How to grow pineapples
Kate Marshall shares all you need to know about planting, growing and harvesting pineapples at home.
Harvest homegrown pina coladas!
Pineapples are surprisingly small plants, as they are low-growing bromeliads with a spread of less than a metre in height and width.
In New Zealand, growing pineapple outdoors is limited to the winterless north and other warm, frost-free spots. But planting in a glasshouse or growing as a houseplant (for winter at least) is the next best thing.
It can take several years for a plant to reach cropping stage, and when it does, each rosette will produce one pineapple on a stalk.
The best spot
Pineapple plants can be grown outdoors in a warm and sheltered position. They can withstand a very light frost, but cannot tolerate longer periods of low temperatures as their roots can’t handle cold, soggy soil.
The plant will be quicker to fruit with more warmth.
Pineapples can also be grown in a pot on a sunny deck to keep roots warmer; just bring them in under cover in winter. Pineapples make great houseplants, especially the red variegated type, but would need to be in a spot in full sun to produce fruit.
In a glasshouse or tunnelhouse, either plant directly into the ground or in a large pot.
Each plant only produces one fruit at a time, so you might want to plant several if you’re a big fan.
Growing tips Unlike most bromeliads
which like a free-draining, light soil, pineapples need rich ground to get decent-sized, good-flavoured fruit.
Fortunately, because subtropical plants are relatively uncommon here, there are very few of the associated pests and diseases as there are simply not a lot of host plants for them to thrive on. Pineapples are therefore not susceptible to any pests or diseases in New Zealand, so can be grown organically.
Varieties Unsurprisingly, homegrown
or New Zealand-grown commercial pineapples are superior to the imported fruit, simply from being harvested when fully ripe. The flavours are strong and the flesh is very juicy – just like eating marketbought pineapples in the tropics.
Choose a variety with smooth leaves ( Ananas comosus) to make the plant more pleasant to be near in a confined space.
Commercial varieties are ‘Queen’ and ‘Cayenne’, from the species
Ananas comosus which is indigenous to South America. The plants are reasonably frost tender so should only be planted in a very warm site or under cover, ideally with a brick or concrete block wall behind to reflect light and heat.
Ananas bracteatus is known as the mountain pineapple or red pineapple, and originates from South America (particularly Brazil, where it grows at 140-320m above sea level). While this species is considered more of an ornamental plant with its decorative red fruit and pretty flower, the fruit is in fact deliciously edible once fully ripe. The leaves are long straps with sharp spines, so should be planted with plenty of space – or as a security hedge!
The variegated form of the red pineapple ( Ananas braceatus var.
tricolor) is even more spectacular than its mother, with yellow and pink stripes on the prickly strappy leaves. The plant makes an excellent houseplant with an indigo-purple flower. The resulting fruit is edible once the pink tones have turned yellow, and a sweet fragrance is released. If not fully ripe, the flesh has enamel-stripping acid levels.
Pseudananas sagenarius is also known as Ananas sagenaria or the false pineapple. Very closely related to the true pineapple, it is thought to possibly be a cross between Ananas comosus and another bromeliad.
Pseudananas sagenarius is said to be hardier than other types, but the fruit is not quite as sweet and flavoursome. Despite being described as a hardy pineapple, it still needs a very warm spot to thrive.
Pseudananas sagenarius also has brutally spiky leaf straps so should not be planted in a narrow space.
Harvesting Like bananas, pineapple plants
seem to need a certain number of leaves to set fruit.
Even in the warmest New Zealand climates, they are slower growing than those in parts of the tropics where pineapples are commercially grown (such as Vietnam, Thailand, Hawaii and North Queensland).
Here, the plants can take around two years from planting to flower, though in a hothouse, it could take as little as 14 months.
From flowering time, the fruit will
Homegrown pineapples are superior to the imported fruit, simply because they are harvested when fully ripe.
be ready after about six months. It will be unmistakably sweetly fragrant to indicate its readiness for eating.
Don’t give in to the temptation to pick the fruit early, as it doesn’t ripen once picked (and will be very acidic and unpleasant).
To harvest, simply cut the ripe fruit from the stalk using a sharp kitchen knife. Ripe fruit should be eaten within a few days as it bruises and rots quickly.
Sourcing plants Up until relatively recently,
imported pineapples had a bushy head which could be used for propagation. Unfortunately, due to biosecurity restrictions, these spikes are now removed so the supermarket fruit cannot be used as a source of plant material.
Each pineapple rosette will produce a few pups around the base which can be trimmed off and rooted. So if you are lucky enough to know someone with pineapple plants, just ask for a few pups to start your own pineapple plantation.
The pups should be grown in a warm spot, ideally with bottom heat. Some varieties, like the red variegated type, produce up to 20 pups each year. The pups can be left on to make a bushier plant with more fruit or separated off to make more plants for your own garden or to share with friends.
The head of the pineapple itself can also be used to grow a new plant.
Garden centres sometimes stock pineapple plants. Buy online at Nestlebrae Exotics (nestlebrae.co.nz) or try visiting your local bromeliad club or Trade Me.
Plant before the end of February, tender tropicals don’t like to start life in cooler months. Plant subtropicals when the weather is subtropical!