Indoor avocado plant stopped growing

(Question)

In September I pinched off the top of new growth hoping it would bush out and develop another bud or buds. Since that time it has stopped growing. The avocado plant pit dried out and fell off. In October I replanted it in a terra cotta pot with indoor light potting soil from garden centre rather than cactus miracle grow from Canadian Tire. I bought led full spectrum lights. As you can see they are not the ultra violet lights. I water the plant when the moisture guage says 2. (It goes 1 as dry through 4 as wet). The plant is placed in an East window and did well April through August with windows open and sun between 8am through 1pm. Not always direct sun. Ever since the tip was pinched off no new growth. The top leaves are nice and green. The bottom leaves have tiny brown tips due to I am assuming chlorine from tap water. I normally let my water sit a week. When I repotted the avocado plant from the previous plastic pot it was pot bound. The roots after washed off looked a creamy colour not dark brown. I cut back some of the roots, just the tips of some, but still abundant with roots. Currently air flow is restricted because of winter. Wondering if the plant went dormant until it gets warm enough to open my windows again. The trunk looks healthy. I had a bad case of gnats in September, but got rid of them from sticky paper and gnat killer seeds which I didn’t use. Do I need to repot in a bigger pot? The current terra cotta pot is 7.5 inches across. Can you help?

(Answer)

Thank you for writing: whether you grew your plant from seed, or inherited it, nurturing an avocado plant indoors can be a rewarding horticultural experiment. A brief bit of background: the avocado belongs to the plant family Lauraceae, or Laurel, which also includes cinnamon and bay laurel. Avocado are grown throughout the world where there is sufficient warmth, sunshine, water, desired soil and situation for excellent drainage.

For indoor growing of a fledgling plant, one needs to replicate these cultural requirements, as best as possible.

  1. It seems you have both “pinched off the top of new growth”, and also “cut back some of the roots, just the tips…”, when you re-potted the plant. You don’t mention why you pruned the roots. This is a lot for your plant to be dealing with right now, and it is possible the system is currently working on re-establishing the root system, before it can put energy in to new leaf growth;
  2. The process of “washing” the roots could very likely have damaged the very important root hairs of the plant’s system;
  3. Your question is, “Do I need to repot in a bigger pot”: you moved the plant from a plastic, to a terracotta pot. Unglazed clay pots are porous, and will promote loss of soil humidity: not pleasant for your avocado. You may want to re-locate your plant back to a new, clean, same-size (7.5″) plastic pot, as carefully and gently as possible, so as not to disturb any new regenerative root growth. Ensure the pot has open bottom drainage holes, stay with the existing soil for now (treat the roots ‘with kid gloves’), and put the pot in to a large saucer that, going forward, can catch all run-off water, after regular, quenching watering.

We’re providing a link for yourself, and other like-minded readers, to review how well you have done well thus far in raising an avocado.

While you nurture your plant back to good health, please know you’re not alone with avocado-growing challenges. For further research, also see our Toronto Master Gardener reply to a prior question with concerns — not dissimilar to yours — re ongoing culture of an avocado plant and common problems.