Question
QUESTION: Hi,
I have a 1 year old improved Meyer Lemon tree that had originally came with aphids and scales so I washed the tree down every few days with insecticidal soap. That got rid of the bugs but left white residue on the top of the soil afterwards. I didn't think too much about it but recently, leaves that looked very healthy, full and green  began to fall. They're falling without the stem. Now the leaves that are falling have brown dry-ish tips. I have branches that are just nude now.
I researched online and some say that it's a salt buildup but I'm not sure.
Also, I have another meyer lemon tree that is kept together with the sick lemon tree and that one hasn't had any issues at all.
The sick lemon tree has some gnats or fruit flies around it. The fruit flies will only come out like..2-5 at a time. Then they go away for a few days - a week. Then I water and they come right back. Could they be damaging the roots?

Thanks for your help!

~ Liz

ANSWER: Hi Liz, I have no idea where you live, what are  you are watering your plants with? Is it in the ground or in a pot?  If so, did you move it up or is it in the same pot?  kathy

---------- FOLLOW-UP ----------

QUESTION: Hi Kathy,
I'm located in New Jersey. I just got the plants about a month ago and repotted them a week after I got them (according to the seller's direction) to 8x8 inch pots and have kept them indoors since.
I've been watering my plants with tap water. Also, they get around 12 hours of sunlight.
Thanks!
~ Liz

ANSWER: Hi Liz, I am originally from Clark, NJ and now have my nursery in Sarasota, FL.   If you plants have water in the bottom of the pot dish you must remove the water after 15 minutes or you will rot your plant.  I would use Pure Neem Oil by Dyan Gro which is organic and does not wash off for your pests.  Remember when you water in the pot that the plant dries from the outside in.  Sometimes just watering the outside edge instead of the whole pot until it roots out so you do not rot it.  The tips being brown could be fertilizer burn, make sure you use a slow release fertilizer for your plants so this does not happen.  kathy

---------- FOLLOW-UP ----------

QUESTION: Hi Kathy,
I water in the sink and leave the plants in the sink to drain for 30 minutes, but it does take a week and a half to two weeks before the moisture meter indicates 50% moisture. (That was what I was told to look for before watering again.) I haven't used any fertilizer since I just repotted (with a 1/3 mixture of aspen chips with 2/3 garden soil).
I will definitely try watering just the outside edge. How often should I water the entire pot then and how long would it take until the plant roots out?
So you definitely think that it is overwatering and not the gnats or the residue from the insecticidal soap?
Thanks so much!
~ Liz

Answer
Hi Liz, Well the bugs do play a part in hurting the plant.  Usually they are sucking bugs that leave yellow spots on the leaves or suck the juices out of the stems.  Brown or black tips is usually fertilizer burn or over watering.  Yellow leave falling off not enough water or they are shedding leaves to make room for fruit and flowers.  Use your water meter close to the plant and then try it on the outside edge see if it tells you the difference.  When the outside edge is dry water the edge.  If the inner part gets low water the whole plant.  Hope that helps.  kathy