On Assignment in Afghanistan

Me with a technician at field plots at Balkh University.

I am on assignment in northern Afghanistan now but my readers will still be able to follow the answers to my gardening questions here in the newspaper as well as my blog. I will post more on Afghanistan as well. I am at 36 degrees north latitude right now. Las Vegas is also at 36 degrees north latitude and at a similar elevation so the climates are very similar. I have been tracking the weather in Las Vegas and day and night temperatures are similar right now. Weather here is dry and the plots behind me are irrigated or it would be desert back there. So keep the questions coming!

Branches With Sharp Thorns Coming From Base of Orange Tree

Q. This year I noticed branches growing from the base of my orange tree and the branches have sharp thorns on them. Should they be pruned from the tree?

A. The branches growing from the base of your tree probably are shoots arising from the rootstock; common name, “suckers”. Let’s use your orange tree as an example but it could be other citrus as well such as limes, grapefruit, lemon, etc.

            Most citrus valued for their fruit are grafted to another citrus valued for its roots. This citrus valued for its roots is called the rootstock. The citrus plants used for rootstocks are selected for various characteristics but not for the quality of the fruit they produce. In fact fruit from rootstocks is nearly always pretty terrible.

            The rootstock may sometimes be more vigorous than the orange tree itself. The rootstock can send up shoots that, if not removed, may dwarf and overtake the orange part of the tree. Simply remove these undesirable suckers any time they appear and as close to the trunk as possible.

            They may sucker from the roots as well. Remove these too by cutting the sucker and the root with a sharp shovel and pull them from the soil. This eliminates the possibility that the rootstock will overtake the orange tree. Do not leave any stubs. These will easily regrow.

            Frequently in our climate tender citrus like some oranges, limes and others are killed during winter freezes. But because the rootstock part of the tree may be more cold tolerant it survives, then suckers and takes over.

            In a couple of years the rootstock is the only plant left and the owner wonders why the fruit is terrible and not anything like the citrus fruit he was expecting.

Orchard Watered with Greywater and Fertilizer Injector

Q. First off I want to thank you for the inspiration and motivation to get my backyard orchard project off of the ground. I planted 22 bareroot fruit trees this winter, 20 of which have budded out! I am still hopeful on the remaining 2.

            I have also installed a greywater drip irrigation system using the water from my laundry, the system I am using waters the whole 20'x30' orchard area rather than each individual tree. What I am curious about now is if I should utilize the surge tank in my system to apply any fertilizers or possibly something to combat the alkalinity of our native soil? I am noticing chlorosis (yellowing) already on the new trees this spring. Do I need to worry about that now?

A. Congratulations on your mini Orchard. Be careful with the type of laundry detergent that you are using in combination with your greywater system. Make sure it is biodegradable and plant friendly.

            You might want to do some checking on the state regulations on the use of greywater for irrigation. This would be overseen by the Nevada Division of Environmental Protection and much of that information should be online or a quick phone call away.
Nevada Division of Environmental Protection Website

            Using a fertilizer injection system is very convenient and adequate as long as your irrigation system is designed and installed well. If your irrigation system applies water evenly, then the fertilizer will be applied evenly as well. Make sure you incorporate a 150 mesh screen filter somewhere at the front of the system.

Mesh filter for drip irrigation paired with
pressure regulator

            The advantage of fertilizer injection systems are that they can apply small amounts of fertilizer continuously through the growing season (through most of August). It sounds like a fertilizer injector would apply more fertilizer than applying fertilizer by hand once in the spring but this is not necessarily so.

            Applying small amounts of fertilizer on a regular basis is much more efficient and can lead to significantly less fertilizer applied if you manage the irrigation system and very small amounts of fertilizer applied closely.

            You do not need to inject anything to combat alkalinity of the soil. Select acid forming fertilizers and use organic mulches. If you use organic mulch on the soil surface it will do a lot to improve the soil and combat alkalinity.

One brand of iron chelate EDDHA

            You could inject an iron chelate into your irrigation system to combat yellowing due to chlorosis provided the water is below a pH of 7.5. If you cannot guarantee this pH in your water then use the iron chelate EDDHA which is stable through the alkaline pH range. The other sources of iron fertilizers  are not stable under alkaline conditions and will drop their iron once they are put into water with a high pH.

            If you decide to inject fertilizers into your irrigation system then start the injection cycle after the water has been delivered to the plants for a few minutes. Water is not delivered evenly during the first few minutes of the drip irrigation cycle. Once the drip system is fully pressurized, well-designed drip systems then apply water evenly.

            Stop injecting fertilizer several minutes before the irrigation system shuts down. Several minutes of uninjected water will clean out the irrigation system of fertilizer that might be stuck in the irrigation lines.

            Water that remains in your irrigation system containing fertilizer will lead to the growth of algae and bacteria in your irrigation lines. Algae and bacteria are major culprits in plugging your irrigation system if you are using drip or even sprinklers.

Leave a Few Peaches to Enjoy on Young Peach Tree

Q. I don't know how old my peach tree is. I assume it's really young, like two or three years old because it is small. I am pinching off the small peach fruits leaving one small fruit every 4-6 inches along the branch. For this tree, that ends up being one to 2 peaches per branch, giving me overall maybe 10 peaches on this young tree.

A. Your thinning of the fruit sounds about right for the age of your tree. There are some people who pull all of the fruit off of a young tree hoping to get the tree into greater production beginning in its fourth year of growth.

            It doesn't really matter. I like to have a few fruit from young trees, an incentive for my labor. It won’t hurt the tree to have it produce fruit early.

            If your tree is really healthy and puts on a lot of new growth this and the following year then you should increase fruit production 300 to 400% over the next two years. You should be nearing full production by the fourth or fifth year if you are watering, fertilizing and pruning adequately.

            You will prune your tree in December or January. Look for my pruning videos on YouTube under the name of Extremehort. This should help a lot.

Is My Yellow Bells Dead from Winter Cold?

Q. Last year we planted a yellow bells plant. It appears to have died over winter. Do we need to trim it back to bring it "back to life", or just be patient and wait.

A. You should have seen it coming to life by now if it was not damaged heavily by winter cold. They can be cut back hard and they will come back if they appear dead but just have died back for the winter.

            They are a bit tender and in the wrong spot they will freeze out due to winter cold. If this was the case you might find a warmer microclimate in the yard and replant and pick a different plant for that spot.

I want to see what yellow bells looks like

            They can get ten feet tall and three feet wide just so that you remember to give them enough room. If it freezes back each year but comes back in the spring it will never get that big or if it does just keep it cut back during the winter.