Growing Avocados

This summer, I've been growing avocados. Not a great challenge - they're dead easy. The question is, whether they're worth it.

Avocados are a rain forest plant. They've evolved to survive as seedlings under a canopy of leaves which blocks out the light. How do they manage? By putting all their energy in to growing as tall as possible as quickly as possible to reach the light. Result - a tall, spindly plant with a long thin stem and a cluster of large leaves at the top. Not desperately attractive as a houseplant or balcony plant. I've had them before and, quite honestly, they ended up looking dreadful.

But I thought I'd see that I'd try again and see if I could keep them lower and bushier. How ? First of all by making sure they have plenty of light, so they don't feel the need to become ganglier than necessary. But I've started off two pots, and they're each going to get slightly different treatment.

Pot number one (top photo) contains seeds that were started off at different times - the tallest went in at the beginning of the summer, the last one yesterday. Starting from now with the two tallest, I shall pinch out the growing tips to encourage them to spread. And I shall start pinching when each one is slightly smaller than the one ahead of it. That way I'm hoping to get bushy growth at different levels - the lower ones masking the spindly trunks of those which are taller. Well, that's the theory...

Pot number two has three seeds. They've just gone in, and as they grow I shall braid the trunks just as you often see done with Ficus benjamin. I'm hoping they'll eventually fuse together (as Ficus benjamin does). But in any case, the effect should be less height (because each trunk has been wound around the others), an apparently thicker "single" central trunk, and a mass of leaves on top. Again, that's the theory. While I can find plenty of advice on growing avocados on the web, and also plenty of advice on braiding other trees, no-one seems to have thought of putting the two together. Or perhaps they have and it just doesn't work. We shall see ...

If you want to grow them, use a fresh seed - plant it almost as soon as you eat the fruit. Let the brown outer coat dry and peel it off. Then just pop the seed into some fertile soil, broad side down and with its nose just showing above the soil level. Keep the seeds moist (not soggy) and wait. Forget all that stuff about sticking toothpicks into them and suspending them over water - would you like toothpicks pushed into your tenderer parts? Just plant them in the pots and keep them warm - I've seen around 20°C (70°F) recommended, but mine have zoomed up this year in temps of around 27°-35°C (77°-90°F). They are rainforest plants, after all.

Then you need to be be patient. It will seem for the first month or so that nothing's happening. Not true - they're developing long thick roots. This is one that I pulled up yesterday because after waiting for weeks and just seeing it get drier and harder, I did decide it had died. But you can see that a long root had already formed before it gave up.

So wait. And then, sometime in the second month, you'll see that the top of the seed has split, and very soon the stem and the first leaves will be poking through. And growing at a rate of knots. Keep them moist (but again, never waterlogged) and feed regularly with a fertiliser containing balanced nitrogen, phosphorus and potassium and also zinc.

Size can also be controlled by trimming the roots annually and keeping them in a small pot, but the size of the leaves means that they're not really suitable for bonsai treatment. Huge leaves on a tiny tree would just look daft. There are dwarf varieties, but I don't think you're likely to find them in your local supermarket.

Avocados are not hardy. Once the temperature drops below 7°C (45°F) they need to come inside - which may become a problem if they do get really big. Cold may also kill the seeds too, so don't store the fruit in the fridge before you plant.

But then, you wouldn't be silly enough to put fruit in the fridge and destroy all the vitamins anyway, would you? And avocado has lots - it contains vitamins A, some of the B group, C and E and is also full of minerals : it has three times more potassium than a banana, weight for weight, as well as calcium, iron, magnesium and phosphorus. And despite it's high fat content, it's mostly mono-unsaturated fats and is low in cholesterol. (1) What more do you want?

Sadly, though, the only avocados you get to eat as a result of growing them may be the ones you buy in order to get the seeds. Sources differ as to how long it takes a tree grown from seed to bear fruit - around ten years seems to be the average estimate (2), but some websites put it at as long as twenty. Don't think our local supermarket need feel too threatened ...

References

1. The California Avocado Commission
2. Flower and Garden Tips

Form and Colour, Colour and Form

Whoops - how to lose friends and alienate people. I didn't mean to, honest, but some of you obviously thought that my last post was intended as a rant. It really wasn't and I've tried to explain why in the comments, but I'm sorry if I offended anyone. For the record, I have absolutely nothing against the people who created those balconies or against anyone who has the same attitude to balcony gardening. They're wonderful, and certainly contribute more to making the community attractive than mine does.

But as an attempt to redeem myself, I thought I'd talk about how I do try and create visual impact with containers, while at the same time growing as wide a variety of plants as possible. All my containers are different, but within each container I try and achieve an effect either by combining different colours and/or different forms.



Here's an example from a couple of years back. Very simple - marigolds and yellow surfinias -but it worked wonderfully. The stark browney-gold of the marigolds both contrasted with and complemented the lemony yellow of the surfinias, as did the different forms of both the flowers and the leaves. And they're both set off by the little white daisies peeking out from behind.

This year my most successful container had flowers of one colour only - but with completely different forms : surfinia again and sage (though I'm ashamed to say I've forgotten which one). The photo doesn't really do it justice - the purple spikes of the sage towered above the trailing surfinia, and it looked superb, both from below the balcony and from behind.

I love purple and have a lot of it on my balcony. In this photo from last year, purple and white surfinia mix with pink antirrhinums and blue plumbago (all grown from seed except the plumbago) - again creating harmony and contrast of colour and form.

Purple is one of the few colours I really like using together with pink - especially dark pink. This photo was taken early after planting - imagine them when they'd grown and filled out the spaces.

So my balcony's a hotch potch. I also admit that I usually plant thinking of the view from inside rather than below. And these photos range over three years and were, admittedly, taken when things were looking good. They hide the tatty failures. But I still think they stand up to the ones in the last post, stupendous as they were. And I promise you they're more fun to grow.

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.

What a difference some flowers make ...

One of the comments I get fairly often here is You must have a really big balcony. But I don't really think I have a lot of space. Disregarding the office balcony, where I've only got a couple of containers, here at home I have two balconies - each 10x1m. Twenty square metres in all - not really a huge amount of space.

But it's enormous in comparison to what I'd have if I lived on the ground floor. Whereas from the first floor up every flat has at least one balcony, on the ground floor they only have a windowsill.

Welcome to Colditz.


But one of my neighbours has proved that you can have a garden even in the most limited amount of space. The windows in the photo above are on the right as you face the front door. Here's the identical view to the left.


What a difference a few flowers make.

Old crocks? Not on my balcony ...

Open any book on container gardening, and you'll soon come across a stern admonition about always adding a layer of old crocks to the bottom of your containers to assist drainage. If not, the received wisdom goes, the drainage holes in the container will get blocked by soil, the soil itself will get waterlogged and your plants will die.

Sounds logical. So why is it, I always wondered, that whenever I get plants from the garden centre there is never, but never a layer of drainage material. There may be perlite of sand or something mixed into the potting compost, but at the base nothing. And yet the plants are healthy, happy and show no sign of being waterlogged at all.

So I was intrigued to find this article in the Horticultural Myths section of Linda Chalker-Scott's website. Chalker-Scott, who is an Associate Professor of Horticulture at Washington State University, argues that far from aiding drainage, the broken potsherds, gravel etc usually used will actually prevent it, and leave the soil more rather than less waterlogged.

According to Chalker-Scott this has been proved by a number of studies. Annoyingly she doesn't provide references, so there's no way of checking. But I thought it would be fun to try an experiment and see what happened.

So today we have the great Balcony Garden Drainage Material Experiment. No claims to being scientific, but here's how it goes. Two identical 10cm pots, one with old crocks and large clay granules in the base, the other without. Both are then filled with the same potting compost, and the same amount of water is added - enough to more than waterlog the soil.

The liquid that drains off immediately and after half an hour is measured and, lo and behold is exactly the same.

However, as the whole point is to see how this affects the plants growing in the pots, there's a second stage. Two marigold plants, as nearly as possible identical, are added - one in each pot. I've called them Bill and Ben. Bill is in the pot with crocks and Ben in the pot with no crocks. Over the next few weeks they'll be kept in the same position, receive an equal (though generous) amount of water, and be treated in every way identically. And we'll see what happens.

Who'll grow strongest? Will it be Bill or will it be Ben?