brown needles – Xtremehorticulture

Watering Pine Trees – Water Deep!

2 Comments / Aleppo Pine, brown needles, dieback, Pine tree / xtremehorticulture

Q. I recently moved into a condo that has pine trees on the property. Some of them look like they aren’t growing much but those still in grassy areas look much better. Some other pines have branches that are dying back. Do I need to supply water to these trees? The very new growth in the spring of pine trees are called “candles” because they look like candles. All the new growth for that pine tree is contained in that candle. If water is available to the tree, candles will stretch and get big. If water is limited, the candles will not stretch and the new growth will stay small.Notice the buds at the base of the candle. I will talk about these buds in the next picture. A. All of this is not simply a water issue. There is probably a disease problem going on as well. But first things first. Pine tree branch growth, and how dense the tree is, has a lot to do with how much water it receives in the spring and early summer months. Just as important is how deep the water drains in the soil, to encourage deep root growth, after it’s applied. Branches of pine trees are in the whorls along the trunk. In the picture above, you can see the buds at the base of a candle. Those buds will grow into limbs that are in whorls around the trunk. Most native pine trees grow along canyons or stream banks where water is plentiful in the spring months and less available later in the season. Water availability coincides with spring growth which in turn increases the tree density. Water pine trees deeply, particularly in the spring months. How deep? Water should drain 24 to 36 inches into the soil each time it’s watered. To make sure it’s deep enough, measure this depth with a long thin metal rod like a piece of rebar. Plenty of water this time of year helps push new growth. This new growth supports the needles responsible for a dense tree canopy. Deep irrigations are important later in the year, but less often, to maintain this density. This blow over can happen to trees when they receive shallow irrigations and shallow applications of water. This is a mesquite but it can happen to pine trees, and does. Water large trees deeply to avoid blow over during strong winds. With deep irrigations, roots will grow deeply. Lawn watering only applies water about eight or 10 inches deep. This is not deep enough for large pine trees as they get bigger. Watering lawns with shallow irrigation may keep the trees denser but it doesn’t encourage the deep roots needed during strong windstorms. Besides the lawn water, large pine trees should get periodic deep watering as well. Pine trees in lawns may look full but they usually will blow over during windstorms as they get bigger. Aleppo Pine Blight is classified as a disease but there is no known pathogen or living disease agent associated with it. In extreme cases it can cause entire branches to die. But the tree with this problem should be and Aleppo Pine, not a different type of pine. Branch dieback of pine trees is usually a physiological disease that cannot be cured called Aleppo Pine Blight. In most cases, new pine needles in the spring replace the dead needles lost during the winter months.

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One of Several Pine Trees Sparse and Scrawny

Q. Why does my one pine tree seem so sparse and inadequate? I purchased four Mondale pines and treat them all equally. But one of them looks so scrawny. The other one shown looks healthy and appears to be robust. Any thoughts on that? A. The usual reason for a pine tree being sparse and not full is that it is not receiving the same treatment as the others. Pine trees generally maintain needles on their branches until the wood gets to be three to five years old and then the needles are dropped from the older wood. This older branch is needle-less except for small branches growing from it less than five years old. The reason for canopy thinning is the loss of needles at a higher rate than they are being replaced. So bottom line for a pine tree becoming sparse is that the tree is not putting on enough new growth. Reasons for this include a lack of water, fertilizer, damage to the tree, or less likely, diseases or insects. Pine needle brown dieback due to lack of water By far the most common reason is that the amount of applied water is not enough. So when you say you treat them the same it does not necessarily mean these treatments are all reaching the trees equally. But if there is inadequate water two things will happen; the tree will put on less growth and the needles will begin dying back from the tips. The first thing to do is to check and make sure that whatever is delivering water to the tree is not plugged. Secondly, make sure that water is not running off the surface to some other location. Just because water is applied to a tree does not mean it is getting to the roots. Circling roots of semi mature tree due to circling roots in the containers Remember, that as trees get bigger their demand for water increases. The increase is not simply a few gallons per year but is much greater because trees are three dimensional in their water use unlike a lawn. Unlike a lawn, when a tree doubles in size its need for water more than doubles. The next most common reason is that the roots of the tree never fully established into the surrounding soil after planting. This can be because the tree was too old for the container and the roots started circling and never established into the landscape successfully. It can also be because the tree was not firmly staked at the time of planting. Correctly staking a tree will immobilize the roots and help them to establish successfully into the surrounding soil. You should be able to push on the trunk and NOT see any movement of soil at the base of the trunk. The next most common reason is damage to the roots or trunk. This will be far less likely than a watering problem but much easier to identify. This can be physical damage like construction, damage from chemicals like salts or weed killers, insect or diseases like collar rot. If the tree is being shaded by other plants and not receiving enough light (at least six hours a day) then these branches in the shade can drop their needles. If this is the case then some pruning to allow more light will help. If they are planted too close together then consider removing trees so the remaining trees will thrive.