Xtremehorticulture

Tree Planting Requires Proper Hole Preparation in the Desert

Q. I had a boxed mastic tree planted recently. I didn’t like how it was planted. It was planted with the trunk not straight, the top of the roots exposed, the soil in the hole was dry, and I had them remove the bottom of the box. They were going to plant it with the bottom of the box still under the root ball. Mastic tree planted too shallow. Also the area is very small for such a large tree. A. I looked at the pictures you sent to me, and I agree it was not planted well. Sloppy planting. The hole was dug too small, and it was not planted deep enough. About 30% of the soil should be amended for drainage and moisture retention. Out of sight, out of mind. The soil surrounding your tree may or may not have enough amendments added. Watch this video on planting trees in Arizona that I thought was pretty good. Mastic (Pistacia lentiscus) trunk was planted with the trunk at an angle which is less of a problem than the exposed rootball (above).             Mastic is related to pistache (Pistacia lentiscus). Like all pistache trees, it is mesic in its need for water. This tree is Mediterranean in origin rather than western Chinese or Central Asian. Water requirements for both are similar and both develop red fall color. It grows well in a lawn where it gets plenty of water or surrounded by other mesic shrubs for the same reason.             When planting on a slope, the lowest side of the hole should be used for judging the hole depth. Add water at the top and sides of the hole, not the bottom. This tree is fine growing in soil covered in rock. If this tree shows signs of poor growth in a few years, add a layer of compost on top of the soil and water it in. Water should be applied on the “uphill” side of the tree but three feet at least from the foundation of the house. Dry Hole Problems             The problem planting in a “dry hole” is removal of air pockets. Dry soil pushed into the rootball (and using the butt end of a shovel to shove it further) may or may not remove them. Usually not. When planting in a slurry of soil the air pockets are removed at planting time (look for the bubbles), less “transplant shock”, and less concern about tree stability (staking) after planting. Air pockets in the soil will not do that. Wet the Soil             Making a slurry is easy to do. Just use a hose during planting. Sometimes a dry soil can be compensated in the first few months by circling a moist rootball with a “moat” or donut on top of the rootball when planting and wetting the soil after planting. Either that or apply water slowly or several times to get it to soak in.             This tree grows about 25 feet tall with about the same spread when fully mature. Pay attention to branch direction and the house when planting. Dig the planting hole at least three times the width of the plant container. Amend the soil removed from the planting hole with “organics” of some sort to keep the soil loose, friable, and well drained after planting. How Close to the Home?             I wouldn’t plant it any closer than 8 to 10 feet from a house to accommodate the watering and branch growth. Trees should be planted as close to vertical as possible. When trees are planted from a wooden box, usually the bottom of the box is removed first, and the sides are removed after lowering it into the hole. Fill the hole half full and then ADD water to make a slurry. Never add dry or hot soil to a planting hole.

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Favorable Growth of Trees in Soils Amended with Compost

Effect of organic amendment for the construction of favourable urban soils for tree growth L. Vidal-Beaudet1,4, G. Galopin2 and C. Grosbellet3 1 Agrocampus Ouest, Centre d’Angers, Unité de Recherche EPHor, Angers, France 2 Agrocampus Ouest, Centre d’Angers, UMR IRHS, Angers, France 3 Florentaise, Le Grand Pâtis, Saint Mars du Désert, France 4 IRSTV-FR CNRS 2488, Ecole Centrale de Nantes, Nantes, France SUMMARY  Ornamental tree planting and establishment in cities is a great challenge because urban soil physical properties are unfavourable to the development of root systems. Our objectives were to measure (i) the effects of organic matter on soil physical properties and tree development, and (ii) the effects of ensuing root development on soil physical properties. Using twenty-four 600-L planted or bare soil containers, we monitored physical properties such as dry bulk density, aggregate stability and near-saturated hydraulic conductivity of our reconstituted soils over a 5.5-year period. A 28-cm thick top layer of sandy loam amended with 40% (v/v) sphagnumpeat or organic composts was laid on top of a 28-cm thick layer of sandy loam. Bare-root Ostrya carpinifolia trees were planted in half of the 24 containers, and we monitored shoot development and root biomass and distribution. After 5.5 years, trunk diameter had increased from 59 mm for the control soil to 66 mm for soil mixed with green waste compost, and 74 mm for soil mixed with co-compost of sewage sludge and wood chips. After 4.5 years, trunk diameter was strongly correlated with the total number of axes (r=0.94) and fine root length density (r=0.98), and was confirmed as a good indicator of tree development. Fine root development increased stable aggregate formation in all treatments as compared to bare soil. After 4.5 years after planting, the tree root system induced by a high organic matter input had significantly improved near-saturated hydraulic conductivity and was fit to support fertile urban soils. Keywords aggregation, artificial soil, compost, Ostrya carpinifolia, tree development, urban horticulture Significance of this study What is already known on this subject? The quality of the constructed soil used for backfilling the tree pit plays a major role in tree performance. Soil organic matter content also plays a key role in agronomic fertility, so the use of organic amendments and especially composts appears as an ideal solution to boost urban tree growth. What are the new findings? The addition of high levels of organic composts immediately improved the soil physical properties (e.g., dry bulk density, aggregate stability and hydraulic conductivity) and in return fine tree roots modified soil structure and decreased dry bulk density in the top layer. Correlation coefficients confirmed trunk diameter as a very good indicator of tree above and belowground architecture. What is the expected impact on horticulture? Sustainable tree planting and establishment in cities is a great challenge for managers of urban tree resources. In these cases of urban horticulture, to decrease tree replacement frequency and ensuing costs, it is necessary to improve the establishment and maintenance of trees in cities. To develop urban horticulture, it is essential to educate all the city makers (landscape architects, civil engineers, urban planners, municipal officials and urban farmers) about optimal soil specifications expected for fertile urban soils: choice of organic matter nature, sources of organic matter or mineral material, proportions of organic matter in term of soil structuring and soil profile design.

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Multiple Trees Together Better Choice Than Multi-Budded Trees

Q. I lost two fruit trees this winter because of an irrigation problem. I would like to replace them with 4-in-1 pluot and plum tree. I’m hoping it’s not too late to plant. Two-in-one hole fruit trees…one Santa Rosa plum and pluot by reader.  A. It is not too late to plant fruit trees in containers but it is too late to plant them bare root or sold in packages. I am not a big fan of fruit trees that have more than one variety on the same tree. In a few years the more aggressive varieties dominate and kill the weaker varieties. In a very short time the tree is dominated by one or two varieties instead of four. I prefer separate trees planted very close to each other and managed as one tree. I would plant these trees about 12 to 18 inches apart; one on the east side of a large hole and the other on the west. In the case of pluots and plum, the plum tree should be a Santa Rosa which is a good pollinator for pluots. Pluots are self-pollinating in our climate but having a Santa Rosa plum tree close may help with fruit set and increase yield. Two rules should be followed when planting trees close together; never let them grow back into each other and keep them both pruned and trained to the same size.

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