To begin with, thanks to the very knowledgeable people on this forum who help us who are not, (in certain areas, anyway). Re: my Meyer Lemon Tree. I have a 1 1/2 year old tree which wintered in my unheated greenhouse (Langley, B.C.) During the winter its large pot was kept warm with heating wire wound around the pot and then surrounded with a pool cover (looks like sturdy bubble wrap). It survived and new growth is beginning to show. (unlike the Kaffir Lime tree which died!) My concerns are: yellow leaves, curling leaves, some leaves look like they have mildew under them, a couple had scale (until I picked it off) and a couple look like they have/had a bug tunneling or eating the leaves. I found a thin web on one of the branches but I don't see any red spider mites, but I have found a small normal looking spider on the branch. I have given it some water recently as it was watered very infrequently during the winter. Digging down into the soil it is damp but not soaked. So questions: Can I use a anti-mildew/fungicide on citrus trees? What about Safer's Insecticidal Soap? And has anyone tried Neem oil on Citrus? I have found no suggestions on the web that Neem would hurt the plant. However I did learn on an old post from 2006 on this site that fish fertilizer should not be used. Is this correct? Is my container too big? Should I down-pot it? Is it too early in the season (April 1) to fertilize? Should I add Epsom salts? Aggh. So many questions and so little knowledge, (and conflicted knowledge out there on the web!) Thanks for your help. Denise
There may been a slight nutritional deficiency. Have a look through the following document: A Guide to Citrus Nutritional Deficiency and Toxicity Identification. Unless there is a severe deficiency I would opt to do nothing other than ensure the tree is fed regularly during active growth periods using a fertilizer containing micronutrients. Insecticidal soap is effective for scale, spider mite, and aphid infestations. However multiple applications are needed to ensure that the pest's life cycle is broken. The tunneling damage is likely caused by leaf miners. The sooty mildew should disappear once the pests have been dealt with. Regarding epsom salts, have a look at this (.pdf) document. Regarding pot size, decide based on rootball size. There should be perhaps 1/2-3/4" of medium surrounding the rootball.
Dear Junglekeeper, Thanks for the info on Citrus. I may just look around for a Citrus specific fertilizer to get some micro nutrients into the soil. I have a Tropical mix which says it is ok for Citrus, but I'll keep watching for a more targeted one. As for the obvious problems I will hand pick any scale if I see any, and wipe off the mildew with an appropriate "cleaner". Have you any experience using Neem oil on Citrus or other plants? Denise
Two fertilizers readily available in our area are Miracle Gro 24-8-16 and Plant-Prod 30-10-10. Hand-picking scales would be ineffective without the sprays as those are only the adults, the ones you can easily see. Having said that the adults should be removed prior to spraying as the soap cannot penetrate the shell. I have no experience with neem sprays. Horticultural oils are reportedly more effective as it kills both adult and juvenile scale.
Junglekeeper, Thanks for the info. I intend to drop by Cedar Rim today to see if they have the Citrus fertilizer. Hopefully that will help a little. I'll also use Safer's Soap to douse the tree. Let's see where these two actions lead. dt