how often to water – Xtremehorticulture

Arizona Rosewood Is True Desert Native and Does Not Require Frequent Watering

Leave a Comment / desert plants, how much water, how often to water, when to irrigate / xtremehorticulture

Q. We have an Arizona Rosewood tree in our back yard. It is about 8 years old, is a double trunk tree with 4 inch circumferences on each trunk. It stands about 12 feet tall and is about 12 to 15 feet across. One water line presently waters it 3 times a day for a total of 30 minutes and is about 15 inches from the trunks. It has been fertilized with Miracle Grow tree and shrub fertilizer and has been treated for possible infestation of insects or grubs. We have noticed that some of the leaves have been turning brown and falling from the tree. Can you give some info on how many water lines it should have, what their locations should be and about how much water the tree should receive or what other problems we may be able to look for? A. This is the wrong irrigation schedule for Arizona Rosewood. This plant originates from the Sonoran Desert so it is a true desert plant. This means that it doesn’t like frequent amounts of water in small amounts as you are giving it. Normal for it would be watering not very often in the winter but giving it large amounts when you do and the same amount but more often in the summer. Yes, this is a bit vague but the watering schedule you have for it now is for nondesert plants. With this type of schedule it is possible that it is getting water too often. It is also possible it is not getting enough water when you do water. Hard to say. The problem now is that this tree is accustomed to frequent watering with small amounts. Its roots have grown to favor this method of watering. At this age, this tree may have some difficulty adjusting to a new watering schedule. One thing we can conclude is that it is a watering problem; either too often or not enough when you do water. It is definitely not a problem of watering too often AND too much combined. If you have never added drip emitters around this tree it may be time to do so. I am GUESSING it is not getting enough water when you are watering. Increase the amount of water by adding more drip emitters. This is better than increasing the minutes. If you increase the minutes then EVERYTHING on that cycle will get more water, whether they need it or not and it will waste water. It is less likely, but possible, that the roots of the tree are getting water too often. This can cause the roots to rot particularly for many desert plants. If I were there I would go out to Home Depot or Lowes and get an inexpensive moisture meter for houseplants. Bring it home and push it into the soil in several locations around the tree. Use this for deciding if the plant is getting enough water or not. Inexpensive houseplant moisture meter that you can use outside as well to see if the soil is moist or dry before watering. I posted this information sheet from Andrea Meckley previously.

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New Texas Ranger Not Looking Good After Daily Watering

Leave a Comment / dead, dying, how often to water, irrigate, rangers / xtremehorticulture

Q. I planted a Texas Ranger shrub three weeks ago in some sandy and rocky soil. I have been watering it with about two gallons daily. I added one inch-deep bark mulch in a 1 foot circle around the plant. Now I am finding yellow, brittle leaves on the lower stems and curling leaves on top. Am I overwatering? A. Yes, it is definitely watered too often. Overwatering can be in two forms; giving too much water OR giving water too often or both at the same time. “Giving too much water” relates to the number of gallons you give a plant each time you water. “Watering too often” relates to how many times in a week you give water to a plant. Texas ranger hedge sheared and consequently the flowers removed It is far more damaging if plants are watered too often rather than given too much in a single watering. Rangers do fine without wood mulch. They will benefit from it but they don’t really need it like other plants, such as roses and many fruit trees in the rose family, do. Now, a second problem. If wood mulch is in contact with young tender stems of plants, it can contribute to a disease called collar rot. Collar rot basically rots the trunk of the plant in contact with continuously wet mulch just above the soil surface. Collar rot of bean but the principles are the same. A third problem is just plain old root rot. This happens below ground and not at the soil surface. Root rot happens because the roots cannot “breathe” due to a lack of oxygen. The open spaces in the soil are continuously filled with water. Basically the roots “drown”. Bottom line; pull the mulch away from the trunk about a foot or eliminate it. Make sure the plant is planted at the correct depth in the soil. Make a basin around the plant about 2 feet in diameter and fill this basin with water from a hose or bucket. Set your drip emitters for twice a week during the summer. On the same days your drip emitters come on, fill the basin with water. This helps settle the soil around the root system. When you see new growth, eliminate the watering in the basin. Use only the drip emitters from that point forward. Use enough emitters to deliver 1 to 2 gallons each time you water. Next year, add one more emitter but leave the number of minutes unchanged. Fertilize once in January. Do not use a hedge shears to prune unless you intend it to be a hedge. If the plant is intended to stand alone, use selective pruning and remove one or two of the largest stems near the base of the plant every two to three years. A. Yes, it is definitely watered too much. Overwatering can be in two forms; given too much water OR giving water too often. It is far more damaging to plants to water them too often. Rangers do fine without wood mulch. They will benefit from it but don’t really need it. If wood mulch is in contact with young tender trunks or stems of plants, it can contribute to a disease called collar rot. This disease is in the soil and can spread into healthy tissue if the plant is stressed. The other concern is just plain old root rot. This happens because the roots cannot “breathe” due to a lack of oxygen to the roots. Basically the roots “drown”. Plant parts without light need oxygen. Plant parts that are green and exposed to light need carbon dioxide AND oxygen. Keeping the soil moist and having the wood mulch in contact with the trunk is a double whammy on this plant. If the soil is amended at the time of planting (University of Arizona discourages that) then you should water only about twice a week right now. We are in nearly the same climate zone. Bottom line….i hope it is not too late but pull the mulch away from the trunk about a foot or eliminate it. Make sure the plant is planted at the correct depth in the soil. Make a basin around the plant for the first few weeks and, in addition to your drip irrigation, water with a hose twice a week in the basin two feet in diameter surrounding the plant. This helps eliminate air pockets and settles the soil around plant roots. Actually you should be adding water to the planting hole when you are backfilling the hole with amended soil so the soil and water (mud) can flow around the plant roots. When you do this you will see air bubbles coming from the soil as the excess air is eliminated from the planting hole and around the roots. When finished planting, the plant should be solidly established in the hole. When you move the plant, it should not wiggle around in the soil. When you see new growth in a couple of weeks, eliminate the watering from the hose and go to emitters. Use enough emitters to give you 1-2 gallons each time you water. Next year, add another emitter. Fertilize once in January. Do not use a hedge shears to prune it but let it grow with little pruning.

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This Question on Drip Irrigation Made My Head Hurt!

Leave a Comment / drip irrigation, how many emitters, how often to water, how to irrigate, how to water / xtremehorticulture

Q. I have a LOT of different shrubs and trees on only 2 valves. I don’t know how to water them. The shrubs have 2 drip emitters for each shrub and they range from 2 each at 2gph (gallon per hour; gallon = 4 liters) for plants like photinia, red autumn sage, fountain grass, jasmine vines, rhaphiolepsis etc.; 2 each at 4gph for euonymous, abelias, boxwood, honeysuckle vines etc. The trees have more emitters. My landscaper told me to water 6 days per week for twice for 20 minutes each day (equals 4hrs/week). The nursery people advised me to water only 3 times each week for 45 minutes each day. Another nursery advised 6 days each week. So, what to do? My biggest problem is my 8 year old magnolia tree, trunk diameter about 5″, has 4 each a t 4gph emitters. It used to be very full, now it’s about 10 ‘ high; the leaves are dark brown, dry and falling off. All help would be appreciated. A. You even confused me! In their defense I would have to say it’s possible that all three could be right. Because plants are adaptable to different situations there can be several right answers to one irrigation question. Nurseries are there to provide service, the best answers they can muster up. I am an educator so let me take a stab at it from an educator’s point of view. I would like to give you enough information so you can solve your own problem with irrigation. But in my opinion, two valves are not enough to give you the flexibility of different watering schedules with all your plants and different microclimates. Bear with me on this. Let’s all agree for the most part that as plants get larger they will require more water. Let’s also agree that large plants will use more water, and considerably more water, than smaller plants. The larger the plant, the more water it needs and should receive. Three irrigation valves. They are basically on and off switches for water. Irrigation valves are basically an on and off switch for water; when the valve is open, water flows. When the valve is closed, water stops flowing. Since you have one valve in the front and one valve in the back, these switches open water to all of your plants in the front at the same time and the valve in the back does the same for plants in the back. There are three basic questions that must be answered when irrigating; 1) how long to water, 2) how much should be applied, and 3) when to apply it. The valves basically solve the question how long to water (on/off). Button type drip emitter Flag type drip emitter. The drip emitters solve the question about how much to water. An irrigation clock answers the question when/how often to water. The irrigation valves allow water to flow a length of time and the emitters determine the amount of water applied to each plant during that time. The length of time the valve is open combined with the size of the emitter determine the amount of water delivered to each plant. This is where the confusion begins. To make it as easy as possible to irrigate let’s hold one of these variables constant. Arbitrarily, let’s hold the length of time the irrigation valve is open: one hour. Just for the sake of argument. It could be 30 minutes, it could be 90 minutes, but let’s just hold it at 60 minutes. If we make this decision first, how many minutes to open the valves, it can make our other decisions much more simple. So we now agree the valve will be open for 60 minutes for our drip emitters. For me, this is a common length of time to leave the valve open for drip emitters. To determine how much water each plant will get we have to size our drip emitters; the gallons per hour we want to use. Because of plugging, it can be dangerous to give plants only one emitter. If that emitter plugs, chances are we will lose the plant in a short period of time during our extreme summer heat. Three different button drip emitters color coded for three different amounts of water per hour (gallons or liters per hour) To determine how much water to give the plant at each watering (or when the valve is on) we look at its size. The smaller plants of course require less every time the valve is on. So for the sake of argument let’s do this. Let’s give a plant 1 gallon of water every time the valve is open (in this case one hour) for every foot of its mature size. Example only! A very small plant may get 1 to 2 gallons. A medium-sized plant may get 3 to 6 gallons. A large shrub may get 8 to 15 gallon every time it’s watered. The larger the plant, the more emitters it will need under its canopy. A very small plant may require one to two emitters. A medium sized plant might require 3 to 4 emitters. A large shrub might require 6 to 8 emitters. So now you will take the number of gallons you are giving this plant and divide it by the number of emitters you will provide for each plant. When you do this, you will determine the number and size of the emitters you will give to each plant. So for instance a medium sized plant may get 3 to 6 gallons at each watering delivered by 3 to 4 emitters. So the size of the emitters might be 1 to 2 gallons per hour. But I would keep all the emitters going to one plant at the same size. It doesn’t make much difference if it’s one or 2 gallons more than you calculated. What is important is that you apply enough water during one irrigation to

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