I was going to post these separately but since they are both leaf and citrus related, I will combine the question. I have recently purchased a new Key Lime Tree and have potted it. John Heider, you gave me some excellent tips on potting a citrus tree. Now I am seeing some curling on some of the leaf edges and some which have also turned brown. Some of them have turned brown to the point they have shriveled up. I have a picture but I don't see a place to post it here.

My second example is my Meyers Lemon which has recovered from a bad case of leaf miners and a brush with death after the freeze last year. I thought it was a definite goner and had prepared to dump it out when I noticed new buds in the last two weeks! It has been potted for the entire 5 yrs of its life. However, the leaves while leaf miner free, are splotched greenish-yellow. Is this a nutrient issue? Should I repot with buds present? Thank you and I hope I have not replicated this question from previous discussions.

Answer #3 · Maple Tree's Answer · Kristal-Other than the yellowing the leaves don't appear to be affected by insects or disease. It looks as though there is a nutrient deficiency. Veins still green with most of the yellowing starting at the leaf margins would indicate a magnesium definciency. As the deficiency gets worse the yellow area gradually enlarge until the entire leaf becomes yellow. Other deficiencies can look similar in appearance other than a nitrogen deficiency that will normally be indicated by the central vein turning yellow also. I would first purchase a soil pH test kit and test the soil. Soil too acidic, soil pH below 5, or too alkaline a soil above 7.0 can affect the ability of the plant to take up certain needed nutrients. Once the soil pH is known it can be corrected using dolomite lime or sulfer to raise or lower the pH as needed at the same time add the magnesium needed to hopefully correct the problem. Most of the soil test kits will also test for any nitrogen, phosphorus, or potassium deficiencies which can help in knowing your gardens nutrient needs.
Again, too much water can also add to the yellowing of leaves. Make sure the soil is well draining and the tree isn't watered too much. A slow deep soaking of the soil once a week is usually enough for my tree in the summer and is much better than several shallow waterings.

If the soil is draining well and the roots don't appear to be circling around the pot or growing out the bottom you may want to wait with any transplanting or potting up at this time of year. If you haven't fertilized the tree this year I would fertilize with a good fertilizer formulated for citrus trees. Citrus trees are heavy feeders and like fertilizers with a higher percentage of nitrogen than that of phosphorus and potash. Ferilizers with micro-nutrients in them such as magnesium, manganese, iron, copper, zinc,and boron should be used. I found the fertilizers noted for citrus most of the time will include these nutrients. There a several good citrus fertilizers. I use Vigoro Citrus and Avocado food which seems to work well and has a higher percentage of the micro-mutients than others I have found. This is a slow release fertilizer that will continually fertilize for several months at a time. Some give their citrus trees a dose of Epson Salts at times which is the Magnesium they need to keep the leaves from yellowing if there might be a deficiency.

The key Lime has good coloring but with the little curling and browning of a few of the new leaf tips it could be getting too much water. With it being so young and newly planted just make sure the soil is moist but never too wet or dry. Just keep an eye out for any changes. I think once it becomes more acclimated to its new invironment all will be fine. I wouldn't do any fertilizing of this tree during its first growing season. Forcing new growth can sometimes add to a trees stress when trying to acclimate itself while becoming more established.

Watering schedules may be somewhat different in the greenhouse than outdoors. Normally the greenhouse will have a more humid environment which may cut the use of water down somewhat. I have spent some time in Florida and can't believe anything could be more humid than the outdoors but I guess it can. I would do any watering in the greenhouse early in the morning so that additional moisture isn't added late in the day. This will give time for much of the moisture to dry before evening. Citrus are susceptable to fungal diseases therefore any additional moisture sitting on the leaves for a period of time could be a problem. If the greenhouse has some venting I would open the vents at least for a period of time each day to allow for some air circulation.

http://www.gardenality.com/Articles/984/How-To-Info/Growing-Basics/What-Is-Soil-pH-And-How-To-Test-And-Adjust-It/default.html

Let me know what you find if you test the soils pH. After fertilizing let me know if there is an indication the yellowing is getting better.

John)

Answer #1 · Maple Tree's Answer · Hi Kristal-Sorry to hear your newly planted lime isn't looking as it did when you planted it. Many times after planting a new citrus tree I have had small problems during their first growing season. Some transplant shock or just acclimating themselves to a new location seems to set them back. After their first growing season the have always then been fine. Environmental changes such as amount of light, temperatures, amount of water, etc. seems to affect them until they acclimate themselves to the differences. Some times it is difficult to distinguish disease from harmless environmental conditions. The leaves curling and browning is usually caused by too much water or cool temperatures. Cooler than normal temperatures can cause the tissue in the leaves to dry out which will leave a burnt appearance or browning of the leaves. Too much water can also cause the tips and margins of the leaves to turn brown. I'm thinking this may be the case if there are no yellow or brown spotting of the leaves. This could indicate fungal or other disease. Yellowing of the leaves with the veins still green would indicate a nutrient deficiency. With the plant looking nice when purchased and recently planted I would assume it would take some more time for most disease or nutrient deficiency to show up in the leaves. Make sure the soil is not staying to wet. I would hold back on the watering and see if this doesn't help the trees appearance. If you could upload a picture it may help to identify the problem also. Above this answer and to the right of your name below your question you will see where you can upload any picture you have saved on your computer. You should see 'Edit Your Question' and 'Upload A Picture'. Just click on the 'Upload A Picture'.

A close up picture of an affected Meyers Lemon leaf would help to identify the problem. If the leaves are green with yellow spotting does this yellowing look like hallos around a brown or black spot? Are the leaves yellowing with the leaf veins staying green? Is there a difference in the spotting of the older leaves compared to the newer growth. If the tree has been in a pot for 5 years and never been potted up it could be root bound. In this case there could be a nutrient deficiency when roots are unable to absorb the nutrients they need. The soil pH factor can also affect the amount of certain nutrients the plant may not be able to absorb. Lets see what the picture of the tree looks like first.

John)