Thursday, July 24, 2008

Clean shaven caterpillars?

The boys are back. And I was wondering where they'd got to. Whereas by this time of year
the caterpillarium is usually fully inhabited, this year I've not even had to think about it. Until last week that is.

Apart from the dreaded geranium bronze butterfly (cacyreus marshalli) we only really get two types of caterpillar on the balcony, which I suspect are cabbage white larvae. One is the one in the photo above. What is it? The colours are right for the large cabbage white, but it lacks the bristles that all the photos on the net seem to show. We do have a lot of white butterflies around, definitely of the Pieridae family, but the marking isn't quite that of the ones that I've seen illustrated. The other type of caterpillar is green with yellow markings, but doesn't seem to have been around this year at all. Again, it would appear to be very similar to the small Cabbage White, but without the bristles.

Butterflies do, however, exhibit regional variations so I suspect my identifications are correct and its just that Italian caterpillars are clean shaven. Italian men don't go much for beards either, so its obviously a cultural factor.

Anyway, I found the lad in the first photo, plus seven of his brothers and sisters, happily chomping away at an antirrhinum plant. Six are visible in the photo above - can you spot them? In comparison with last year's invasion, when they just about decimated the balcony, this lot are no problem. The plant had finished flowering and I can afford to lose it, so I've left them where they are.

The Geranium Bronze butterfly caterpillar is another matter however. These are definitely not clean shaven but short, squat and bristly. And a sort of odd lozenge shape. But by the time you see them it's too late. The young larva starts life by burrowing into the stems and eating the plant from the inside - see the tell-tale hole?

By the time it emerges as a full grown caterpillar the damage is done. The whole stem has been destroyed.

They're native to South Africa but arrived in Europe twenty years ago and are now widespread over southern Europe, while northern Europe is trying desperately to keep them out. The colder climates in the north may help to stop them spreading, but here they're a plague. I haven't got a plant that's not affected this year. There was an article in the paper the other day saying that geranium sales are down dramatically this year. The article was trying to put it down to the economic recession, but rather contradicted itself by saying that petunias and other annuals are holding their own. I wonder if it isn't just that people are changing away from geraniums because they just get too damaged and tatty. The butterflies are pretty little things, but give me the cabbage whites any day.

Explore some more ...

Cacyreus Marshalli, from the UK Department for the Environment, Food, and Rural Affairs

Friday, July 18, 2008

Gardener's Bloom Day : Mirabilis Jalapa

This month's GBD post (a bit late - sorry) focuses on a plant I've grown for the last three years, and which has become a firm favourite - Mirabilis Jalapa. Originally from South America, it's been known in Europe for the last five hundred years. It's a plant which has a thousand and one common names - you probably know it as the Four o'clock plant, but it's also commonly called Beauty of the night or Marvel of Peru amongst other things in English, while the Chinese apparently call it the Rice Boiling Plant or Shower Flower, and in Hong Kong it's Purple Jasmine.

It's a sun loving plant which can't take cold temperatures, and is therefore often grown as an annual. However, although it will die down in the autumn, the tubers can be lifted and stored, much like dahlias, or if it's not too cold just left where they are. This year I grew some plants from last year's tubers and others from seed, starting both off at about the same time. The tubers have come on far faster and are now in flower, while the others are still fairly small. If you do plant from seed, try soaking the seeds for a day or so before you put them in. They germinate far faster.

The plants grow to about 3ft, and don't seem to have any particular requirements as far as soil is concerned, though one site I found suggested they like slightly alkaline conditions. That would explain why they do so well for me, as the water here is very hard, and I have problems with lime-hating plants. They need a lot of water, and wilt immediately if they get dry. However, despite looking very dramatic, they do pick up again well once they've had a good soak.

The plants put out copious quantities of flowers, which can have a wide range of colours and are sometimes variegated. They're set off well by the bright green leaves which are half the attraction of the plant. The flowers are well known for the fact that they don't open till the evening - hence many of their names - but the other intriguing thing about them is that they will often put out different coloured flowers on the same plant. It hasn't happened yet this year, but here's a photo of one I had two years ago.

The flowers only last a day, but are replaced by others immediately. Large seeds then form, at first greeny yellow but maturing to black, again providing an attractive contrast with the foliage.

In a garden the plant will happily self seed, but if you don't want it to it's easy to collect the seeds for storage (if time consuming because of the quantities). If you have small children around, however, beware. The seeds, which look temptingly like little sweets, are poisonous - as are other parts of the plant.

Being poisonous hasn't stopped it having a long history as a medicinal plant however, as it also has antifungal and antiviral properties (don't try this at home). Various chemical compounds extracted from the plant are now used commercially as the basis of products combatting viruses in crops such as corn and potatoes.

This probably explains why they are one of the few plants that I've never seen affected by pests and diseases. While all else is succumbing to the red spider mite or powdery mildew, the Four o'clocks plough on bright and healthy. Which for me guarantees their place on the balcony any year.

Explore some more ....

Raintree Nutrition

Rainyside Gardeners

Sunday, July 13, 2008

Bill is no more ..

Bill is no more. He has copped it, kicked the flowerpot. He is, as Monthy Python would have it, an ex-marigold.

Those of you who were following the saga of Bill and Ben the Flowerpot Men will know that the deceased was one of the plants taking part in my Crocks or no crocks? experiment. Which of two plants would do best, one in a pot with and the other without drainage material, all other things being equal?

Well, for about five weeks both of them were doing fine, though Ben (no crocks) definitely had the edge. June was cold and rainy, but they seemed to like it and were both increasing in size and blooming. And then July arrived and almost overnight we went from average temperatures of 16°C (61°F)to 35 (95).

We all just flaked - people and plants alike. Only the whitefly and the red spider mite could be heard yelling Yippee! and they moved in with a vengeance. I've spent the last ten days pulling off dying leaves, misting and spraying, but with mixed success.

And the other day I went out to find that both Bill and Ben were affected, and that Bill was succumbing fast. I treated them both, but for poor old Bill it was too late. He went downhill rapidly, and there was nothing I could do but try and keep him comfortable in his last days. Ben is also a bit the worse for wear, but seems to be fighting back valiantly.

So there we have it. No crocks seems to have won. Though Bill started out very slightly larger than Ben and with one bloom on the way, Ben soon took over on all counts : he grew more rapidly, gave more blooms, seemed more resistant to pests, and recovered better from their attacks.

Statistically completely non-significant of course, and who knows if the same would be true with a different shaped or sized pot which drained less easily. But good enough evidence that I will no longer panic when I'm potting up and find I've run out of drainage material.

Tuesday, July 08, 2008

Guerrilla Gardening in Milan

My favourite example of guerrilla gardening in Milan is along the tram lines just outside the centre of town. In Milan the trams mostly run along the roads -or rather don't, because the Milanese habit of double parking on bends usually means that at a certain point the trams find they can't pass. And if one tram gets stuck, the one behind does too. And the one behind that, and .... So you not infrequently find a little row of ten or so trams patiently waiting for the tow-away truck to turn up and remove the car whose bright spark of an owner decided to park it too close to the tram lines.

However, in the few instances where the roads are wide enough, the trams have their own lane down the middle of the road, with the tracks going in each direction usually divided by some scrubby, weedy grass and the odd tree.

And a few years ago, in one of these areas, some hollyhocks suddenly sprang up. There's no way they could have got there by chance - someone must have planted them intentionally. And every year since, they've multiplied, so that they now spread about 50 yards along the tram lines. Have they just self-seeded or does that same guerrilla gardener go back each year to collect the seeds and plant them again a bit further along? I suspect so, and if s/he goes on, in a few years they'll be stupendous. At that point the tramlines run for about a kilometer before they hit the road again, and a line of hollyhocks extending all the way along would be glorious.

My own hollyhocks on the balcony have done quite well this year, but the colours have been disappointing. They were supposed to be mixed, but the majority came up white, with just a couple of pinky ones and one beautiful deep red variety. The white ones would have been nice if they'd been mixed in with brighter colours, but whole containers of white were a bit boring. Nice for scanner photos though.

So despite my intention to grow them as perennials, I think I'll take most of them out at the end of the year and start again. They're full of seed heads though, and it would be a pity to waste them. Maybe I'll take a walk along the tram lines ....

Sunday, July 06, 2008

Am I going colour blind?

One of my investments earlier this year was some Calla lilies (Zantedeschia). I've had one for four or five years now, but although each year it gives me a beautiful display of lush spotted leaves, I've never yet had a flower. It's one of the large varieties and the flower should be white if it ever arrives, but I also like the smaller, coloured ones. So this year I splashed out on a deep, deep red variety and a bright yellow one. And here they are. This is the deep red one .... Don't those colours grab you?

Unfortunately I must be going colour blind, because all I can make out is the very, very slightest red blush around the tips of the petal - it's probably embarassment.

OK, they're still lovely and have been one of the things I've enjoyed most over the last few weeks. But it still drives me mad that descriptions on packets are so often false.

Ah well, I suppose life would be boring if it weren't for the occasional little surprise ....

Friday, July 04, 2008

You have to promise not to laugh ...

You have to promise not to laugh .... OK? I'm proud. Over the last couple of weeks I've been harvesting my first ever balcony-grown vegetables. Here they are - all six of them.

I said, don't laugh. And anyway they weren't the only ones. We've had another six since then, and there at least six more on the way. OK, OK - we've not quite reached self-sufficiency and the supermarket hasn't gone out of business. But it's a start. And I really was ridiculously proud of myself. They were cooked together with a large portion of self-satisfaction.

The vegetable garden is still coming on, but I'm having a few problems with the sex life of my zucchini (you're not laughing, remember?). They're blooming like mad, but they're the most prudish flowers I've ever come across. They seem to spend most of the time firmly clamped shut, apparently with the same attitude to reproduction as the headmistress of a Victorian girls' school. And then, I can't tell the difference between the male flowers and the females. I'm out there daily with my little paintbrush playing at being a bee - but if the bees know what they're supposed to be doing, I certainly don't. Just spread the pollen around a bit, that's my motto. With any luck sooner or later there'll be a telltale bulge, but if anyone knows of any clear photos on the net which show the difference, do let me know. I've been staring mystified at fuzzy pics which state authoritatively that they show the male or female flower, but they look just the same to me.

Everything else edible has succumbed. The salad leaves collapsed, the oregano turned brown and died, as did the rosemary, and the mint and basil have been devoured by caterpillars. And that's just the vegetable garden. Oh well, the false security of the long, cool spring is obviously over. From now on it's back to hot, sticky pest and disease-ridden summer reality ....

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