Growing avocado tree from seedling is a hit-or-miss endeavor

Avocados, avocados, avocados!

We have had an abundance of avocados this year at my sister-in-law’s house. We have estimated that more than 400 pounds have been picked and there are some too high to reach that are falling to the ground.

The tree is a seedling that was given to her and my brother-in-law more than 40 years ago by a good friend. When they received the avocado in a plastic container, it was two feet tall and the top half of the avocado stone was showing through the soil. The plant was sprouting from the split in the middle of the stone.

My brother-in-law planted the small tree in their backyard, 10 feet away from the house and four feet away from the side yard fence. After all these years, that beautiful tree is now at least 55 feet tall, more than 20 inches in diameter and covers the roof, their neighbor’s roof and all of the side yard.

This tree has a large yield one year, followed by a small yield the following year. This year was the largest crop it has ever produced and we were eating avocados daily. It took 15 years for this particular tree to produce fruit, but it provided shade over the patio and protected the west side of the house. The fruit is dark green on the tree, camouflaging itself among the leaves. When ready to harvest they turn black.

Once the tree began bearing fruit, it hasn’t stopped. This year the fruit grew like grapes (in clusters) and were as large as your closed fist. It will be interesting to see what the tree produces this coming year.

The avocados produced are thin-skinned and creamy. You can scoop the meat out and spread it like butter on bread. We were looking for innovative ways to eat them. We even had delicious key lime pie made with avocados. Our son drove to Solano County from Fair Oaks on three separate trips to pick avocados this year. He spent an average of three hours each trip filling grocery bags and boxes. My sister-in-law’s garage was wall to wall containers filled with avocados and we were giving them away to everyone: family, friends, neighbors, the mailman (you get the picture).

Why this tree has survived is beyond me. It has not received any special care, is planted too close to the house and the ground around it has been covered with a cement patio. Occasionally, my brother-in-law would spread some granular avocado food around the trunk for fertilization. Seedlings do not always produce regular-sized fruit. I have seen some that bear dwarf finger-sized avocados that are mostly the pit or some that produce no fruit at all.

How to start your own seedling avocado tree

• Purchase an avocado. Carefully remove the pit from the avocado (without cutting it) then wash clean of all the avocado fruit. You may need to soak the pit then lightly scrub it. Be careful not to remove the brown skin on the pit, as it is the seed cover.
• Some avocado pits are oblong, whereas others are shaped like perfect spheres. All have a bottom from where the roots will grow and a top from which the sprout will emerge. The slightly pointier end is the top and the flat end is the bottom. In order to get your pit to sprout, you will need to place the bottom root end in water.
• Pierce the seed with four toothpicks and stick them firmly and at a slight downward angle. Space them evenly around the circumference of the avocado. These toothpicks are your avocado scaffolding, allowing you to rest the bottom half of the seed in a jar.
• Place seed half submerged in a glass of water. A pint canning jar works well. Set on a bright windowsill. Change the water regularly (every five days) to prevent mold, bacteria and fungus growth, which will doom your little avocado sprout.
• Be patient. It takes at least eight weeks to get a sprout. You will see the avocado pit dry out and form a crack. The outer brown seed skin will slough off. The crack will extend to the bottom of the seed and through the crack at the bottom a tine taproot will emerge.
• The taproot will grow longer and may even branch. Eventually a small sprout will peak through the top. Do not allow your taproot to dry out ever, or you will lose your plant.
• When the sprout is seven inches tall, cut it back to about three inches to encourage new growth. When it grows another six to seven inches, plant it in an eight-inch diameter pot into a rich, humus (bagged) planting mix. Leave the top half of the seed exposed. Place on a sunny windowsill. Avocado plants love sun. Water frequently as the soil should always be moist but not soaked. Yellow leaves would indicate that you are over-watering. If this happens, let the plant dry out for several days.
• When the sprout reaches about 12 inches, pinch and remove the top two sets of leaves. This will promote side shoots and more leaves. Each time it grows another six inches, remove the two newest leaves on top. Your plant should look “bushy.”
• Avocado plants seem to attract aphids. If you get these tiny insects, spray your plant with water and a small amount of dishwashing detergent. Add a teaspoon of Neem oil. This should solve your problem, but if not, repeat above process a second time.
• Will my seedling avocado ever have fruit? Some will after three or  four years, others take 15-plus years to produce fruit and then again some never do. Sometimes it helps to have several trees growing together to aid with pollination. Don’t expect your seedling to have fruit anything like the avocado that yielded your seed. Commercial avocados are grown from grafted branches that control the outcome of the fruit, but a naturally grown avocado may be quite different from its parent.

Sharon Rico is a Master Gardener with the University of California Cooperative Extension office in Fairfield. If you have gardening questions, call the Master Gardener’s office at 784-1322.