In a previous blog post we looked at the principle of growing your own avocados. Of course for that you need an avocado tree, but, as we explain in that post, NOT ONE GROWN FROM SEED. You can easily grow a nice avocado tree, but if it’s grown from a seed you almost certainly will never see an actual avocado – and the tree is not that pretty! If you are surprised at that, check out the post.
In this post we will get down to basics, and talk about how to grow that tree successfully – meaning so you get fruit – outdoors or in a pot.
Step 1 – Choose the Right Variety
This is step one. To have a chance of harvesting your own avocados – and that’s why you are doing this, after all – you need to start with the right variety. So where do you live? If you are in zone 10 growing an avocado tree is going to be easy, and you can grow the most popular of all varieties – the Hass avocado, Persea americana ‘Hass’. That’s the basic variety you see in stores, which has a black skin when ripe, and a green one otherwise. As you already know, it’s a great variety – versatile and tasty – and it is easy to grow in a warm enough area. Besides growing in zone 10, it will grow in a good spot in the warmest part of zone 9 (i.e.9b).
If you live in zone 8, though, or you want a plant to grow in a pot – more on that later – then go with ‘Brogden’. Never heard of it? That’s because it is more commonly known as the Cold Hardy Avocado. It’s a variety that takes more winter cold than any other. The fruit is delicious, and it has a purple skin when ripe.
Unlike many other fruit trees, you don’t need a second, different variety to get a good crop – these trees are self-pollinating. So one tree is all you need to harvest your own avocados. It is true that a second variety will increase the harvest, but these trees are incredibly prolific once established, and only commercial growers need to worry about pollination.
Step 2 – Choose the Right Place
If you are planting outdoors, choose a spot that is sunny all day long. These trees grow over 20 feet tall, and just as wide, so don’t plant within 10 feet of walls, hedges, fences or other established trees. Avocado trees grow fast, and they are happy in just about any soil that is ‘well-drained’, on other words, doesn’t sit wet for more than a couple of hours after a heavy fall or rain, and that isn’t always wet and sticky when you did a hole in it.
The Cold Hardy Avocado takes about 10 degrees of frost – that’s 22 or 23 degrees Fahrenheit. So anywhere in zone 9 is fine for it. If you live in colder zones, then you need a big tub to grow your tree in. The bigger the better, but you need to be able to move it around, as it must come indoors to a bright spot when the temperatures are too low. The tub must have drainage holes, and shouldn’t sit in a saucer of water. You could use regular houseplant soil, but soil for trees that grow outdoors would be better, if you can find it. If not, mix half potting soil with one-quarter garden soil and one-quarter of coarse sand, or perlite, or fine gravel, or fine bark chips, or a mix of these things. You need a durable, well-drained soil.
Keep your potted tree outdoors as much as possible – right down to almost freezing. Bring it inside once the thermometer gets to 35, and don’t put it out again until it reaches 40. Keep it in a bright place, sunny if possible, and a cool place, so the shock of going in and out won’t cause problems.
Step 3 – Treat it Nice
Water your new tree regularly. Let the top inch of soil dry between waterings if it is in a pot. Outdoor trees should be watered once a week for the first month or two, and then as needed if the weather is hot and dry. Once it is well-established an avocado tree is drought resistant, and survives well. Potted trees need more regular watering.
Potted trees need regular fertilizer too – use a liquid food for fruit bushes every two weeks from spring to the end of winter. Outdoor trees can be fed in spring with any fertilizer for citrus fruits (oranges, lemons, etc.)
Pruning isn’t necessary for an outdoor tree, although it can help keep it smaller and so easier to harvest. A tree in a pot will need pruning, to manage its size. Pruning an avocado is easy, and it can be done at any time of year. The simplest way is to just cut the tip off new shoots once they are as long as you think they should be. This will make them branch out, and give you a more compact tree. If the branches get very crowded, remove a few to let more sun inside. Nothing complicated is needed, but don’t let your tree get big and then hack the bejesus out of it. Little and often is the way to go.
So What Happens Now?
Once you tree has been growing for a couple of seasons, you will see the first flowers. These usually appear between March and May, depending on conditions. They are small clusters of many greenish flowers. Only about 1% will go on to form a fruit, but that’s OK, because it means each flower cluster gets one or two fruits in it. If your tree flowers indoors, take a soft artist’s brush and pass it over all the flower clusters every couple of days. Soon after, you will have fruit ready to pick – what, it grows that fast? Well no, because that will be the fruit from flowers the previous year. It takes 12 to 18 months for the fruit to grow and be ready to ripen. New little ones will be starting at the same time as the older ones are ready.
The good news is that avocados don’t ripen on the tree – they sit, like an outdoor pantry, waiting to be picked. When a fruit seems to have stopped growing, and is a good size, with a dark green skin, it’s ready to pick. Left on the tree it can be picked as needed, and they stay good that way for up to 8 months – in other words, into the fall. It’s only through winter you might need to buy some from the store – how neat is that!
Once picked the ripen, and you can tell they are ready when the skin changes color – to black in ‘Hass’, to dark purple in ‘Brogden’. You can speed things up by putting the fruit in a paper bag with a banana or a couple of apples.
So now you know all you need to know about growing avocados, and actually harvesting fruit. Enjoy the most fruity of all vegetables, and perhaps the most popular today.