Will it survive if I put it in soil? If so, how do I replant it? For example, I'd like to know what size of pot, type of soil, watering schedule, etc.?
Very much fun Kenzie! I'd like to see a picture as well, right now I imagine a 10" diameter, you do not want too big of a pot and a picture would help. Wash your new pot (clay is best) and fill 1/3 (this is approximate until I see your plant and its root system). You want the top of your avocado seed to be just under the soil and you have to have 1" from the rim to the finished top of your soil.
With your pot filled 1/3 with sterilized potting soil (please make sure there are no gimmicks such as moisture holding sponges or gels and no fertilizer added to your bagged soil) tap the pot on the floor gently to settle the soil and or gently press down.
Then you get to make a volcano in the middle and put your seed with its roots, on the top held by one hand while the other spreads the root mass out and over the sides of the volcano. Best you can. Do not worry about roots breaking and getting squished too much. No big deal but still be as gentle as possible. While still supporting the seed grab handfulls or cupfulls of soil out of the bag to bury these roots and seed. Again tamp down, shake or vibrate or tap on a surface...gently. Need to get rid of large air pockets but not to make brick.
If you are unable to get that volcano up to the perfect height to support your seed just hold it in place and spread the roots on the sides of the volcano. Longer roots, no problem. Just fold them under or over as you bury the roots and seed with more potting soil. I'd even cut them to a better length so less folding if they are humongous. That is where the picture would come in handy.
Soak this soil thoroughly, get the bottom of the pot off the surface or floor or bottom of saucer(ceramic tiles, flat rocks) a good 1/8 to 1/4 inch. Lift your pot/soil/plant soaked to learn how your pot feels when soaked. When you need to water again it will be very light. At first you'll need to keep the soil moister than normal as it transitions from water roots to soil roots. Then not so much watering.
These roots have been used to lots of water but not saturated soil. Keep this plant in the light it is used to. Wait for a month and then use Osmocote 14-14-14 extended release fertilizer. No other fertilizer or foo foo (to include coffee grounds). Be careful, do not overdo the fertilizer. You shouldn't have to add any more for 4 to 6 months. I would use distilled water, not tap water (find this on questions already answered). When roots start to show in the drainage hole it is time to upgrade to 12" pot. Until your avocado is more mature it will be needing to be upgraded in pot size little by little. Please send a picture and certainly ask questions until you truly understand what you need to do for your plant! Glad you found us!
Also, what size or what end result are you looking for? Where do you live? I hope this site works for you...I am serious, you couldn't get better advice on the internet...there are fantastic gardeners and botanists and entomologists...with answers I could have missed here and we all have different specialties as well as personalities.
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