The great indoors
Their fleshy fruit has become the breakfast choice of millennials, but avocados also make excellent houseplants that can easily be propagated at home
Jess Snowball looks at avocados, excellent houseplants that can easily be propagated at home
The avocado plant was first described by Linnaeus, in his Species plantarum of 1753, as Laurus persea, but a year later the English botanist Philip Miller realised the plant collected from the West Indies required its own genus and renamed it Persea americana. Today, avocados are grown for their highly nutritious, fleshy fruits in many parts of the world, including the West Indes, Mexico and Guatemala. There are several different cultivars, all of which are tender, evergreen trees. Most grow to around 20m and thrive in warm, sub-tropical areas, although there are some dwarf cultivars and some hardier Mexican avocados that can be cultivated in cooler areas. Surprisingly, although their pear-shaped fruits have a single seed (the pit or stone) at their centre, they are classed as berries rather than drupes.
Avocados make excellent houseplants, offering a flush of large, glossy, mostly oval leaves that can grow up to 30cm long and which form a striking umbrella arrangement. They thrive at room temperatures, but grown as houseplants they tend to be short-lived; they don’t like to be kept in a container for too long and after two to three years of container cultivation their foliage will begin to deteriorate, so it is a good idea to replace them on a regular basis. Once established they can, however, be planted outdoors in frost free areas and grow successfully in sheltered gardens.
My own Persea is two years old, and is growing slowly and happily on a large, north-facing windowsill. Unfussy about light and sporadic waterings, it towers above a lower canopy of
propagules, succulents and moss domes.
Cultivation
Avocado plants are not that easy to come by in the UK, but they are easily raised from seed, which comes true to type, and can be propagated from any shop-bought fruit using grafting, layering or seed propagation. There are several starter grower kits and hydroponic planters available (see suppliers below) but you can very easily create your own by using three wooden toothpicks and a glass. Wash the seed with water, then push the toothpicks at a slightly downward angle into the widest part of the seed so they are equally spaced around the circumference. Balance the toothpicks on the edge of a half-filled glass of water so that the seed is suspended in the centre of the glass with its base (the flatter, dimpled end) submerged in around two to three centimetres of water. Place the glass in a warm, sunny spot and keep the water topped up, and in around four to eight weeks you should see roots start to emerge from the base. Later, after a period of roughly eight weeks, the plumule (or first shoot) will appear from the top, or pointy end, of the seed. Avocados can grow in water for quite some time, but once you can see that sufficient roots have developed, transfer the propagated avocado into a potting mix of John Innes No.3 with added sand and grit. You can also propagate Persea in compost. Soak the seed in hot water (40-52°C) for 30 minutes and then trim off the pointed tip of the seed using a clean, sharp knife. Place the soaked seed in a pot of moist seed compost so that the cut top of the seed lies just above the compost’s surface. It should germinate in about four weeks.
When you find that the soil of your plant is starting to dry out more quickly than usual, or that roots are beginning to poke out of the bottom of the pot, then this is a sign that it is time to repot your plant. This is best done on an annual basis in spring.
Although your seedling has the potential to grow into a small tree, it is unlikely to bear fruit as fruiting specimens typically need to be at least ten years old and tend to be grafted on to a compatible rootstock to do so.
SUPPLIERS OF STARTER GROWER KITS Dowse dowsdesign.co.uk
Trouva trouva.com
Jess Snowball is glasshouse manager at the Chelsea Physic Garden, London.