Maypop or May Not – pushing the zone with Passiflora incarnata

Old Faithful, the tropical passionflower (species unknown) that has been going from greenhouse to windowbox and back again for years has brought us a great deal of pleasure. The thing’s an unkillable blooming fool that makes about 14 feet of growth each summer.

But it’s also brought us a great deal of aggravation. Moving large plants back and forth between the Maine coast and the Hudson Valley is not my favorite thing.  

So wouldn’t it be great to have a passionflower that was willing to live outdoors? YES! Passionflowers are almost all denizens of zones 9 and south, but there is one, the native Passiflora incarnata, rated hardy to Zone 6 or 7 – and we are almost 6.

P. incarnata’s common name, Maypop, supposedly comes from the way it springs up suddenly very late in spring – a clue that it’s happiest in warmer climates (nothing late about May around here).

The two healthy vines that came last April were therefore given choice cosy spots: right next to the house facing East, with plenty of light from the South.

No matter. They sat and sulked for months, remaining the same 18 inches tall well into July. Then whammo!  In the space of about 2 weeks they were halfway up their trellises, sporting multiple shoots and even a few buds. And that’s when I learned about the ants. Big black stinging ants love maypops; they were all over the vines and very aggressive about defending their territory.

 There HAD been a lot of insect warnings, just not about the ants. Maypops are frequently chewed to shreds by the caterpillars of the Gulf Fritillary, Agraulis vanillae.

utterly gorgeous underneath.

Making the caterpillar damage definitely something worth putting up with – except that there was never a sign of anything lepidopterous.

Might be we’re too far north, the Gulf Fritillary page where I found Dr. Bryant’s photos describes it as a tropical species and the map at Butterfliesandmoths.org, which does show it venturing quite a bit northward, does not record any sightings in New York.

IF (big if) the vine comes back for a few years the butterfly situation may improve, but I’m afraid there’s also a chance that the deck is stacked against. Even if the ants don’t get ’em, the caterpillars are probably no match for our September surprise.

She stayed around for several weeks, laying eggs I hope.

Warning Note for Southern Readers: P. incarnata may be native, but that doesn’t mean it’s completely benign. Where not kept in check by mown lawn, asphalt (or, possibly, infestations of A. vanillae) maypop can run near-amok… and be nearly impossible to eradicate.