How to Grow a Windowsill Avocado Tree

Happy National Avocado Day!

To celebrate our “alligator pear” friend, we’ve put together a brief tutorial on how to grow your own windowsill avocado tree using the leftover seed once the last bit of guacamole is gone.

Thanks to Carrie Noble, a local Master Gardener for the tips!

1. Make peace with the biome. Avocados are happiest in tropical and Mediterranean environments, so your apartment probably isn’t ideal for making an avocado toast farm. That said, small avocado plants will definitely grow with luck and love. Plus they look cool and it’s just fun to see what you can do with your food.

2. Cut and clean. Cut open your avocado, find the seed and clean it off excess green junk. It doesn’t matter if the seed is cut or scratched, big or small - almost any seed will do. Try to identify the top and bottom of your seed at this point too. The top will be pointier and the bottom will be flatter.

3. Put in water. Cut off the bottom and top ¼” to ½” with a sharp knife so that each side is flat. Push 4 toothpicks in the side of the avocado and suspend it over a small bowl of water with the bottom half to a third submerged. 

4. Wait for the roots. Put your seed-suspended-over-water on your window sill and change the water when it gets grimy. Within a few months, you should see see cracks along the seam of the seed and a tap root coming out of the bottom of your seed. If you don’t see a tap root after three months, time to make more guacamole and start again.

5. Pot the thing. Once taproot is at least 1” you are ready to pot the nascent avocado tree. Pull out the toothpicks (mostly for aesthetic and convenience reasons) and put your seed in a pot with a soil that’s a typical potting mix. Make sure the top of the seed is still visible just above the soil. Roots on avocados grow fast and deep, so make sure there’s not a lot of stuff that inhibits growth. Also, avocados don’t transplant well, so you want to start with a bigger pot than usual.

Once your seed is in soil, be patient and don’t care. If you dig your finger in and it’s dry, re-water. They’re tropical, so a little dry is OK as the plant grows up, but using more water on just after the baby seed has been potted is recommended.

Unless you see it start to mold, don’t take the pit out to check on the root. If you don’t see the top of the seed split after 2 months and something start to grow out of the tip, then your seed is no good and it’s time to start over.

Once it grows, you’ll see a couple of big leaves and a stem shoot up. It’ll seem like it grows a bit slowly, but that’s fine. The roots will do the bulk of the action.

Enjoy your new windowsill friend, and prove us wrong about the toast farm!