Proper care and feeding of a lemon tree.

 On my walk this morning I noticed a sign above the little lemon bush. 

"This is a LEMON Tree Do NOT pick the Lemons until they are Yellow and please leave some for ALL the neighbors. DO NOT water the lemon tree untill the END of August! Someone has been overwatering it."

 

I have not 'watered' it per se but when I go to turn off the hose I drop it on the tree and then go turn off the water. All of maybe 20 seconds. The tree was showing signs of stress when I first saw it.

Right... so here I go on a plant rant. Might even put up my own info sign.

First: they are growing a tropical tree in sandy clay soil with no nutrients and seemingly no amendments. Hard to say when it was last fed with proper citrus food. It cannot take up the proper nutrients with our crappy clay alkaline soil.  The drainage is fine, nutrient level not so much. Chemical reasons have to do with

Second; it has recently flowered and put on fruit. When trees, especially citrus, put on fruit they sacrifice nutrients to feed the baby fruit, thus the leaves begin to turn yellow around the edges. It is very hungry! It needs food dangit!

Third: occasional watering as I was doing is not going to cause an issue given the type of soil we have. Apparently they saw the hose laying in the bush and thought someone had actually watered it. Also the wall behind the tree is wet, there are still open sprinklers in the area and they just watered this morning. And the day before yesterday...they are on a three day a week schedule due to the weather and are now watering the lawns regularly.

So, it seems to be an established bush which means in it's current situation watering every two weeks or so is not bad. They have surface roots and is currently shading those roots with it's own canopy so the core root ball is staying sufficiently moist. When I was looking at the other 'mint bed' I noticed a tiny pea sized lemon that was yellow. So help me if someone thought they could plant that I'm going to go on a definite rant. 

'Overwatering' could be the culprit as could happen in a larger tree, more than likely it is starving though. I have encountered (previously mentioned) customers who thought they shouldn't feed a plant when it is flowering or fruiting. What? You going to starve a pregnant mother because she might get fat? Heck no! People don't understand that is when you need to feed them even more so (but not overfeed).

I will have to put a sign up asking questions and maybe leave my number for further information. I can understand how they would get the idea of not watering it for three months being an established tree. Someone may have told them that was a good schedule for it but if they are not feeding it on a regular schedule with proper food, that is the key problem. I think I will take the more subtle approach and buy a bag of citrus food and leave it in the community patio along with some veggie seedlings or seeds. (Thank you Margaret for the seeds when they get here!)

My planting area is still very dark from the watering yesterday afternoon. Very happy about that and shows that late afternoon watering is best for my situation. It's approximately three days between waterings currently and could be pushed to four depending on the weather. Anxiously waiting for more planting material and I think I need to come up with a sign for my bed(s) to let people know who to talk to if there are any problems or need advice.

Citrus (and other fruit) trees are usually fed about three or four times a year depending on the food you use.  Early spring, mid summer and fall depending on the weather you could even feed it early winter. Due to an insect that has invaded the US and San Diego more so called the citrus leafminer, I have normally told people to hold off feeding until late spring or summer if they feed in the fall. 

Leafminers attack the new leaves and shoots of citrus, their life cycle is keyed to that timing. Luckily this tree shows absolutely no signs of that insect likely because it is isolated from other trees and not in an open area. Remember the citrus swallowtail I mentioned as pollinators?

Those two are completely separate issues. The 'bird poop' is actually the caterpillar of the Swallowtail butterfly, effective camouflage right? Bird Poop caterpillar is the other name for it and it can be as devastating as the leafminer.

Adult small silver moth with a wingspan of 4 mm. TINY!

 

Leafminer can be mostly cosmetic damage on a larger tree but it should be nipped in the bud...aha...see what I did there? Moving on.... Do not pull the leaves off if they still have 75-80 percent green left. Any green will help the tree more than not having at all. In the upper left end of that snaky trail you can see a yellowish color, that is actually where the larva has paused. If you find this on your tree, simple solution is squish it. Yes... use your fingers and simply pinch the area and that will kill it I gaurantee it. In San Diego the damage usually starts around June sometimes before so that means the adults are out in April and May. There are Citrus Leaf Miner traps (CLM for short) you can buy at a nursery/garden center. Not sold in big box stores! In San Diego they can be put out any time of year but spring is best.

There is also a systemic that is safe for use on citrus. If you want to go totally organic, not much is going to help. The caterpillar is up to you, leafminer you can use BioAdvanced (formerly Bayer) Fruit Tree and Vegetable Systemic Insect Control. Look for the blue bottle BUT Make sure it says Fruit Tree! The other version is for ornamentals only and a higher concentration. This is a once a year dose and you would not be able to eat any of the fruit for over a year to be safe. I have had a few customers say, 'I don't really eat the fruit' oh heck you don't, but what about any other incidental consumption? It's not going to kill you technically but it can make you sick. The active ingredient is the same thing that is in Advantage flea control for dogs and cats. So if you or your pets have had sensitivity or a reaction to it, don't use it.

The organic treatment is another one I've mentioned, Captain Jacks Deadbug Brew which will definitely take care of the caterpillars (you can use BT for them as well) but it will help to a degree with the leafminer. It is a soil bacteria that when ingested by an insect infects their gut and causes them to stop eating and die. It is harmless to humans and other mammals but as most organic controls it doesn't work as effectively. Just pick the leaves off if they are horrendously damaged and squish the bugs as you see them.

So that's my rant/topic for today. Don't panic about every little blemish you see on your plants, note them down, take pictures, see if they get worse, do what needs to be done. Talk to me, I'm happy to help!