Attached are some photos of my Kishu Mandarin. We have had this plant potted for about a year or so. It has been doing fine on our patio in San Diego. The weather for August and September has been unusually hot and humid at the coast. The Kishu was near the lawn sprinklers and was getting a small amount of water from that source. We would unregularly water the potted plant. It has been fertilized in the past. As you can tell the leaves are turning brown from the ends and curling. There are few leaves remaining on the tree. It has many small mandarins that are holding well. The stress of the fruit may be a problem but we are concerned about the leaf changes. One branch has a small white bud on it. It has been recently watered well. Our water meter indicates it is wet. Help ! Mousemaster in San Diego
When was the last time you flushed out the container? This tree shows symptoms of a toxic level of soluble salts in the growth medium (potting soil). Flush out the medium with clean clear water in the amount of 4 times the volume of the container. The root zone of a containerized citrus tree, needs to be completely flushed 3 or 4 times a year. Lastly a Seedless Kishu is a beautiful citrus variety, and a variety that requires a lot of nutrition. Fertilize your tree at a very minimum of once a month, twice a month would be much more beneficial. Lastly, DO NOT water the Kishu using a lawn sprinkler. Take care of your tree's needs yourself. This tree looks to have be neglected. Good luck to you and this tree. - Millet (1,207-)
I am not familiar with the idea of flushing out the container. Do you mean take the tree out first and then rinse the terracotta pot? Or Do you mean I should run large amounts of water through the pot with the tree in it? Thank you for your reply. I will step up the fertilizer. Mousemaster
Every time a container citrus tree is watered, enough water should be poured into the container so that approximately 20 percent of the water drains out the bottom. This reduces the build up of soluble salts in the medium. Many people are afraid of damaging their tree by over watering, therefore do not water thoroughly enough. When you water the tree water it well. By flushing out the container, I mean run the water through the growth medium (through the root system with the tree still in the container), so that the salts in the medium will be flushed out. With the condition the tree is now in, you should see some improvement in 2 to 4 weeks, if you fertilize the tree once every two weeks. ALWAYS, use a fertilizer that also contains trace minerals. Dissolve 1 teaspoon of magnesium sulfate (Epsom Salts) in a gallon of WARM water and apply the solution to the trees root system once every 3 months. The best to you and your tree. - Millet (1,207-)
Thank you for your clarification. I will begin the process of watering as you described. Approximately how often should a citrus in a pot be watered? I was trying to target twice per week. Is that too much? Mousemaster
You shouldn't water it to a schedule - rather, you should water it thoroughly when the top 2 inches or so of the soil is dry. Make sure all the water drains from the bottom of the pot.
Actually watering citrus gets blamed way to much for causing trouble, when the actual trouble maker is the porosity and the density of the growth medium. For mediums having excellent drainage and high air porosity, like CHC/peat moss mediums, the tree could be watered 15 times a day without any trouble at all. It is almost impossible to over water a CHC medium. Remember, it is not the amount of water that causes problems, it is the lack of soil oxygen that does the damage. It is true that in aged mediums, and medium that do not have good air porosity, over watering can cause problems. and over time even kill the tree. This is due to the high level of water remaining in the root zone and not draining out fast enough. When this condition exists, the air pours in the medium are filled with water and the oxygen is driven out. What actually damages the tree, is not the amount of water, but the elimination of oxygen from the medium. The tree is killed by suffocation. Further, in these types of mediums, the CO2 (released by the roots) cannot filter out of the root zone, and therefore builds up to toxic levels, thus causing additional damage. For root zones with rapid draining, high air porosity, water never ever cause a problem. For growth mediums that do not have adequate drainage, and therefore lower air pours, Morbius's advice is certainly correct, and should not be watered until it dries down, so that the roots can utilize what oxygen is available to them. - Millet (1,206-)
The plant continues to do poorly. My wife has the green thumb and would like to re-pot the plant. Can you suggest a potting mix or other medium for us to use? Also, we are thinking of layering a small amount of rocks (polished river rocks) in the bottom to assist with the drainage. Since the photos, many of the fruit are now yellow and shriveling. The last few remaining leaves are discolored and dropping. We don't want to loose this tree so any final suggestions are welcome. Mousemaster
I would recommend either a CHC medium or a bark based medium. You can find tons of information on both of these mediums on this forum. Putting rocks or any other aggregate in the bottom of a container does not increase drainage, it actually decreases drainage. This is due to the perched water table, found in the bottom of every container. The addition of rocks raises the perched water table higher into the container, causing problems. Not a good idea. You can find a lot of information on the Internet concerning perched water table. - Millet (1-204-)
Mousemaster, if you decide to go with Millet's suggestion of chc (which I highly recommend by the way) and you only have a few trees or less, you can go to your local pet store and find chc in small amounts as a terrarium substrate. That's what I did for my two trees and it has worked out great. Just soak the chc overnight with a tablespoon of epsom salt and mix it either 3 or 4 parts chc to 1 part peat moss. Either of the following are fine but you get more for your money with the compressed brick... http://www.petsmart.com/product/ind...-2484-DE11-B712-001422107090&mr:referralID=NA http://www.petsmart.com/product/index.jsp?productId=2752434&keepsr=0&clickid=prod_cs
