11 May How (and Why) to Grow Avocados
By Dr. Mercola
Avocados are one of the healthiest foods you can eat every day. They’re rich in monounsaturated fat that your body can easily burn for energy, and the fat helps your body absorb fat-soluble nutrients from other foods as well. Research1 has shown consuming a whole fresh avocado with either tomato sauce or raw carrots significantly enhanced absorption of the carotenoids and facilitated the conversion of them into an active form of vitamin A.
Another study2 found that adding avocado to salad allowed the volunteers to absorb three to five times more carotenoid antioxidants, which help protect your body against free radical damage. Avocados are sometimes pricy, but you can pick them up when on sale; just make sure they’re hard, and then store them in your refrigerator. They’ll stay fresh for about two to three weeks this way. Placed on the counter, they’ll ripen in a day or two.
An even better way would be to grow your own. Here, you have two options: 1) Purchase a grafted avocado tree from your local nursery, or 2) Grow it from seed.3,4,5 If you start from seed, keep in mind your plant may or may not actually produce fruit. Some may start producing fruit after three to four years.
Others can take up to 15 years, and some never fruit at all. Commercial avocado orchards use grafts, which is the surest way to get fruit. Growing it from seed can be a fun experiment, however, and is a great project for kids. Here’s how.
8-Step Guide to Growing Avocados From Seed
Step 1: Start by removing the pit from a fresh avocado. Be sure not to cut or score the pit during removal. Wash off any remnants of the fruit, but make sure you don’t remove the brown seed cover.
Step 2: Next, determine the top and bottom ends of the seed. More often than not, the seed will be slightly egg-shaped, and the bottom would be the thicker, flatter end. The bottom end is where the roots will form.
Step 3: With the top end up, pierce the seed with four toothpicks, about three-quarters of the way down, angling slightly downward. Place into a glass or small bowl of water, so that the water covers the bottom end of the seed while keeping the top end dry and above water.
Step 4: Place the glass on a windowsill that gets plenty of sunlight. Change the water at least once a week or more to prevent fungal growth.
Step 5: Patiently wait for the seed to sprout, which can take anywhere from two to eight weeks. As the roots begin to sprout, make sure the taproot (the longest of the roots) never dries out. The roots need to remain submerged or the plant will die.
Step 6: Once the stem has formed and grown to a height of about 6 inches, cut it down to about 3 inches to encourage new growth.
Step 7: Once the seedling has reached a height of 6 or 7 inches again, and roots are at least 2 to 3 inches long, transplant the seedling into a pot (6 to 10 inches in diameter) of humus-rich soil, leaving the top half of the seed above the soil line. Keep the pot on a sunny windowsill.
Step 8: To encourage bushiness, pinch two of the longest sets of tops once the plant is about 1 foot tall. Continue pinching the two youngest sets of branches for every 6 inches of growth.
In the summer, you can place your baby avocado tree outdoors in a sunny spot. The more sun the better; just make sure the soil doesn’t dry out completely. If temperatures drop below 45 degrees F., you’ll need to bring the plant indoors, so avoid planting it in your garden while it’s still young, unless the temperature never drops below 45 F.
Basic Planting Guidelines
Avocado trees grow well in USDA zones 9b through 11. As noted in the featured video by California Gardening, your best bet, if you want to produce fruit, is to buy a grafted tree. Since avocado trees are shallow rooted, their feeder roots being only about 6 inches below ground, make sure your soil is well aerated. Plant in spring once there’s no longer any risk of frost and the soil has warmed.
Avoid planting your tree near lawn or other plantings that might compete for nitrogen uptake. Ideally, your soil should have a pH of 7 or below. If your soil is more alkaline, amend with organic matter before planting. Sphagnum moss is an ideal amendment. To lower soil pH by 1 unit, add 2.5 pounds of peat moss per square yard of soil.6 Alkaline soils will also need some chelated iron. You can tell your tree is deficient in iron if new leaves have green veins and start to yellow around the edges.
Select a sunny spot, and as with other plantings, dig a hole as deep as the root ball and about 50 percent wider. Fill in with soil and add mulch to lessen water evaporation and weed growth. Using a weed barrier around the base will further minimize weed growth. Keep the mulch at least 6 inches away from the trunk of your tree.
Newly planted trees will need about 2 gallons of water at the time of planting. After that, water two to three times a week until established. The tree will flower in March or April, producing tiny fruit buds shortly thereafter. In the first year, apply fertilizer in March, June and September. Compost and fish emulsion are good organic options. You may also add a little zinc once a year.
Throughout the growing season, prune off any dead leaves and remove weeds growing near the trunk. Insecticides are typically not required. Should you notice insects, snails or slugs, sprinkle diatomaceous earth on the soil around the tree. It’s a natural repellant against many crawling insects.
Popular Avocado Varieties
When selecting a tree, you have a number of options. Some varieties are more cold-hardy than others, so make sure you select a variety that is suitable for your climate. Popular varieties include:
The featured video focuses on the Gem variety, a dwarf variant of the Gwen that produces large, fleshy fruit with an excellent buttery flavor. The fruit also oxidizes slower than the Hass variety. It’s a heavy producer, making it a good choice for backyard growing, and it produces fruit annually. It grows best in South California and areas with similar climate. The Haas and Reed varieties are “alternate bearing,” meaning they alternate between heavy production one year and low production the next.
How to Harvest and Peel Avocados
Avocados do not ripen on the tree. They will only ripen after they’re picked. Refrigerated, they will ripen very slowly, whereas left on the counter, they’ll ripen and soften in a day or two. In warmer climates, you can leave the fruit on the tree well into December. Simply harvest what you need as you go along, picking the fruit a couple of days before you plan to eat it.
Interestingly, how you de-skin your fruit can have a bearing on the nutrients you get from it. In 2010, the California Avocado Commission issued guidelines7 for getting the most out of your avocado by peeling it the right way:
“California-grown avocados contain 11 carotenoids … that may provide numerous health benefits. Carotenoids appear to protect humans against certain cancers, heart disease and age-related macular degeneration. The UCLA research showed that in California avocados, the greatest concentration of beneficial carotenoids is in the dark green fruit of the avocado closest to the peel.”
To preserve the area with the greatest concentration of antioxidants, you want to peel the avocado with your hands, as you would a banana:
- First, cut the avocado lengthwise, around the seed
- Holding each half, twist them in the opposite directions to separate them from the seed
- Remove the seed
- Cut each half, lengthwise
- Next, using your thumb and index finger, simply peel the skin off each piece
Five Reasons to Eat Avocados
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There are many reasons to eat avocado on a regular basis, and so many ways to eat them. They can be added to salads and smoothies, for example, or used as fat replacement in baked goods and desserts such as chocolate pudding, made with avocado and raw cacao. For a healthy chocolate avocado pudding recipe, see this page. As mentioned above, avocados contain many valuable antioxidants known to have powerful anti-cancer activity. They also contain:
1. Potassium. About 2.5 avocados provide the daily recommended amount of about 4,700 milligrams (mg) of potassium a day. Potassium is a mineral and an electrolyte that conducts electricity in your body that plays an important role in heart function, skeletal health, digestion and muscular function, and is essential for the proper function of all cells, tissues and organs.
Importantly, consuming enough potassium-rich foods helps offset the hypertensive effects of sodium. Imbalance in your sodium-potassium ratio not only can lead to hypertension (high blood pressure) but may also contribute to heart disease and stroke.
2. Magnesium. An average avocado contains about 40 mg of magnesium, which is about 10 percent of the recommended daily value. Magnesium is a mineral used by every organ in your body, especially your heart, muscles and kidneys. If you suffer from unexplained fatigue or weakness, abnormal heart rhythms, or even muscle spasms and eye twitches, low levels of magnesium could be to blame.
3. Vitamins C and E. Vitamins C and E are important antioxidants on their own, but put them together, the way they are in avocado, and the real magic happens. As reported in Critical Reviews in Food, Science and Nutrition,8 “Avocados are one of the few foods that contain significant levels of both vitamins C and E.
Vitamin C plays an important role in recycling vitamin E to maintain circulatory antioxidant protection …” Research9 has also shown a combination of vitamin C and E can help slow plaque buildup, which could help prevent a heart attack or stroke.
4. Fiber. Avocados are surprisingly high in fiber, with about 4.6 grams in half an avocado. Fiber plays an important role in your digestive, heart and skin health, and may improve blood sugar control, weight management and more. In fact, their fiber content appears to be one of the reasons why avocados are so good for weight management and blood sugar support.
According to research10 published in Nutrition Journal, eating just one-half of a fresh avocado with lunch may satiate you if you’re overweight, which will help prevent unnecessary snacking later. Those who ate half an avocado with their standard lunch reported being 40 percent less hungry three hours after their meal and 28 percent less hungry at the five-hour mark compared to those who did not eat avocado for lunch. The study also found that avocados appear helpful for regulating blood sugar levels.
5. Low risk of chemical contamination. Avocados are rated as one of the safest commercial crops in terms of pesticide application, and this is largely because their thick skins protect the inner fruit from pesticides. Hence, there’s no real need to spend extra money on organic avocados.
How to Keep Your Avocados Fresh
The flesh of an avocado turns brown once it’s cut because of an enzyme that oxidizes when exposed to air. There are a number of tricks to keep avocados fresh. Here are a few helpful pointers:
- If you’ll be using only half an avocado at a time, leave the pit in the half of the avocado you’re not planning to use and store it in an airtight container in the refrigerator.
- If you’ve scooped the avocado for guacamole, store the pit in the leftovers.
- Prevent oxidation by adding a thin layer of olive oil onto the top of the avocado half using a pastry brush. You can use this trick with guacamole too. It will, however, add an oilier flavor and texture to your dip.
- Lemon juice also inhibits oxidation. Rub some on an avocado half or sprinkle some on top of your guacamole. It will add some lemon flavor to the avocado, which may or may not be desirable depending on your intended use.
- Place a handful of large onion chunks into the bottom of the container and then place the leftover avocado half (face up) on top. Alternatively, sprinkle some cut onion on top of your guacamole, and remove them when it’s time to serve.
Source: Dr. Mercola Blog