Matt, what did you use to rid scale? Baby shampoo or a chemical insecticide? Chemicals are dangerous. Especially if used indoors. Since you're in NY, you either sprayed inside or hauled outdoors to apply..Or did you use systemic? I once killed a Gardenia tree by using a harsh chemical, even though, the tree was outside, and I followed directions to a T. Ironically, branches blackenedd and tree died..Not from scale, but the chemical itself, since it died the day after applying insecticide. I spray citrus with Fish Emulsion, in autumn, before bringing indoors..FE prevents and kills scale on contact. If you find Fish Emulsion replusive, (it has a fishy smell that lasts about 2 days, but they now sell an odorless type) there are other oils such as Neem. Artificial light will certainly help, but in your case, I doubt low light is/was the cause of your lemon's problems. Stop fertilizing..For one thing, as you stated, light is low..Citrus go into a semi-dormancy..They need a rest period..If light is low, plants slow down, therefore, adding fertilizer can cause spindly growth. Also, when a plant is undergoing problems, disease/insects, it is advised to stop adding fertilizer. If anything, in early fall, add a slow-release, low NPK type. In spring, or when growth is spotted, start your regular feeding program. I disagree the Baby Shampoo did any damage. How much did you use, and what ratio of water? One author and tv host, Jerry Baker, recommends cleaning foliage with baby shampoo.. Did you discard the Ficus? Considering it's a bonsai, scale shouldn't be too difficult ridding. For starters, you can hand-pick, unless you're squeamish about bugs..Matt, you're talking to a 'bugophobic,' lol, yet, if I saw scale on a plant, you'd best believe I'd start plucking, though spraying is preferable..lol Prune blackened branches..they will not resort to green. Shake plant to remove dead leaves..Toss leaves in the trash, or burn..which reminds me..if you have other plants, especially neighboring, inspect each carefully..also, isolate plants with scale. Move plants to a cool,(65-68F is fine) airy, humid location..and yes, humidifers help big time..fresh air is also important. If you have a ceiling fan, run on low at least 1 hour a day..it circulates air to a degree. I also use a rotating fan. Matt, do you have a picture to post? If your citrus is managable size, after removing dead leaves, haul to sink or shower, allow water wash leaves..2-4 mins. Hose Ficus too. Matt, I'm an optimist when it comes to plants..only plants, but plants, nonetheless..Some of my plants were bought in what I coined, the 'dead cart' in stores where plants were going to be tossed..In and outdoor plants..I'd never buy an infested plant, no Sir, I'm not that optimistic..lol.. Good luck, Toni If you have any questions, ask away..Please stop fertilizing, and before adding water, check soil, make sure it's dry before giving a drink.

islandmanmitch: The tree was purchased last year as 2/3 years old. It has been watered daily and has excellent drainage. There are temperature changes--never below 50F and never above 90F, though. The tree looks healthy with lots of dark green leaves. There was, however, some yellowing and loss of older leaves over the winter. Any ideas?

Take a paper/plastic cup and punch a small hole in the bottom. Fill it with your mix and then put your finger over the hole while you fill with water. Remove your finger from the hole and leave it to drain. The perched water will remain. You can see it if you have used a clear plastic cup. Insert a toothpick into the hole. The perched water will drain out. The toothpick acts as a wick and will demonstrate why you generally need a wick in anything other than gritty mix. This test will show you how much perched water your mix retains but bear in mind it will hold more over time as the mix degrades. Organic mixes will degrade faster. I use a mix similar to the one you are considering in pots that I expect to last a year or so before re-potting or planting. Just buy a rayon mop and use a few strands to make a wick. Tie a knot to keep it from falling through the screen that you use over the drain hole. I put about 4" of mix in the bottom while holding the wick vertically. You can find pictures in Al's thread on water movement in container soils, which you should read carefully. It has lots of great info but bear in mind they are mostly talking about wetter parts of the country. If you buy the typical nursery citrus in heavy organic mix, I would remove all the loose parts. After setting the loosened rootball on the mix and confirming planting height, I usually add a bit of mix at a time and use the Dramm Water Breaker nozzle on my hose to gently loosen the roots and let the nursery mix and the new planting mix combine. You want to avoid any sharp changes in potting mix. This is the opposite of just plopping the plant in the pot and filling it up with planting mix. This post was edited by GregBradley on Fri, Oct 11, 13 at 11:57

Gardengal's addition of genetics into the conversation reminds me....the reason redwood....or to a lesser but still impressive extent, an eastern white pine or a Norway spruce gets so tall is duration of main growth event. So, to take things in the opposite direction, a flowering crab will never be 100 ft. tall. The genetics of the plant don't allow for the rapid type of growth required in trees that eventually will attain great height. At the same time, the crab's growth will slow once it reaches its 20 or so ft., cultivar-dependent. A coast redwood has the fast growth of youth, but is able to maintain this growth rate far, far into its lifespan. That's how we end up with these very tall trees. They maintain "youthful vigor" long into their lives, growing at rates similar to very young plants. In fact, for a while, people with hidden agendas were talking about how old-growth forests were a "waste" of resources because they aren't growing, are not storing carbon ( as if these people care about such matters) like young forest do, blah blah.....Meanwhile, actual research has shown the opposite; Old-growth forests continue to store carbon-in other words, continue to grow- and in fact store more carbon than an equivalent patch of young forest or plantation. So what I'm rambling about this time is, trees' size is ultimately determined by genetic potential and an environment which meets its needs, the genetic factor allowing for an extended period of growth. But tailoring an answer to some landscape cultivar is obscure in the extreme. Plus, we can't really allow for happenstance; Who knows what might befall a plant in the landscape somewhere? Is next year going to be dry? Who knows? Is another Sandy-like storm coming to the east coast? Beats me. We can provide generalities, but all of the stuff discussed in a forum like this is subject to randomness. It's pretty hard to pin down that tightly.