How To Prepare Soil for an Avocado Tree 


As gardeners, we know the soil is one of the most important aspects of any plant’s growth. If you’ve decided that growing an avocado tree is in your future, you may be overwhelmed with all the information out there. I will break down the preparation process for soil, specifically for growing your best avocado tree. 

Here’s how to prepare the soil for an avocado tree in five easy steps:

  1. Pick your soil.
  2. Sterilize your soil. 
  3. Add fertilizer and mulch. 
  4. Find the right pot or plot for your soil. 
  5. Water the soil.

Below, I will expand on each of these steps in-depth to help you thoroughly prepare for your avocado seed to be planted. Though there are many methods to plant an avocado tree, these soil tips will be applicable regardless of which method you choose.

1. Pick Your Soil

For avocado seeds, there are some good rules of thumb to follow soil-wise. You want soil with the following characteristics:

  • good drainage
  • low amounts of phosphorus
  • no detrimental or high volumes of peat moss

Whether you are using your native soil or are picking out a new medium for this seed, you’ll want to make sure it hits all the checkmarks above.

Good Drainage in Soil Optimizes Water Retention

Drainage in your soil simply means your soil’s ability to either hold onto water and absorb its nutrients and support your plants’ root systems. Poor drainage in soil can lead to standing water, mold, or your plants not getting the water they need at the bottom of their roots.

Determining your soil drainage is pretty simple. Giving your soil a good squeeze can tell you a lot about its moisture content. Soil that feels too sandy or slippery needs some help with drainage. Another bad sign is water pooling at the top of your soil whenever you water. 

To test for drainage ability, you can use a shovel (or spoon, depending on the size of your pot) and your waterer of choice to observe how long it takes for your water to drain through a hole. If you dig a one foot (0.30 m) wide by one foot deep hole, it shouldn’t take any more than ten to thirty minutes for the water to fully drain, according to gardening experts at HGTV. 

Use a Pot With Holes for Optimal Soil Drainage

To fix drainage issues in a house plant, make sure your pot has holes at the bottom to drain water. If you have a plant pot with no holes, you can add lava rocks or wood chips at the bottom of your plant to encourage drainage and keep standing water or mold at bay. 

For a larger area, like your yard or a big garden bed, make sure you add plenty of organic matter to the growing environment. This means mulching, composting, and ensuring your soil is a rich place for microorganisms to live. Fertilizers and manure may also help improve soil drainage if you’re planting your avocado seed (or growing tree) into your yard. 

Checking for pH and Phosphorus Content

Phosphorus, zinc, nitrogen, and potassium are essential nutrients for your avocado tree. Soil should be nutrient-rich, have lots of tiny microorganisms cultivating it, and should also have lots of organic matter within it. 

If your soil is dry, lacks microorganisms, or worse, has infestations and pests in it, your avocado tree won’t thrive. Additionally, if you have too much of a certain nutrient, your tree may suffer. 

If you’d like to be sure of your soil’s richness, you can send it in for a test or test its pH on your own. This video highlights a simple at-home testing kit that can give you some insight into what you’re working with:

Suppose you don’t want to add pH testing to your to-do list. In this case, no worries. Again, you can ensure your soil is rich in nutrients by providing lots of organic matter to nurture it. New potting mix is essential every once and a while for potted houseplants. 

2. Sterilize Your Soil

If you are using old soil or recycling soil from your gardening patch to grow your avocado tree, you should make sure to sterilize it. Unsterilized soil could be harboring fungi, pest infestations, or infections that won’t support your avocado tree’s growth. In fact, it could potentially harm your plant altogether.

To sterilize your potting soil, you can use any combination of the following methods:

  • Use boiling water to sterilize your soil by pouring the boiling water over your soil one batch at a time.
  • Put your soil in a microwave or an oven, ensuring the temperature doesn’t reach beyond 200 °F (93 °C)
  • Freeze batches of your soil in the freezer for a few days

Sterilizing your soil with heating or freezing methods works the same way heating or freezing your food does. It kills all harmful bacteria and viruses within the food, disrupts the life cycles of anything living within it, and prevents mold growth. 

Sterilize Soil Cautiously

Remember that sterilization will kill the good things in your soil, too. Sterilizing will bring your soil back to square one. Little to no life-supporting plant growth will be found inside of the soil after sterilization. 

You should be using new soil rich in nutrients, as we discussed above. Old, sterilized soil takes up space where healthy, rich soil can be supporting your plant. That’s where the next step comes in handy. 

3. Add Fertilizer and Mulch

Adding the right amount of fertilizer or mulch to your soil is essential in preparing it for an avocado tree. Fertilizer and mulch, in general, will provide your soil with the vitamins and nutrients we talked about in step one. It’s also important to add these substances to soil that has been fertilized.

You can get fertilizers that are explicitly rich in the things your avocado tree needs–nitrogen, phosphorus, and potassium–or find a fertilizer mix that’s rich in a wide variety of vitamins. You can also leave any fallen leaves  in the soil or near the plant to help mulch the soil. The experts at Country Living suggest adding new soil to your plant monthly or bimonthly, depending on the size of your plant and the growth of your avocado tree. 

4. Find the Right Pot or Plot for Your Soil

Even with excellent soil, your avocado tree won’t thrive without the right pot. Whether you’re setting your seed directly in the ground in hopes of an avocado-bearing tree in seven years or using the smaller version as a decorative house plant, the pot you first set it in is going to be necessary.

Wash the Pot Before Planting Your Tree

First off, you should always wash the inside of a new pot with soap and water before setting a new plant inside. We do this for a few reasons, but the most primary reason is that it protects your new plants from any harmful organisms that have been hanging out in the pot since your last planting, like pests or fungi.

Choose a Pot or Plot With Substantial Width

The right pot is going to be at least ten inches (25.4 cm) wide. Once it is too big to fit in this pot (indicated by roots outgrowing the bottom, dehydration, or the tree’s growth stopping), you can put it outside. 

Finding the right plot for your avocado tree is also an essential task. When you are ready to plant your avocado tree outside, look for a place with rich soil. You can plant your seed directly into the ground or create a protected mound for it to grow on. Just make sure this area has all the vitamins and drainage required for healthy tree growth! 

5. Water the Soil

As always, a suitable soil is going to be watered and moist, ready to welcome your avocado seed, pit, or plant into their new home. 

Some suggest keeping your plant dry for a day or two before transferring it over to a new pot. This will be relevant if you’ve already gotten your avocado tree planted in a pot but want to move it over to a plot in the ground or a bigger pot. A less moist plant makes it easier to get rid of old soil and keep roots intact. 

When you transfer your plant to new soil, moisture is essential. Once you have patted your seed or sprout into the new soil, you can rewater thoroughly to support your avocado plant’s growth. You don’t want to drench your soil before putting the new plant in, but it shouldn’t be dry and barren either. 

Final Thoughts

Planting an avocado tree, whether for decorative or edible purposes, will require properly maintained soil. In a pot or a plot, you’ll want to make sure your soil is prepped and ready to go before introducing your avocado tree. 

Prepared soil will be adequately drained, rich in nutrients, and ready to fertilize and mulch properly. Though avocado trees are fragile and unique, you’re going to use the same rules of thumb you do when planting any standard flora or fauna. Preparation is vital, but keen observation after the fact is also necessary!

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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