How can I successfully grow avocados in Zone 7 or 8?

In GardeningKnowHow.com, it states avocados can grow in Zone 8. The article states:

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Cold Tolerance Of Avocado: Learn About Frost Tolerant Avocado Trees

By Amy Grant

Avocados are native to tropical America but are grown in tropical to subtropical areas of the world. If you have a yen for growing your own avocados but don’t exactly live in a tropical clime, all is not lost! There are some types of cold hardy, frost tolerant avocado trees. Read on to learn more about them.

About Cold Tolerant Avocado Trees

Avocados have been cultivated in the tropical Americas since pre-Columbian times and were first brought to Florida in 1833 and California in 1856. Generally, the avocado tree is classified as an evergreen, although some varietals lose their leaves for a brief period prior to and during blooming. As mentioned, avocados thrive in warm temps and are, thus, cultivated along the southeast and southwest coast of Florida and southern California.

If you are a lover of all things avocado and do not reside in these areas, you may wonder “is there a cold tolerant avocado?”

Avocado Cold Tolerance

The cold tolerance of avocado depends on the variety of tree. Just what is an avocado’s cold tolerance level? The West Indian varieties grow best in temperatures from 60-85 degrees F. (15-29 C.) If the trees are well established, they can survive a short-term minor dip in temps, but young trees must be protected from frost.

Guatemalan avocados can do well in cooler temperatures, 26-30 degrees F. (-3 to -1 C.). They are native to high altitudes, thus cooler regions of the tropics. These avocados are medium sized, pear-shaped green fruits that turn a blackish-green when ripe.

The maximum cold tolerance of avocado trees can be attained by planting Mexican types, which are native to the dry subtropical highlands. They flourish in a Mediterranean type climate and are able to withstand temperatures as low as 19 degrees F. (-7 C.). The fruit is smaller with thin skins that turn a glossy green to black when fully ripe.

Types of Cold Hardy Avocado Trees

Slightly cold tolerant varieties of avocado trees include:

‘Tonnage’

‘Tayor’

‘Lula’

'Kampong'

'Meya'

'Brookslate'

These types are recommended for areas that have infrequent below freezing temps between 24-28 degrees F. or -4 to -2 degrees C. You can also try any of the following, which are tolerant of temps between 25-30 degrees F. (-3 to-1 C.):

'Beta'

'Choquette'

'Loretta'

'Booth 8'

'Gainesville'

'Hall'

'Monroe'

'Reed'

The best bet for frost tolerant avocado trees, however, are the Mexican and Mexican hybrids such as:

'Brogdon'

'Ettinger'

'Gainesville'

'Mexicola'

'Winter Mexican'’

They may take a little more searching for, but they are able to withstand temperatures in the low 20’s (-6 C.)!

Whatever variety of cold tolerant avocado you plan to grow, there are a couple of tips to follow to help ensure their survival during the cold season. Cold hardy varieties are adapted to USDA plant hardiness zones 8-10, that is from coast South Carolina to Texas. Otherwise, you probably better have a greenhouse or resign yourself to purchasing the fruit from the grocer.

Plant the avocado trees 25-30 feet apart on the south side of a building or underneath overhead canopy. Use garden fabric or burlap to wrap the tree when hard freezes are expected. Protect the rootstock and the graft from cold air by mulching just above the graft.

Lastly, feed well during the year. Use a well-balanced citrus/avocado food at least four times a year, as often as once a month. Why? A well fed, healthy tree is more likely to make it during cold snaps.

- See more at: https://www.gardeningknowhow.com/edible/fruits/avocado/cold-tolerant-avocado-trees.htm#sthash.ZCSRhKla.dpufe'

https://www.gardeningknowhow.com/edible/fruits/avocado/cold-tolerant-avocado-trees.htm

south side of a building to protect from cold winds and in full sun and well drained soil. New hybrids are available but the taste is not so great.