Xtremehorticulture

Replanting In Same Hole for Fruit Trees Usually Not a Problem if Borers are the Reason

Q. I removed a diseased (clarified by saying the only problem was borers) peach fruit tree.  How soon can I plant another peach tree in the same hole? A. If this is from borers, then you can plant immediately. Not a problem with borers and replanting. The entire lifecycle of the borers in our fruit trees are in the aboveground portion of the trees, not the roots or soil.             There is a problem potentially with something called replant disease but it is minor in this case and should be not a problem for you. Remove as much of the root system as possible before planting.

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When to Transplant Fruit Trees?

Q. With this unusually mild LV winter, when is the best time to transplant dwarf grapefruit trees? A. By transplant I take it to mean you are moving a grapefruit from one location to another location. Planting or transplanting can be done now. You will have more success if the tree has not been in the ground more than three years. You will have even more success if the tree has been watered by drip irrigation in a fairly small basin or area next to the tree. You will have even more success if the tree was root pruned last fall around mid to late September. Roots of M111 on 12 yo Anna apple. We remove fruit trees from the orchard as we learn about them and then move on to those varieties we have not explored. Root systems can get large quickly and make it no longer feasible to relocate older fruit trees to new areas after about three years in the ground             Root pruning just means you went around the entire tree with a shovel and severed the roots in the approximate location where you are planning to dig and transport it. Given all that, prepare your hole for planting first before you move the tree. Dig deep enough to accommodate the root ball but not much deeper.             It is more important to dig it wide than it is to dig it deep. Get your soil amended and add some phosphorus to the soil. Move your tree as quickly as possible to its new location and try to orient it in a similar orientation, north to south, as it was in the old location.             Backfill around the tree. During planting, run a hose in the hole at the same time you backfill to remove air pockets. Drive a stake next to the tree and into the bottom of the hole into solid ground. This stake will immobilize the roots if tied to the tree tightly.             I usually use rebar pounded into the soil next to the tree after it has been planted. I wrap the tree and rebar together with green nursery tape to immobilize roots. This leaves the top to move in the wind.             The trees should be planted the same depth as it was when it was removed from the soil. No deeper and no shallower. If you have rabbits, protect it with one inch chicken wire after planting. Mulch the soil around the tree with wood mulch keeping the mulch away from the trunk a foot. After one season of growth, remove the stake.

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Hobby Greenhouses a Special Challenge in the Hot Desert

Q. My helpful husband gave me a 6 x 6 foot greenhouse for Christmas and I’m wondering what in the world I can do with it here in Las Vegas. I am thinking that I can get a head start on growing seedlings and things like that, but during the summer months, it will probably be a storage area since it’s so hot here.  I have it located on concrete on the southwest side of my house, and unfortunately there is no other place for it. Also, maybe I can extend the season into winter months? Any information would be great. A. That was very thoughtful of your husband. As you have probably already figured out, greenhouses can be tough to manage in our climate. But it can be done. You have one thing going for you. You have a greenhouse. What you don’t have going for you is that size and its location.             Small greenhouses are difficult to manage in this climate because they heat up so rapidly. By modifying your greenhouse you may only have to shut it down for two or three months during the summer. Generally speaking in hot climates with lots of sunshine, tall greenhouses are better than short greenhouses. Anything you can do to make the greenhouse taller is a good thing. The heat accumulates toward the top of the greenhouse. As the heat builds it puts heat on the crops growing lower. The taller the greenhouse, the easier it is to keep the heat off of the plants. That Southwest exposure is also tough in the summer but would be nice in the winter.             During the summer the sun is nearly overhead and in the winter it is at a low enough angle that it mostly comes in through the side walls. You might want to consider orienting your greenhouse so that the door is on the East or North side.             Next, I would put some shade cloth on the roof or paint the roof with white latex paint to reduce your solar load. There is some bamboo fencing that is quite reasonable that you might consider placing over the roof to create some shade during the summer months.             These are all options. I would probably look at the bamboo fencing first since you can kind of adjust it by putting more or less of it on the roof. These should be done on the outside of the roof, not the inside.             If it’s possible, you might consider putting a couple of vents in the roof that you can open or that will automatically open for you if there is too much heat in the greenhouse. This will allow some of the heat that accumulates at the top of the house to exit and will help reduce the heat load somewhat. It will not cure the problem but it will reduce the problem.             You might also consider a small swamp cooler that draws air from the outside. Put it on the cooler north or east side if possible. It is also important that the greenhouse is not sitting in a rock landscape.             If it is surrounded by rock, it will compound your problem. About the most you will be able to drop the temperature from that little swamp cooler is going to be about a 20° difference from the outside air temperature.             Another way to drop the temperature is to replace one wall, or build into the wall, a pad system similar to commercial greenhouses. This uses recirculating water just like a swamp cooler but the pad is built right into one of the side walls.             On the opposing wall is a fan that pulls air through the wet pad cooling the inside of the house. If the pad is 4 to 6 inches thick, it could cool the house significantly provided you reduce sunlight entering through the roof.

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Moorpark Apricot a Good One for Las Vegas

Apricots on short shoots called spurs Q. We have a beautiful 5-year old Moorpark apricot tree. It has grown well and looks quite healthy. However, it seems to put out a sparse array of blossoms in spring and has a very light crop of fruit every year. The fruit is delicious. I read that the chill factor for this cultivar may be higher than our climate provides. Can I increase the chill factor by watering the branches in winter on cool days to lower the tree’s temperature and thus increase the chill factor? If successful I could get a larger crop? A. Moorpark is a wonderful apricot variety and is used extensively in the canning and fresh fruit industry in California. It is best if it receives about 600 chill hours during the winter. This means that the temperature should drop below 45F for at least 600 hours for the best fruit set. Apricot branch in the winter with spurs clearly visible However, don’t worry about the chill factor in this case. We have Moorpark and it has good fruit set here even after 18 years at our chill hours. The problem is more likely the fruiting spurs or lack of them. These will be the short branches along the major branches.  If these were pruned off, damaged or never developed then the crop will be light due to a lack of flowers. This year was a bad year for apricots. We had good weather and then it turned very cold in March. That freeze reduced our orchard apricot production from about two tons down to about 200 pounds. We have had no problem with Moorpark and irregular production and it has been a wonderful producer in most years. Perhaps the location of your tree in a particular microclimate of your landscape or how it has been pruned may have more to do with it than the variety itself. But a lack of chilling is not the problem. 

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Harvesting Herbs and Easily Damaged Vegetables

Nothing is worse than harvesting herbs and eggplant and by the time you get them in the door they are withered or soft and no longer firm. Or your products didn’t last very long in the cooler. Here are some suggestions on how to harvest these tender plants from the garden and keep them fresh. The ideal time to harvest most herbs is as early in the morning as possible. This is the time of day when temperatures are lowest, humidity is highest and winds are low. This is also the time for herbs when those volatile oils that are so important are at their peak and flavors are best. Harvesting should be at a time when the flower buds are just starting to form but before they open. When the flowering cycle begins, the plant begins to shove nutrients at the flowers and subsequent seeds which takes precedence over the production of leaves and stems. Flower formation indicates this loss of nutrients in leaves and stems is about to happen. After some familiarity you will begin to visually predict when this occurs as you note changes in the growth of the plant. If at all possible, spray herbs and soft vegetables with a mist of water 10 to 20 minutes before harvesting to wash dirt from the surface, cool the plant down and rehydrate the surface. In the case of vegetables, the larger the vegetables the longer it takes to cool the plant down. So don’t expect that a quick rinse of eggplant for instance to have much impact in cooling the fruit down internally. In our dry climate the cooling effect from spraying a plant down with water may last ten minutes at best and then the temperature begins to climb back toward the air temperature quickly. On the contrary, a light mist of water on the surface of most delicate herbs and leafy vegetables will cool the plants down considerably. Make sure you take a clean bucket with cool, clean water (non chlorinated would be best) into the field with you. During summer months the water temperature should be at least cool to the touch and cooler than the air temperature. For those requiring more exacting guidelines you should have temperatures about 55 to 65 F. There are some plants that can be packed in ice while others cannot. Icing is usually reserved for cold hardier plants like broccoli, spinach, cilantro, parsley, green onions, and Brussels sprouts. Icing more tender plants will result in injury. The four major enemies to plant quality and storage life occur after harvest: damage from handling, low humidity and water loss, high temperatures, and direct sunlight. Do everything you can to keep these enemies from damaging your harvest. Damage from handling. Harvesting requires a sharp and sterile knife or shears. Herbs and soft vegetables should be severed from the plant cleanly without tearing or ripping and lifted rather than pulled and immediately immersed in clean, cool water. Any surface tearing or scarring impacts the quality of herbs and soft vegetables and their storage life. If you have long fingernails or wear jewelry on your hands that could tear or rip, wear thin plastic gloves to protect these tender plant parts from damage. This may sound like these precautions are “overboard” but if you expect to store these plant parts for any length of time, damage to the surface of the plant allows water to be lost and disease pathogens entrance. All herbs and soft vegetables have to be inspected for damage and sorted for quality. Sorting or grading of products, if not done carefully and out of harsh conditions, can intensify damage and result in even more losses. Low humidity and water loss. Our desert climate is naturally low in humidity. That is great for growing plants but not so after harvesting. As soon as the herbs or vegetables are severed from the plant its source of water is removed, air enters the stems, water no longer moves through the severed plant part. Plants with roots attached can lose water from leaf and stem surfaces and water from the roots replenishes lost water. This keeps the leaves and stems hydrated and cool. Evaporation of water from leaves and stems helps cool the plant. As water is lost from severed plant parts their freshness and quality is compromised. Immersing them in cool, clean water immediately after harvest helps keep these products hydrated and fresh. Keep these plant parts out of the wind, direct sunlight and high temperatures which drive excessive water loss. High temperatures. It should go without much explanation that harvested plant parts should be kept cool unless you are dealing with vegetables that require high temperature and humidity after harvest such as sweet potatoes.Direct sunlight. The energy from the sun can be deceivingly destructive. I don’t know how many times I have told people in the field to put harvested products in the shade, even if it is under the shade of other plants. This is one of the most commonly abused practices after harvest. I observed small-scale producers in Kenya on the slopes of Mt. Kenya harvesting products and putting them in direct sunlight to be picked up by the co-op truck a few hours later. To top it all, these products were sorted and graded at the co-op headquarters by co-op members in DIRECT SUNLIGHT! Coop members then did not understand why half or more of their harvest was rejected by the exporter. Cleaning. A light salt solution (two tbs per five gallons or 35 g. per 20 L) can clean products of insects without damaging plant parts. Straight table salt, sodium chloride, has two chemicals that can cause plant damage; sodium and chloride ions. If too intense, damage will result. A better salt might be a potassium based salt rather than sodium which can be very toxic to plants. Immerse the plant parts in salt water, remove and dry in a salad spinner and place in a

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