Gus Evans is now retired but for many years ran his own nursery at Waikanae on the Kapiti Coast, where he grew swan plants. Read about the adventures he had:
Swan plants? We grew them for over 40 years. I always said swan plants are like alcohol and cigarettes … I know you will be back for more!
We grew them in a totally covered house to avoid monarch attacks. But apart from monarchs, pretty much the only other thing that ever bothered them was the little orange aphid, Aphidius nerii.
Our top tip to people was, at the end of the season, to plant 3-4 close together and make a total shade cloth cover over them to allow the plants to grow into something quite substantial and be able to sustain the first invasion of caterpillars in the new season. The cover needs to be large enough to not touch the leaves on the plants as butterflies could lay on them.
An old guy who lives not far from us had an old swan plant that had a real stem on the bottom of it – I would say about six or seven years old. Maybe you’d call it a ‘trunk’. Every year that could sustain 600 caterpillars at any one time. It was massive, and every year totally covered.
We built up a real clientele over many years. Garden centres and the public trusted us implicitly that our plants had never been sprayed. For that reason, we had huge pre-orders year after year. We grew the same amount every year, about 6,000 in 1.5L pots. We would plant three per pot, so customers got their money’s worth and were satisfied.
We would give away many to schools and kindergartens (until they were notified it was poisonous), and people we knew who loved them but couldn’t afford it for their kids. How many kids have you seen eat swan plant leaves? Yet in our laundry sink cupboard we have far more potent dangers.
Over the years we have shared so many monarch stories. People make such a hobby of raising monarch caterpillars. One Christmas Day I got a call from a lady who said her monarchs had run out of feed, and could I open up, and get her some urgently? We did!
The funniest story is this: One year a large garden centre asked us for 600 plants with the proviso that each plant would have a caterpillar. No problem, I thought. I put them all outside about a fortnight before delivery, and sure enough heaps of caterpillars!
So, we dutifully set about putting a caterpillar on each plant. However, on the journey into Wellington they decided to migrate all over our van. The caterpillars were on my neck, crawling up the windows, on the roof … everywhere. Amazing! When I arrived, I said to the boss lady, I have good news and bad new.! The good news is there are all your plants but … there are all the caterpillars. You are going to need to grab them.
It was hilarious, all their staff coming out and re-introducing all the caterpillars to the plants.
We have met so many interesting people over the years sharing the love for monarchs. One lady would buy hundreds off me every year but insisted on picking her own plants. For maybe 100 plants she would spend at least an hour. She used to crush the orange aphids in her fingers. We used to drown them by immersing the plants in a deep bath, eliminating the use of sprays, which was the golden NO NO! She used to discuss with me breeding first and second-generation monarchs.
Another funny story was when we first got into swan plants, the first time we potted them up was outside. We went for lunch and when we came back, they had been invaded. Eggs everywhere. We spent many weeks picking off caterpillars, as the damage they caused with their voracious appetite made the plants unsaleable. Lesson learnt: only pot inside in future.
Pretty much it is very expensive to buy small plants every season as within two days the plants are stripped bare and we have hungry caterpillars. Some people even cried that the caterpillars were hungry, such is the emotional attachment people have to monarchs.
Try hard to grow some big plants to sustain the attack of the monarch butterflies. If you have been buying small plants each year, check out the tips on the website here and see if you can modify your garden to accommodate larger swan plants.
Here’s Gus secret to growing his plants:
We always sowed seed. We always used Daltons Seed Sowing Mix, lightly covering the seed. We would start sowing our first batch in July, and every month afterwards, with the final sowing in November. That way we had continuity and guaranteed ongoing supply.
We would put the seed trays on bottom heat for germination. When they had germinated, we would prick these out in about three weeks into 5 cm tubes, and then finish them off in 1.5 litre pots. It was essential to have good light after germination so as not to draw the plants and make them spindly.
After they were potted, they would be for sale at about 800 mm high in seven weeks.
We never fertilised again as it was a quick crop to produce, but it is essential to use a top-quality potting mix with all the good fertilisers in it, such as Daltons Potting Mix. The cheapest mix is not necessarily the best.
Sometimes yellowing may occur. For us this would be caused by overwatering as there was definitely no nitrogen deficiency. Perhaps if established plants are turning yellow, they may need some good slow release fertiliser around the drip line.
We would feed the plants twice a year if outside, and as a rule of thumb feed them as they are going to sleep (say late March) and again as they are waking up in September.