It's a fun project to sprout and grow your own avocado. 

We wouldn't keep spraying it with neem. That could be causing some of the leaf spotting/burn (phytotoxicity). Pesticides should be a last resort and used only when you know what pest you are treating for. Oftentimes issues are caused by environmental conditions not related to insects, or damage was done long before, as in when it was outdoors.

Are you seeing new holes now? Flip the leaves and carefully examine the undersides and other parts of the plant. Holes would suggest old damage or that a caterpillar-type insect came in with you. It could be easily hand-picked off.

Give the plant the brightest light you can (they need full sun), and give it some houseplant fertilizer, which should help it green up a bit. Gently sponge the leaves of the plant with warm water  or you can even set it in the shower for watering occassionally.

Christine

Caterpillars, crickets, snails/slugs, and other leaf-chewing critters can hide-out elsewhere during the day and feed at night, so you could try looking over the foliage after dark or before dawn (whichever is more convenient). Hiding spots probably include under the pot's base (possibly just inside the drainage holes) or under a rim if this container style has a rim which rolls over and creates a lip with a gap underneath. Without seeing the culprit in action, we cannot recommend any particular pesticide which will prevent it from causing more damage; not all pesticides impact all pests equally effectively. (Plus, if it is found, the simplest solution would be to physically remove it anyway, rather than using insecticides.) For now, the damage is not serious and the rest of the damaged leaf is capable of photosynthesizing to continue fueling the plant's growth, so we don't recommend removing them. (If they fall on their own later, that's ok.)

While tropical plants spending the winter indoors normally don't need fertilizer, in this case, we suggest using a dose (as per label instructions for dilution rate) of a fertilizer formulation for houseplants. Look for a brand with micronutrients, which are the elements listed on the label beyond just the common N-P-K. Cicada breakdown can be a good source of mild, slow-release natural fertilizer, but is only practical to rely on outdoors, as soil microbes and other soil life are responsible for breaking that organic matter down into byproducts the plant's roots can absorb. While houseplant soil isn't sterile, it may not have enough of (or the right kind of) soil microbes needed to do this, and so the dead cicadas aren't a reliable source of nutrients in this case. You don't have to remove them, but a single dose of supplemental fertilizer may help boost the plant's vigor, even if it doesn't stimulate any obvious above-ground growth.

Few leaf-chewing pests actually live in the soil. While various contaminants (so to speak) could have been in the soil stored in the shed, it's probably not a problem. Unless the plant is rootbound or the soil is not draining well, you can wait to repot until spring or later. If drainage does need improving - if the soil stays too wet and takes too long to dry out - then you can replace it at any time.

The plant appears to be in decent condition for now. Leaf damage does not heal itself, but as long as it isn't worsening significantly, mildly damaged leaves are not a major concern. Many tropical plants merely "hang on" during winter while indoors, tolerating the reduced light and drier air, and don't grow much until spring days become long enough again that they can collect enough light energy to produce new growth. This is fine and can be treated as a type of dormancy, in that plants may stagnate but don't decline.

Make sure you're checking the soil for moisture before watering so the roots don't stay too wet; root rot is a common cause of plant dieback or decline indoors. Feel the soil at least an inch or two beneath the surface; if dry, the pot can be watered well; if moist, wait longer before watering so the roots have time to "breathe." Similarly, make sure any saucer used under the pot's drain holes is emptied as soon as it's collected drained water so the soil doesn't soak it back up and stay too soggy. While this is unrelated to the holes in the leaves, it can contribute to symptoms of off-color foliage (typically yellower than normal) and premature leaf shed as ailing roots fail to absorb the nutrients they need from the soil.

Miri

Leaf browning/crisping can occur for a variety of reasons. For example, it's possible:

• the ambient humidity of the room is too low
• temperature changes from a nearby drafty window or heat vent that blows onto the foliage (this ties-in with humidity levels)
• the soil is staying too wet (this causes root suffocation, and when roots can't function well, they can't keep the leaves hydrated, despite the irony of the soil being plenty moist)
• the plant is shedding older and/or previously-damaged leaves (leaves in the process of dying naturally tend to dry out)
• phytotoxicity (as Christine mentioned, pesticides can sometimes damage plant tissues, even when applied as the label directs)
• insufficient light, which results in leaf drop of older growth as plants adjust to their new environment after being outside for the summer (this process can take weeks or months after a plant comes in, because growth processes have slowed down); as described above, leaves in the process of dying tend to dry out

You can clip this single leaf off since the brown areas are fairly extensive. Otherwise, the leaf will fall off on its own soon enough.

If the soil is staying constantly moist, make sure the top inch or two is getting fairly dry before giving the pot another thorough watering. Deeper soil layers take longer to dry out than the surface, so roots growing in the lower regions of the pot risk being deprived of too much oxygen in the soil if conditions stay wet with frequent watering (and the slower evaporation that can occur indoors).

Miri

You're welcome.

We do not accept plant samples and we help to diagnose homeowner plant/insect problems via this website. Master Gardeners conduct plant clinics at Farmers Market Locations in your county but do not start until May.   You may be able to bring your plant to a location at that time. Here is a link for more information. 

As mentioned in our previous responses and based on your photos, you may be dealing with several issues. Nutrition, old soils (as mentioned in your previous emails), possible old insect damage (monitor for new damage), and  moisture (too much or too little), not enough light, etc. 

The plant is not actively growing now and it will not improve much.  It is difficult to keep going. We see signs of new growth and that is a good sign. You can monitor for any possible insects.  Put out yellow sticky traps around the soil line of the plant. Water when the top make sure the top inch or two is getting fairly dry before giving the pot another thorough watering.  Make sure the container has holes for good drainage and if it has a saucer underneath empty excess water. Clean the container and Repot in late February/early March with fresh potting soil.You can fertilize with a balanced houseplant fertilizer during the growing season only following directions on product label.  Take outdoors after all danger of frost is past. There is not a lot of information growing avocado as a houseplant. Here is a link for more information. 

Also, starting an avocado from the seed/pit is a fun and easy way to grow a free houseplant but life expectancy is not long.  If you want fruit, you would have to start with a grafted tree. Grafted avocados produce fruit in 2-3 years. They are tropical plants and not cold hardy. 

Marian

You are welcome.

Marian