I have always been sceptical of the benefits of companion planting. Declarations such as “carrots love tomatoes” and “beans and onions are natural enemies”, offered without any scientific evidence, drive me to distraction. However, after writing last week about the chemicals produced by walnut trees that can kill susceptible plants (such as potatoes and tomatoes), I decided to take a much closer look at the pros and cons of planting different vegetables and flowers together and whether one plant can have a negative or positive effect on another. As I noted, scientists are taking a serious look at allelopathy, that is, the natural interactions between plants where one plant produces a biochemical that affects the growth of another plant.
I have always found that our spring season is so very short that I am hard-pressed to get the soil prepared, let alone try to get everything planted at the appropriate time. Factor in crop rotation, companion planting and whether the moon is waxing or waning and my brain feels like it is ready to implode!
A review of my gardening books and Professor Google found a plethora of confusing information on the effects that one plant may have on another. Most the advice is based on anecdotal evidence. It seems that many variables can affect the results – for example I have found that garlic and onions react very badly to being crowded. I suspect that the result is due to competition for resources rather than an allelopathic interaction. However the more I learn about plant growth and what is going on in the soil, the more I realize how incredibly complicated it is and how very little we understand.
So I am far from being ready to abandon the concept of companion planting. In fact, I realize that I have long practised variations of companion planting, such as planting of different crops in proximity for pest control, pollination and providing habitat for beneficial creatures, and maximizing use of space.
Interplanting is closely related to companion planting. It is simply combining two or more types of vegetables in the same garden bed at the same time in order to maximize the growing area – I have planted a row of a very-fast maturing vegetable such as radish or spinach between rows of slower growing plants such as peppers or eggplant. By the time the peppers and eggplant need the space the radishes will be long gone.
Aromatic herbs can add to a bug-baffling mix – diversity is a key to a balanced environment. There is lots of evidence that insects are attracted to mono-cultures. It is much harder for them to find their target crop in the midst of a diversity of plants. There are plants such as marigolds, chives, and catnip that repel insects while others such as calendula, borage and dill attract beneficial insects.
I must admit that I prefer a bit more order in my garden but if it works, it is worth trying. I have planted radishes around my squash to deter cucumber and squash beetles – it didn’t deter the beetles, but I had some really great radishes.
Perhaps the best known example of companion planting in gardening lore is that of the ‘three sisters’. The three sisters in question are corn, beans and squash that were planted together by aboriginal gardeners. Many years ago I tried this approach and ended up with a horrible tangled mess. When I tried to pick the beans and the corn I stepped on the squash plants and it was difficult to find the beans in amongst the corn and the prickly squash vines. In hindsight it appears I made a few wrong assumptions. Rather than planting sweet corn and beans for picking fresh it works a whole lot better if corn and bean varieties are chosen that are allowed to reach full maturity and that are then picked and stored as dry beans and corn. The prickly vines and leaves of the squash plants act as deterrent to wildlife such as deer as well as to humans! Also from the perspective of good neighbours the nutrient requirements are different – corn needs lots of nitrogen while beans grab nitrogen from the atmosphere.
The final word on the topic comes from a gardening friend. When I asked her if she believes in companion planting she opined that she enjoys having a companion with her when she is gardening!
The Great Veggie Grow-Off
All nine Lanark communities were challenged on May1 at an event at our new Mississippi Mills Youth Centre garden to grow and donate to their local food bank. Presently all four food banks (Carleton Place, Lanark, Perth and Smiths Falls) take donations of freshly grown produce. They have been asked to weigh and record the community of origin of locally grown donations of food from May 1st until the final weigh-in. Bragging rights will be given to the community that donates the greatest amount of locally grown food as well as to the community with the highest amount of freshly grown food donated per person with the big winner always being our community’s food banks.
This Community Challenge, now in its fourth year, expanded last year to include gardeners in communities across Lanark supporting all four of the food banks in the County. The first two years the challenge pitted the municipalities of Mississippi Mills, Carleton Place and Beckwith, the towns supported by the Hunger Stop, and the results were amazing. We saw an increase in people in these towns growing food and sharing it with others.
A grand total of 10,094 pounds of healthy local produce was donated to the four food banks last year. At the final weigh-in last fall our judge and gardening advisor extraordinaire, Ed Lawrence, was quick to analyse the numbers and announce the winners. Mississippi Mills walked away with (but not as quickly as the previous two years) the trophy for the largest amount of fresh garden produce donated to its Food Bank (3,385 lbs.) and Drummond/North Elmsley got the trophy for most food per capita donated to its Food Bank (283 lbs per 1000 persons). In the final analysis though, it is our Food Bank families that came out on top.
The final wrap-up is again scheduled for Thanksgiving weekend. Please remember to drop off surplus garden produce at the Hunger Stop (aka Lanark County Food Bank). Bring your armfuls of produce to the Food Bank at 5 Allan Street in Carleton Place and make sure that it is weighed and credited to Mississippi Mills. Or you can do as our mayor does – he drops off his extra produce at a cooler in the foyer of the Almonte library. We are very grateful to the library for making this service available as well as to the volunteers who pick up this produce and drive it down to the Food Bank.
The Food Bank is open:
Mon: 5:00 pm – 7:00 pm
Tue: 9:00 am – 1:00 pm
Wed: 5:00 pm – 7:00 pm
Thu-Fri: 9:00 am – 12:00 pm
Try to drop your produce off first thing in the morning if possible.