[JTh]

Until this year we have had a local gardener, Apostolis, taking care of our olive trees, but now he has retired and a young fellow will do the pruning. Apostolis always insisted on surface-ploughing the ground between the olive trees, to keep the weeds down, it was better for the olive trees, he said. We finally managed to make him leave some ground around the house unploughed, so that we have some place to be outside the flag-stoned terrace, which was a great improvement.

I wonder if this ploughing is still the recommended practice these days? Some people insist on digging the ground around the trunk, but is this preferable to leaving the ground untouched? We used to do so with apple trees before, but I don’t think it is commonly done any longer; generally it is said that you should disturb the ground as little as possible. I would much prefer to have the ground covered with wild flowers, if it is OK for the olive trees. What do you recommend?

[Umbrian]

I have always understood that the purpose of clearing a circle around fruit trees, in particular around newly planted ones such as Olives, was to avoid competition for nutrients and moisture and enable an annual top dressing of manure to be incorporated. Keeping these circles weed free is a rather laborious job but  the end result much more attractive than ploughing everywhere.

[JTh]

Yes, I agree that young olive trees should be kept weedfree around the base to avoid competition, but I also read that 'a vigorous, mature olive tree will no longer need a weed-free radius. Simply mowing the cover crop or weeds around the base is sufficient'.

With the practice used here until now, the ground has been plowed/harrowed after the spring flowers are finished. The result has been that the ground has then had a regrowth of  almost monoculture of the horrible weed Tribulus terrestris, its handgranate-shaped spiky seeds bore into your shoes, stick to carpets and are awful to step on, I can see why it is called devil's weed. I believe by not opening the ground to these devils, the ground will have a much more balanced mix of plants, and there will be less run-off.

[John J]

Jorun, I don't know what the perceived scientific approach is, all I can relate is my own experience. 
The land between our olives was ploughed every year until after we returned to live here permanently when we stopped the practice. 1. Because I felt that it was possibly damaging the soil structure. 2. The trees were prone to being damaged by being hit by the harrow and I wasn't sure about any unseen damage to 'feeder' roots below the surface. 3. We quite liked having the wildflowers growing. I resorted instead to strimming the area once the summer heat had done its worst, leaving the remains in situ, a sort of chop and drop method of mulching. I don't believe that the trees or their produce have suffered as a result.
You may like to take a look at the following website; www.sabor-artesano.com/gb/olive-cultivation.htm. I'm not saying that I agree with anything on there but thought you might find it of interest.

[JTh]

Thank you, John, what you are writing is what I am thinking as well, glad to get this confirmed. I had already read what was written in the the link you gave, it is ment for a more large-scale operation than my 38 olive trees, the non-harrowing is at least one of the options. Using herbicides to control the groundcover is definitely not an option, but strimming the area between them once in summer is no problem, that's what we have been doing with the part that was left untilled.

Do you fertilize every year, if so, with what and how much?

[John J]

Jorun, I agree with you wholeheartedly about not using herbicides. I suppose the simple answer to your question is, I don't. Our land is flat and fairly fertile. For unknown generations it was used as grazing land for sheep and goats who, I guess, fertilised it naturally. Now I try to improve the soil with any organic matter I can lay hands on. As already mentioned the strimmings that are left in situ, leaf debris swept from paved areas, shredded material from prunings, well rotted manure from a neighbour who keeps sheep ....

[Joanna Savage]

JTh, for many years I was working in Puglia as preparations were under way for the olive harvest. The farmers  would harrow round and round in circles around each tree until the soil was a fine tilth. As I had had an Australian agricultural training, where soil conservation against water erosion was lesson one, it was quite shocking to see the loss of soil after the winter rain. There were marvellous old trees exposed to almost a metre above the current soil level. That metre would once have been root system. I often wonder how those trees are faring now that Xylella is so active.
There must have been a reason, probably now buried in time, why this practice was followed, but it is difficult to imagine what it might have been.Was the mechanisation of farming such a boost and time and energy saver that it was easy to overdo the harrowing. As I vaguely recall, Oliver Rackham gave some such explanation of deep ploughing in Crete.

[JTh]

I suppose one of the reason for this surface treatment was to reduce the risk of fire, and that may be why it was compulsory in parts of Italy, but mowing early in summer should help as well.

[Pauline]

I have an Apostolos who does an enormous amount of unpaid work for me so, despite my misgivings about what it's doing to the soil and any shallow roots, I shut up and let him plant fruit trees where there are no olives. I don't lose soil in the winter rains as it's all been terraced, simply it's not my style of gardening. But there's no way I can cope with it myself, there being far to much of it and equally too little of me. So I'm letting my enthusiastic garden helper do his thing and trying to learn to love ploughed earth. Certainly fire is a consideration here too; leaving dried-up ground-cover in situ will make you many enemies and may well be illegal.

[JTh]

Exactly Pauline, this was how I felt as well, I was afraid of insulting Apostolis, because he has been taking so good care of my olive trees. He has also grafted several wild (extremely spiny) pear trees, we now get so many pears every summer that I don't know what to do with them. But now that he's retired, I'm free to choose what to do.

[oenz]

Something else to consider. In our area of Spain it is common practice to 'clean' the area around olive trees to reduce the fire risk. The neighbours plough their land once a year. I personally prefer the wild look although I noticed in my home insurance policy recently that all 'combustible material' should be cleared to avoid the spread of fire. Knowing how insurance agents work, it may invalidate my policy (and any claim) should a fire ever break out and reach the house. I think I may need to at least get the strimmer on any long grass (whilst avoiding the wildflowers).

[Pauline]

And I forgot to mention something that everyone else does: snakes. Many people are horrified at the idea of anything that might provide any sort of cover for them. I, on the other hand, have been known to remark that my last words could well be "but I like sna..."

I'd have thought that the wild flowers set seed well before the wildfire season, so could strimming at the right time and giving the cut stuff a good shake while collecting it be the answer?

[andrewsloan]

A good discussion going on. I stopped plowing our 2 acres of olives a dozen years ago as I could see all the top soil being washed away and also wanted to walk through the olive grove especially in spring time.
Strimming works very well for me just before the summer.
 I also try and fertilise naturally by sowing vetch, rather like I believe broad beans are used in some parts of Greece, as both plants have nitrogen fixing nodules on their roots.

[JTh]

I'm happy to get so much support for my decision to stop plowing, I got an agreement with a reliable fellow who works next door, he is going to take care of  the strimming, in addition to watering the many flower pots while I'm away in the warm part of the year.

I suppose the olive trees would need some extra feeding in the winter, I had to add borax to a few of the olive trees a couple of weeks ago because some of the leaves were turning yellow.

If the summer is good and everything goes all right, then a bumper crop is expected this year, it looks very promising.

[Pauline]

I just thought I'd mention that, our enthusiastic garden helper being busy elsewhere, we strimmed the weeds yesterday. Today it rained. Hmph!