Grafted versus Non-Grafted Passionfruits – Possibility for alternative rootstock options?

Now, there are very few people from experience that don’t like eating Passionfruits in some form or another. Common, easy to grow and sweet, these relatively thirsty climbers have been grown by households in Australia for a long time.

When you go to acquire an edible Passionfruit plant in Australia you have a few main options; the variety – Black, Panama, Banana, and whether it is grafted or un-grafted. First available in the season are the grafted var’s as the non-grafted take a little longer to get going. You may be wondering… whats the real difference?

Happily growing and fruiting amongst native vegetation by creek no rootstock required
Naturalised Black Passionfruit

I personally avoid buying grafted Passionfruits as the rootstock used is from an exceptionally weedy Passionfruit variety from South America called Passiflora caerulea. The reasons given for its use as a rootstock is that it is cold-hardy and disease resistant, but it also readily sends sub-surface runners and shoots out which have to be constantly kept back or it will quickly overtake the top of the graft (desirable bit) and probably a lot more of your yard! Vigorous to the point that it will smother vegetation in yard and bush alike, it also produces natural cyanide in its stems, leaves and immature fruits so don’t let livestock or other animals (incl. children) eat it either.

I feel that part of the reason Blue Passionfruit is so frequently used as rootstock may be that a single plant will produce 1000 plants for grafting onto due to its running habit and that saves money, effort and time growing 1000 whole other rootstock plants as grafting fodder.

If you live in an area like Victoria or inland that has much colder periods of the year, the

Passiflora herbertiana fruit
Passiflora herbertiana fruit

Blue grafted varieties may be right for you. The rootstock being a bit less excessively-vigorous in the cool but you’ll still need to keep an eye on those runners as it can still be a weed in these areas. Possibly growing these in a container may help you to restrict much of this unwanted spread.

If you live in an area classed as warm-temperate, subtropical through to the tropics you’ll be able to grow non-grafted Passionfruit quite easily and with much less maintenance. The trouble more seems to be keeping water up to them in a low input system. Ie; minimal fertilisation, watering etc. tending to do much better in a partially sheltered understorey situation.

Three colour shades over flower age.
Passiflora herbertiana flowers

The main basis for this post is that i’m growing a native Passionfruit (Passiflora herbertiana) which is a bushfood local to the NSW east coast and ranges, into Queensland. The fruit itself is small, edible and sweet but has a distinct aftertaste. I havn’t heard of anybody trying this but I wonder if using this native species as a rootstock could reduce the relatively high water requirements of the cultivated Passionfruit varieties. At least for the areas where the native has natural distribution. I believe Passiflora herbertiana is not as cold hardy as Blue Passionfruit but having evolved in an arid country like Australia I assume it is more ably adapted to drought and minimal irrigation. Also the risk of it taking over or becoming an environmental weed is about zero.

Currently just an idea, if you’re reading this and have any input or thoughts I’d greatly appreciate the discussion. 🙂

4 thoughts on “Grafted versus Non-Grafted Passionfruits – Possibility for alternative rootstock options?

  1. Thanks for the background on the grafted vs non-grafted versions. I’m intending to grow passionfruit along the pergola on the side of my house and I hadn’t heard about the natural cyanide feature of the Passiflora caerulea. I don’t want anything potentially poisonous around when I have a 2 year old.

  2. At last it is a reassurance to come across someone else who is concerned with the environmental risks posed by the root stock of the Nellie Kelly passionfruit. I live in Tasmania and am, after 5 years still trying to eradicate the invasive root stock vine that I constantly discover sending new shoots through my garden. In places it has reached to the top of a gum tree before I discovered it, and has rapidly grown to a thickness of one inch in diameter. It has , as yet not escaped into the nearby bushland as I have found and removed it before it could flower. This is not the case where I see it having taken over large tracts of bushland in gullies , creek beds etc around Hobart where it appears to be no one’s responsibility to address the problem. It should be classified as a noxious weed and plant nurseries prohibited from selling it. Nellie Kelly produce a non-grafted stock and , as the author rightly says, an alternative root stock should be found that is benign.

    1. If you did, you would have to redevelop roots from the scion (top half) to replace it and it is unlikely to happen before the vine dies off. It would be much more feasible to just buy a new ungrafted or alternatively grafted Passionfruit.

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