Puya - Growing Guide

Only once in 30 years have we managed to exhibit a huge flowering spike of this extraordinary plant. Even then the flower spike came from Tresco in the Isles of Scilly. Since puya flower only once in their lifetime before the plant dies, and you may have to wait up to 30 years or more for this to occur, you can see the problem with exhibiting this plant at any show!

These plants will only grow outside in the warmest, hottest and driest coastal locations with any chance of flowering but flower outside they do in Penzance, Falmouth and at Ventnor Botanic Gardens in the Isle of Wight. The two species of this bromeliad from the rocky slopes of the high Andes in South America which are most likely to succeed in coastal western gardens are P. berteroniana (blue-green flowers) and P. chilensis (yellow-green flowers).

Puya berteronica

Puya berteronica

Puya berteronica

Puya have rosettes of upright light green leaves becoming more outspread with age. In maturity these can be at least 30in long with nasty barbs. For a plant to be mature enough to be capable of flowering it needs to be 4-5ft across. Then a huge trunk will emerge topped by a huge 3ft cluster of numerous flowers in loosely branched panicles. After flowering the flower head, and indeed the whole plant, dies off after the exceptional effort of producing such a vast flower spike. There will however be many offset plants around the base or in the clump which the flower emerged from and the seed are easily germinated if sown in the autumn or spring in a frost free greenhouse.

Puya will tolerate a few degrees of frost with no ill effect but they are really greenhouse plants best grown not in pots but in an open and upraised bed. Waterlogging and over watering is the quickest way to kill these succulent plants. At Renshaw gardens near Sheffield puyas are doing well in a warm conservatory set against a well drained sunny wall. If growing them outside they need to be on a raised bank in full sun but with wind protection.

Even if you never manage to flower your puya the foliage effect is good enough. If you can grow yuccas and agaves successfully you can probably attempt puya outside too.

Puya berteronica

Puya chilensis

Puya chilensis

Puya chilensis

Puya chilensis

Puya chilensis

Puya chilensis

Puya chilensis

The following is an email conversation about Puya and Feijoa.

Initial email from Paul D in Saltash, Cornwall, to Cressy.

I think your website is over-pessimistic regarding hardiness and flowering of these and I hope that you find the following comments useful.

For comparison to Burncoose my elevation is 100 m on a hilltop, 2 km from the Tamar estuary and 15 km from the coast - midway between Dartmoor and Bodmin  Moor.

Previously I gardened on Anglesey, again at 100m, overlooking the Menai Strait and facing Snowdon - very exposed to easterlies.

Puya chilensis

Provenance of the plants is important with those collected at higher elevations likely to be hardier.  When I moved back to the Tamar Valley in 2008, I was given a P. chilensis as a 'garden-warming' present.  The plant came from Everton Nursery near Lymington.  It was planted in the same location shown in the flowering picture attached (2 m stick for scale).  This plant had only formed a single rosette when it flowered 9 years later and it died after flowering.   

20-25 years ago I purchased 2 plants from Burncoose, kept them in pots and divided them when they formed basal shoots.  These 2 plants were planted on the side of a rock outcrop and were thriving when I left Anglesey.  4 of the divided plants came back to Cornwall with me and were planted 14 years ago.  Some shoots were killed by frosty conditions with strong winds but the plants survived -7°C or lower and all produced strong side shoots.  The first plant  flowered 11 years after planting,  the second 13 and again at 15 years (a different shoot)  and the third at 15 years.  Thus I have 2 flowering spikes this year.

I saw the clump in the Abbey Gardens this year and I would estimate that the flowering shoots there were about 2 weeks ahead of mine.

I also have P. mirabilis (seed grown).  This often has the leaves killed by frost but it produces fresh ones and has flowered.

Feijoa (Acca)

Both "Mammoth" and "Triumph" are producing flower shoots.  They are in a sheltered position exposed to midday sun but in the lowest part of the garden that gets frosted first.  They survived -7.5°C last winter with no damage.  I picked the remaining fruit in mid-December before a -5° frost was forecast.

My seed-grown plants are also producing flower shoots and I will use these for cross-pollination.  These plants are very hardy.  Some form a small hedge (see picture) about 3 m high now (the stick is 2 m) and I have others fully exposed to the south-westerlies - none have been damaged.  The flower petals are used in salads but the fruits are small and do not mature before the frosts.

With best wishes,

Paul D.

Email reply from Charles Williams.

 
Thank you for taking the time and trouble to send us all this information which with your permission I would like to make public on our website, particularly in relation to these two plants.

Each summer I visit Ventnor Botanic Gardens to admire their Puya and I often come back with some seed. We did once have Puya chilensis flower on our stand at Chelsea but this was cut for us on Tresco as we had a joint marketing initiative with them that year.

I have to say I have twice tried planting Puya here in the best possible dry and hot location I can find at Caerhays – on both occasions they didn’t last long.

My own view is that the location of the Puya producing seed may have a lot to do with the subsequent hardiness of its seedlings & I think a degree of luck maybe involved with this, and the weather as well.

Response from Paul.

Thank you for your email that was forwarded to me today.  You are welcome to include any of my comments on the Burncoose website, since I am keen to see more of these plants in the SW.  

I am surprised that you have not succeeded with Puya at Caerhays.  My stock was purchased from Burncoose in 2008 or 2009.  I do not know if you have had plants of different provenance since then.  Seed from plants growing at 900 m are likely to produce the hardiest plants.

Do the Ventnor plants pollinate naturally or were they hand-pollinated?  I have had no seed produced to date, although there are plenty of insects visiting the flowers, none of the native passerines are interested..

My plants were planted in a raised bed with well-drained soil.  The greatest danger is wind-chill during hard frosts.  Until the plants were 1 m high I protected them with scaffolding netting during frosty conditions.  Once the plants were larger the outer leaves on the rosette protect the growing point .  At this stage, the outer leaves may die after hard frosts but the centre of the rosette will continue growing and slowly build enough reserves to form a flower shoot.  

I have grown P. coerulea from seed and this appears to be hardier but the only one to flower to date was a small plant, with a single rosette, that did not survive flowering.

I have had no frost damage to any of my seed-grown Feijoa during the last 20 years and think that they would make a good hedging alternative to Escallonia 'Red Hedger".  They have the advantage of edible flowers and are not as vigorous so do not need cutting twice a year.

• PUYA
• PUYA berteroniana
• PUYA chilensis
• PUYA venusta