Agriculture in Japan is a continual race against time. There are a number of factors which appear to create this situation. It is an extremely fertile country. If a mountain forest is cut down it will quickly regenerate. Some of the logs and stumps I have seen have incredibly wide growth rings indicating rapid growth per season. But apparently it is bamboo in all it's varieties that farmers have been at war with for eons. The giant bamboo in our neighbourhood produces new shoots (takenoko) in spring which shoot up more than ten meters in a season. As the shoots appear the previous years bamboo leaves turn yellow, then beige and fall in spring. The bamboo is a very useful plant for structural and other purposes, but if ignored will turn the farm (hatake) into a bamboo forest.
In winter the weed I call creeping Charlie with its spindly stalks and purple flowers covers whole fields in the winter in Ibaraki ken. Although not a large weed unless controlled it will inundate the winter crops. At first I thought this was the farmer's worst enemy, but along comes spring and an army of weeds arises from last year's seeds. Never let your weeds flower! Roots are bad enough. There is never enough time to control all of these weeds. Japan has many plants such as the kudzu vine (legume plant) and knotweed which apparently have enough competition from other plants in Japan that houses are still visible here. Fools have transported these to North America where they cannot be controlled and homes are being swallowed up.
I saw them in the garage and wondered why they were not being used? Creeping Charlie is nothing, when spring comes, out come the brush whackers. These are much like a heavy duty weed whacker in North America, but they have a variety of cutters that appear to be similar to circular saw blades. Always check your ankles after using these! Every self respecting male in the rural scene has at least one of these. It skips over the ground in wide sweeping arcs in front of you cutting everything except woody materials down to near ground level. Let's not worry about the plants, they will grow back. In areas where these are not used, I am not sure whether I would be able to walk across the vine entangled 'pasture'. I suspect that if one stood still for an hour near a kudzu vine, it would have you secured in its clutches.
Agricultural plants need to be fostered to enable them to keep ahead of the weeds. How can farmers stand the frustration? In central Canada there is one growing season, but here it is continuous with no respite. Weeds are a minor nuisance, you should see the hosts of insects that come alive in spring to devour everything before harvest or so it seems.
The rows of cabbage and broccoli were carefully weeded and later when evidence of worms was seen on the outer cabbage leaves, hours were spent plucking these off and destroying them. This was a colossal waste of time. The broccoli and cabbage crops are a total write off. I propose that netting to prevent the cabbage butterflies from laying eggs might have prevented the catastrophe. Anyway I am not the expert and poisons are being avoided as much as possible. I was hoping the plants would grow faster than the worms could eat them, but the worms quickly migrated from the outer leaves to the cabbage and broccoli heads. The snow peas had already been planted when we arrived in early March and grew slowly until the last few weeks when they flowered and produced delicious flat pods. But almost immediately at this stage I noticed that leaf miners were burrowing their way through the leaves. As a result the snow pea season was much shorter than I would have liked. The potatoes everywhere in the village flowered nicely and looked very healthy and then along came a blight and decimated most of the plants. Let's hope the potatoes had enough time to grow underground.
Currently the many chestnut trees in the neighbourhood are flowering long feathery yellowish tassels. At this stage the chestnut trees can be recognized half a kilometer away. These trees were introduced to North America and brought disease with them that the North American chestnuts had no immunity to. In Japan the trees become ill, but tend to survive long enough to be productive.
Because so many areas of productive farmland in Japan hardly ever freeze, particularly on the eastern coastline crops can be produced almost year round providing fresh vegetables for the country. The western coast and northern parts of Honshu and especially Hokkaido have snowy cold winters. This provides opportunity and competition for other areas to provide food. So besides battling weeds and insects, farmers are also competing with each other to produce crops quickly and bring them to market quickly.
I suspect that this battle against time has been one of the strongest influences promoting the use of plastic ground covers and greenhouse plastic tunnels covering rows of plants to retain heat and speed growth. Full size greenhouses are seen everywhere in Japan and are used to start seedlings such as rice as well as grow crops to maturity. Strawberries grown commercially are usually grown in greenhouses covering hectares of land. Japanese television is documenting how farmers are migrating to factory style hydroponic greenhouses to grow plants such as lettuce. What happens next?