Why won't my avocado seed sprout?
Written by
Paul Reynolds
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.When trying to *grow avocado seed*, you may have already experienced failure due to a combination of three suspects: immature pits, incorrect temperature, or fungus. I've salvaged many seeds from failure after the issues were ironed out. If you float your seed to start out with, viable seeds will sink and have an unblemished brown coat on the surface. Immediately discard seeds that are oriented sideways in the water as they are no good.
Seed Viability Checks
- Submerge in water: viable seeds sink
- Inspect for cracks or mold spots
- Select plump, oval-shaped pits
Temperature Control
- Maintain 70-75°F (21-24°C)
- Use seedling heat mats in cold rooms
- Avoid drafty windowsills
Mold Prevention
- Swap paper towels every 5 days
- Add cinnamon powder as natural fungicide
- Ensure proper ventilation
Increase germination success by prepping seeds properly. I soak the seeds in 110°F (43°C) water in a container for 30 minutes, which softens the coats of the seeds. I also use a clean knife to score vertical lines on the surface of the seed, which allows for faster water absorption. This technique has reduced my germination time from 8 weeks to 5 weeks.
Moldy Seeds
- Scrub gently with soft toothbrush
- Soak in chamomile tea for 2 hours
- Restart in fresh paper towels
Dormant Seeds
- Apply gibberellic acid soak
- Switch to sphagnum moss medium
- Increase light to 14 hours daily
Keep careful track of things over time. I take pictures of seeds every week next to a ruler to show any color changes. Healthy sprouting seeds will have creamy roots and some green growth at the top by about the 4-week point. If you have any seeds that are black or smell off, throw them out. They can't recover. If necessary, start with new pits.
Read the full article: How to Grow Avocado Seed Successfully Every Time
