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Late bloomers and allelopathy

Normally here on the south coast the summer stretches on into September and even October, but this year Autumn set in promptly with high winds, lower than normal temperatures and leaves starting to fall.

Despite this many of my summer plants remain in flower, and with the higher temperatures returning in between storms a few of my spring flowering plants have been fooled into a second flush of blooms:

Top to bottom and left to right: berberis darwinii, rose, orange flower, choisya sundance, rhodedendron, rosemary

September saw me picking the last of my tomatoes, and my courgettes are no longer developing, but my potatoes and runner beans are still going strong. I've also got figs and autumn raspberries:

A Problem with Allelopathy

A large area of my garden lies beneath my neighbour's huge Monterey Cypress tree. As stated in the Earth2Art blog ( "Monterey Cypress ... is extremely allelopathic. It has been my experience that  there are practically no plants that will survive more than a couple of years within the root zone of a cypress.  Furthermore, being a coastal tree that relies primarily on fog for its moisture, the Cypress creates a dense mat of tiny roots just under the soil surface that suck every bit of water available.  Even after weeks of soaking rain, if one digs 6 inches down into the soil under a tree, they will frequently find that the ground is bone dry." This has certainly been my experience also; "allelopathic" means that it releases chemicals which inhibit other plants from growing, and I've found that plants which thrive elsewhere in the garden die or grow very sparsely when planted within the root area of this tree. The area is permanently shaded, and even after very heavy rainfall it remains dry. This, coupled with rather an ugly party wall which I want to hide, makes this a serious problem area in my garden.

I've experimented with lots of plants and the only one which seems to grow reasonably well is ivy, but my neighbour sabotages this by loosening it from the top so that it collapses. A euonymous which self-seeded in the area is showing some promise so hopefully this will continue to thrive, but it's rather slow growing so it will be a while before it hides teh wall. This month we built a new raised bed in the area; it won't help with the shade issue but hopefully it will keep new plants above the level of the root system so that the allelopathic chemicals don't affect them and I'll have to deal with the dryness by watering regularly. I've put a couple of young bamboos in there, if they grow they should do so fairly rapidly and they'll also spread to fill the bed.


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