In April this year I planted a number of artichoke tubers in a previously neglected site. For the site's history, click here.

Its now July and the tubers are growing well- yet look at the difference in size. The black marks on the bamboo cane are 0.25m apart and the yellow plastic strip is 1m above ground level. All the tubers originated from the same stock-and being vegetatively produced should be genetically identical.

Your task to suggest explanations, frame a hypothesis and describe how you would test it. You can find ample background material by clicking the links. Send me your ideas by email.

Plot 1

Now look at a plot about 5 metres away

Plot 2

Jerusalem artichokes Helianthus tuberosus produce edible tubers ready for the autumn. They are perennials (crop every year)believed to originate from North America(not Jerusalem!). They should not be confused with Globe artichokes Cynara scolymus which produce huge edible flower heads-delicious boiled or steamed and served hot, drenched in butter!

Jerusalem artichokes are undemanding plants - a worthy alternative to the better known potato which needs so much fiddly preparation and care. But they aren't just easy to grow; they are absolutely delicious (see recipe) to eat. Why? Firstly their texture- cooked properly they are like water-chestnuts. Secondly their taste- sweeter than a potato due to the fact that the carbohydrate in artichokes is in the form of fructose(derived from inulin)... spuds have the blander starch.

The foliage can grow as tall as 3 metres in the season-even in the UK. Giving them a rich soil is counterproductive-you get lots of lush foliage but little tuber biomass.

The ground was previously occupied by a row of established and large Leylandii trees. These were cut down to ground level last Autumn and the stumps left to rot. You can see that the plants in Plot 1 adjoin a large barn formerly used for chicken production.
Incidentally our neighbour had a parallel and even larger row of Leylandii which were also cut down to ground level. In between the two rows of trees was a sound six foot high fence of fencing panels - take a look at them.
Back to the text

<

The stumps show no signs of deterioration or rotting so far. Stumps and roots therefore remain.
Back to the text

As soon as the trees were felled the fence started to experience wind damage and several panels and posts were blown down. The fence was our neighbour's and he has now moved.
Back to the text

Many coniferous species are associated with mycorrhizae.
Back to the text

Soil dwelling fungi form an association with the roots, providing the trees with large amounts of inorganic nutrients from the soil. A similar feature is found in other plants where nitrogen fixing bacteria (e.g. rhizobium) fix nitrogen and pass it to the plant as nitrate.

Soil samples have been tested at several places within the sites. There is absolutely no difference in levels of nitrate, phosphate, pH and potassium throughout the growing areas. Moisture levels are also similar throughout.
Back to the text

There are simply loads of recipes on the web! The secret is not to overcook-they are delicious slightly crunchy. They can be boiled, roasted, sautéed, souped, pureed or even eaten raw. Some authorities say that they are better for you than potatoes because we cannot digest inulin as well as starch. This can lead to flatus- so don't eat them before or during that special date! Here's a favourite winter recipe of mine- a good accompaniment to roast chicken:
Artichoke veloute
750g artichokes
2-3 medium onions(depending on taste)
250ml water
2 tomatoes(or use tinned,drained)
butter,flour, milk to make 250ml white sauce by your favourite roux method.
Teaspoon of chopped parsley
Bayleaf

Wash artichokes, peel and cut into walnut sized pieces.
Peel but do not chop onions.
Place onions,artichokes and bayleaf in a pan with the water and half the milk.
Simmer gently for 15-20 minutes in covered pan.
Concasser tomatoes(fresh)or drain and slice them(tinned)
Melt butter in a saucepan, add flour and bubble gently for 2 minutes.
Strain on half the artichoke liquid and warm through while stirring to a lump free consistency.
Add remaining milk and simmer gently for a couple of minutes stirring continuously. Add salt to taste.
Discard onions and bay leaf, add artichokes, tomatoes, parsley to sauce.
Simmer a couple of minutes before serving.
Back to the text

The largest plants adjoin an old chicken shed.
Back to the text

Back to the text

A joint of smoked bacon, some water, artichoke slices,carrots,onion, bay leaves,mixed berbs and peppercorns. All braised in a closed casserole at 200 degrees C (180C in a fan oven) for 90 minutes.
Served with parsley sauce and jacket potatoes. Perfect for a cold winters day!Back to the text.