilize once a year in the early spring to push new growth. It loves the heat so fertilizing lightly during summer months will not hurt it. As it gets older it tends to get woody at the base revealing wood stems. To reinvigorate it cut off one of the older stems and let it regrow with new leaves to cover bare areas. Also as it gets older it will get top heavy and fall back on itself creating a very interesting look. You can also cut it back to the ground in late winter after it has been established a few years. The underground tubers will send up new shoots that will start the vine all over again. It can be propagated by these tubers as well. Information on cat claw vine from Arizona Master Gardeners

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My Onions are Not Growing

Leave a Comment / how to grow onions, how to plant onions, onion problems, onion slow growing /

Q. I bought a package of onion sets several months ago. They aren’t getting big. Hopefully, some of them are not dried out. Regardless, I have some onions growing in my garden now and could use some ideas.  They’re mainly purple onions. A. If they were transplants and dried out then this could be a setback for them. Onion sets are already dried so not a big deal if you didnt get them growing good and then they dried out. When you plant transplants they will wilt for the first couple of days. The tops fall over and then they perk right up provided the soil was prepared properly and you are watering regularly,…daily the first couple of days. Make sure you planted the sets and transplants the correct depth. Sets (which are just dried down little onion bulbs) are planted about an inch deep. On transplants you will see a fairly clear distinction between the part that was growing above ground (green) and the part growing below ground (white). Plant them at the same depth they were growing before, using the color separation as a guide. Onions first put their energy into their tops so the tops will get big and the bottoms do not until we get the right number of hours of darkness (some say daylight but it is really the darkness that is the trigger). After soil preparation then I disagree with some people out there who tell you not to fertilize with nitrogen. You need to side dress onions with nitrogen fertilizer every 30 days until the month of harvest. Make sure you water the fertilizer in generously. The size of the onion bulb is related to the size of the tops you are growing so sidedress regularly with high nitrogen fertilizer. Once the trigger for bulbing starts there is not much you can do that will stop it. When you see the flower produced on one of those green leaves pull it off and don’t let it develop unless you are using the onion flower for something culinary or decorative. Remove onion flowers as soon as you see them. Dont let them get this big before you do unless you plan on using the flower for culinary purposes or decorative. It just takes energy away from bulb development. Harvest once the tops fall over. Wait for each one to fall over. They will be different and fall over at different times. Let them cure for a couple of days in the shade or in the house before you store them for any length of time. Once the tops dry down you can cut the tops off to within a couple of inches of the bulbs. Harvest onions when the neck can no longer hold up the weight of the top and it falls over. You can harvest it earlier but it wont keep very long. Still tastes great though!

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Holes in Trees Due to Woodpecker?

Leave a Comment / borers, holes in trees, sapsucker, woodpecker damage, yellow-bellied /

Q. Do we have woodpeckers in Las Vegas?  This is the north side on the trunk of my Carob tree, at about chest high. The trunk is 5″ to 6″ in diameter.  The reason that I checked the trunk this morning is that I saw a bird perched there apparently pecking and went out to see if there were ants.  I found no similar pits in another carob tree that is older.  Readers picture of sapsucker damage to carob tree. A. We have sapsuckers that come through Las Vegas this time of year and they cause that type of damage. I wrote about this on my blog a couple of years ago. Trees can live quite a long time with this kind of damage. Birds frequently will come back to this tree in future years. I have had apples with over ten years of damage and still doing okay. Otherwise you have to do something to keep them from getting to the tree. Previous posting on sapsucker damage on Xtremehorticulture

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