When I left Greece at the end of April, I had just applied a fair amount of manure, a soil conditioner, and had broadcast wheat in the hope that many of the bare patches scraped thin when the field was levelled in October might get the benefit of an active cover crop over summer. Returning in early August, the landscape had changed dramatically. What was a lush green in spring had turned golden yellow under the influence of the mediterranean sun. The fig trees marking the border of the property had undergone a similarly dramatic transformation, with sparse spring canopies filling in with heavy, dark green leaves and abundant fruit that will ripen to deep purple over the coming month.
What had been a short sward of freshly emerged grasses and vegetation was now a mature stand of largely summer-dormant grasses, interspersed with a broad range of volunteer species that not yet emerged at the end of April. The wheat I broadcast had only had partial success, and a fair amount of what had emerged had been grazed short by goats. That said, the broader objective has largely been achieved and enough vegetation exists that erosion is no longer the immediate concern it was after the field was levelled. The erosion holes that were filled in with reclaimed topsoil are now impossible to distinguish from the rest of the hill and were quickly covered in vegetation.
Not everything that has returned is of course equally welcome. A handful of particularly nasty thistles had grown large, while several Christ’s Thorn bushes had re-emerged from the root systems left behind when the ground was cleared. These woody perennials are particularly problematic if left to re-colonise the property and will need suppressing until such time as the energy reserves in their deep root systems are sufficiently depleted, rendering them unviable.
Perhaps more interesting than the occasional plants that need removing is the breadth of vegetation that has returned. Grasses, legumes, thistles, deep-rooted pioneers and a range of other species have taken hold on the plot, each responding to the particular conditions present. Some of these are from the existing seed-bank, while others I'm sure have been introduced since the ground was disturbed, taking advantage of the new landscape.
What I want to focus on in this update is what this diverse community of emerging plant species can tell us about the soil, how the site functions, as well as potential implications for the vines that will be planted here next spring.
If you are not up to speed on this project I suggest taking a look at the previous instalments of this Vineyard Series, which chronicles the planning and preparation of a small vineyard in Kormista, Greece, and, come spring, its planting and management.
Reading The Ground
Viewed in isolation, many of the species that currently occupy this hillside plot might, by some, be considered weeds. As a whole however they form part of a highly diverse mediterranean meadow and reflect both the underlying conditions of the site and the recent disturbance it has experienced. Areas that were less affected by the groundworks retain a plant community closer to what existed before the field was cleared. Elsewhere, particularly on the higher parts of the plot that were regrettably scraped more aggressively, early-succession species have taken advantage of the comparatively harsh, exposed ground and the lack of established competition.
The crucial distinction here is that the term “weed” is an agricultural designation rather than one that carries any ecological meaning. Every species that successfully occupies this soil does so because it has found a niche, and each contributes something to the ecosystem around it. Even so, a couple of species, while useful to the environment as a whole, are counterproductive to the goal of growing vines, and will therefore have to be managed. We have already touched on a couple, including Christ’s thorn and the thistles, but will encounter others in due course.
Grasses
Grasses are perhaps the plant category that makes up most of the visual structure of the plot. Taking advantage of winter and spring rains, they quickly establish a broad and fibrous root system that does a fantastic job of holding soil in place. Over the course of the season, these winter active grasses grow tall, produce seeds and senesce, going largely dormant during the warm, dry summer months. When compared to many commercially available grasses bred to look as green as possible year round, this ability to go dormant when water stress naturally becomes high is a very welcome quality. In practice this means that during the driest part of the year, these species do not meaningfully compete with the vines for water, while contributing soil carbon, structure and microbial habitat. Grasses like these are indispensable, and as they have naturally established, I see very little need to introduce a new species of perennial grasses myself, rather focusing on the management of the existing sward.
Among the more abundant grasses on the plot are wall barley (Hordeum murinum), bristly dog’s-tail (Cynosurus echinatus), ovate goatgrass (Aegilops geniculata), rigid ryegrass (Lolium cf. rigidum), wild oat (Avena sp.) and brome (Bromus sp.). Interspersed between these is the broadcast wheat (Triticum aestivum) which I introduced, but it is far from dominant in the landscape. This mixed assemblage of mediterranean annual grasses represents a very promising successional grass cover, with different seed architectures, growth heights and habits, none of which need aggressive management. Some, like the wall barley are biennial, and its relative abundance makes perfect sense after the relatively strong disturbance the plot experienced. As other species get more established I’d expect the relative dominance of wall barley to go down, but looking at the neighbouring plot which was undisturbed, it has formed part of the permanent ecology of the site for some time.
One downside of wall barley, which it shares with ovate goatgrass, is particularly sharp seed spikes, known as awns. These are barbed, and are able to work their way deep into the fur of passing animals. As it happens, this also means they attach themselves readily to clothing and are a nuisance. The rest of the grasses are more benign Mediterranean annuals that provide useful standing biomass and root turnover. I’m confident that this list is not exhaustive, and it will be interesting to see how the combination of grasses evolves over several seasons.
Legumes / Nitrogen Fixers
While not visible in August, the spring sward showed the presence of annual clovers (Trifolium spp.) which provide excellent low-growing ground cover, fix nitrogen and act as useful insect forage. Annual vetches were also visible in spring.
Flowering Broadleaves and Insect Plants
Perhaps where the diversity of plant species on the plot becomes most apparent is in the range of flowering broadleaves and flowers that emerge in spring, and their summer successors. Buttercups (Ranunculus sp.), chamomile (Anthemis sp.) and Borage (Anchusa sp.) are but a few of the spring emergent species, all of which are either useful pollinator resources or make for valuable early insect forage.
Later on in the season hardier plants become more dominant, with wild carrot (Daucus carota) being particularly prominent. With a deep taproot characteristic of plants in the carrot family, it contributes greatly to a healthy soil structure, and it is an excellent insect plant, with an open, shallow flower structure providing easy access to nectar and pollen, heavily attracting hoverflies, native bees, beetles, and parasitic wasps. When the seedheads mature however they create abundant and troublesome burr-like seeds that stick to clothing. Nevertheless, while it might be worth strategically mowing some of them for the ease of working the plot, wild carrots do more good than harm.
The plot also has white horehound (Marrubium vulgare), spurge (Euphorbia sp.), purple dead-nettle (Lamium purpureum), and diffuse knapweed (Centaurea diffusa). The latter is a deep rooted, drought tolerant plant that is highly compatible with calcerous ground and is a good insect resource. It is one that is worth controlling before it seeds excessively, but as it stands the amount present is manageable and given how excellent a pollinator it is I am not too concerned with it for the present.
The large thistles, possibly milk thistle, though I have not been able to concretely identify it, also falls under this category. With explosive growth and substantial taproots, these are particularly troublesome and simply must be removed. That said they are excellent indicators of a disturbed site, scavenge minerals and have value as an insect species, but these benefits do not outweigh the painful physical hindrance they represent, and I can only hope I got to them in time to prevent excessive seeds from dispersing.
Low-growing mediterranean and drought adapted plants
Few plants had taken hold of the bare patches as well as the ground pine (Ajuga chameapitys), a small pine-like plant that is particularly conspicuous on the scraped, shallow and open ground that few other plants have yet to colonise. It thrives in environments where there is low competition, excellent drainage with shallow, rocky soils and little water. In particular, it is able to tolerate a high concentration of soil carbonate, or active lime, and is as such a particularly useful as an indicator plant. That said, it is impossible to tell by its presence whether the exposed soil, having been heavily disturbed since I took my last soil test, consists of a higher concentration of active lime than the average of 15.9% that came back from my last soil test. While I’m confident that 1103P, one of the rootstocks I've ordered, can do fine up to 17-18% active lime, it is worth re-testing this particular part of the plot where the ground pine lives to see if these areas should be preferentially planted with 41B rootstock, which I also have on order, and which can tolerate up to 40% active lime.
It is a good example of how plants can hint at the underlying soil chemistry of a site, but also a reminder that there are very few substitutes for applied chemistry when it comes to getting an accurate assessment.
Meanwhile, these excellent little plants do a good job of preventing erosion on the most exposed part of the site, and represent the first step in a line of succession that will eventually see the whole field return to a mixed grass sward, naturally in between the many vines that will come to dominate the site.
Alongside the ground pine (though not pictured above) is several examples of prostrate spurge (Euphorbiaceae spp.) which is a low, spreading summer-active plant that provides good ground cover and is well adapted to hot exposed surfaces. As with the ground pine, its presence is a direct consequence of the relatively exposed nature of the site.
Woody Perennials and Other Plants
Among the many other plants on the plot are dyer’s croton or turnsole (Chrozophora tinctoria) which is a summer annual and adds broadleaf biomass, and crucially continued rhizosphere activity after most grasses have senesced. I also found one example of black nightshade (Solanum nigrum) which though not an immediate issue has a truly astonishing seed potential, with a single healthy plant being capable of producing between 50,000 and 100,000 seeds per season. The main problem with this plant isn’t necessarily the toxicity of the plant itself, as no livestock will be grazed here, but rather the fact that it creates a biological bridge for pests and plant viruses that could potentially have a detrimental impact on the health of the vineyard down the line. Its presence is a bit of an outlier I think, also occurring in the middle of the main bare patch, as it normally prefers nutrient rich sites. That said, it likely took advantage of the manure distributed this spring and found what it needed despite the environment not necessarily being optimal for it. As soon as identified, it was removed.
As for woody perennials, the Christ’s thorn is quite literally a thorny issue. As mentioned previously, a host of small bushes appeared on the sites where larger plants once stood, drawing energy from the existing root system to create new growth. Though very different in nature to the thistles, these plants would also render the area effectively unworkable if left unchecked, and any new growth had to be removed.
I could go on, listing more of the plant species identified on the site, but I believe this has covered the main ones. There will be a host of others which I have not been able to identify, or necessarily noticed amidst the more dominant ones. What is clear is that nature quickly re-establishing itself on the plot, and quite frankly, doing a lot of the regenerative heavy lifting for me. My job is largely to guide and direct this regeneration in a manner that is conducive to my goals of growing vines, which all in all is a far simpler task than trying to force a number of species that compete with the existing seed bank onto a plot where they do not naturally belong.
The Consequences of Diversity
If you’ve spent time in Greece, or other mediterranean countries during summer, you will not have escaped the continuous drone of chirping cicadas that at certain times of the day dominate the soundscape. What is a pleasant background noise by the house, is a true cacophony by the plot, with what sounds like thousands of cicadas competing for attention in the afternoon heat. Each step sees two or three grasshoppers scatter and jump to the side, and on closer inspection there are little insects of all sorts wherever you look. Clinging to taller straws and sturdier plants like the re-emerging thorn bushes were hundreds, and likely more, Eastern Heath snails (Xerolanta obvia) taking advantage of the cooler conditions off the ground. These heat avoidant snails seal their shell opening with a hardened layer of mucus, preventing dehydration and allowing the snail to enter a state of dormancy, known as aestivation, until the autumn rains arrive. As seen in the photo of the wild carrot above, there were striped shield bugs and I'm sure a plethora of other insects that did not immediately announce themselves including praying mantises of which I saw one, and various spiders. The latter I can be quite sure of as one bit my leg, causing it to swell rather concerningly for a couple of days.
While it is amazing for the soil to have such a broad diversity of plants that can feed the soil microbiome and shape the soil structure with their roots, a major benefit of this diversity is its ability to attract a tremendous amount of different insect species. This diversity is crucial for keeping the population of disease vectors and pests in check. For example, the hoverflies, so readily attracted by the wild carrot mentioned above, are able to aggressively consume crop-damaging pests like aphids, thrips, and small caterpillars. These in turn are food for small birds, bats, praying mantises, dragonflies and spiders. Every insect has its place, and I cannot imagine anything worse for the place, and indeed for the quality of the wine this place will produce, than actively killing off this beneficial diversity with systemic herbicides and pesticides.
Final Thoughts
Left to its own devices nature would reclaim this plot in relatively short order. Like I mentioned above, my job is to guide this regeneration in a direction that aligns with the goals of creating a vineyard, eventually finding an equilibrium where management inputs can be kept to a minimum. A vineyard is by no means a natural environment, but there is no need for its presence to completely overturn, or destroy, the broad spectrum of plants and animal life that keep the local ecosystem in balance.
It is worth noting that while I am astonished by the diversity on my plot, it shares much of its biodiversity with the nearby mountain and surrounding areas. Mount Pangeon, alongside nearby Mount Falakron is considered a key biodiversity hotspot in Greece, and hosts rare, narrow-range endemic plants, including the subalpine flower Centaurea pangea, and hundreds of other distinct vascular plant taxa. While there is no doubt that the undisturbed mountain hillsides will be host to more of these special ecosystems than what after all is an urban-adjacent piece of agricultural land, it remains very encouraging.
One of the more reassuring lessons from the past few months is just how little encouragement the site has needed to begin repairing itself. Much of the bare soil has been colonised, active root systems are once again holding the hillside together, and a complex ecosystem of plants and insects has returned with minimal encouragement. I look forward to seeing how the site will evolve as summer gives way to autumn, and while further interventions will inevitably be necessary to make the plot suitable for viticulture, we are off to a very good start.
What is really nice to see is that the transition of the plot from open meadow to vineyard is imminent. During this visit, 525 lengths of rebar were delivered to Kormista. These are destined to become the individual stakes around which each of the vines will eventually be trained. For the moment they remain behind lock and key in the garage by the house, but once driven into the hillside they will provide the first permanent indication of what this place is going to become. Their installation will of course come after a perimeter fence has been put up, with the primary goal of keeping the goats out.
Much of this project has up until now focused on clearing the land, taking soil samples, and readying the field for the planting of vines, but the arrival of the stakes feels like the beginning of something far more tangible. These are permanent fixtures that will likely outlive the vines themselves. I will discuss the benefits of échalas-trained vines, and why I have opted for this training system over the more common vertical shoot positioning that is used in the area in a future instalment of this series.
There is still plenty to do before the vines arrive next spring, but increasingly, this is starting to look less like a piece of land being prepared for a vineyard and more like a vineyard waiting for its vines.
George, do you have any particular books that you like for researching these wild plants? In our garden - 1/3 acre in Walla Walla county - more than a few of the plants and insects you reference are found. However, to pick one example, spurge is clearly a weed and unwanted. We use a particular, fast-spreading violet as principal ground cover, with a couple of others scattered about for variety. We use only organic products and have a wide variety of favorable insects, birds and bats. How you keep all the Latin names straight is amazing. Good luck moving forward with this project!
Having also written a (admittedly far less researched) article on vineyard ecology I know they might not be the most successful but I’m always fascinated by them. So thanks for this instalment!
An interesting angle I was taught to think of those fast colonising plants, thistles, grasses and legumes is that they can get by without relying too heavily on long term mycorrhizal relationships. Their soil relationships are often more bacterial (and short term) and as a result it may have been for this reason that Asteraceae, Poaceae and Fabaceae species were selected by early plant breeders and can be incorporated into intensive crop rotations that give the soil a battering - thus enabling them to make up a hefty portion of our diets.