Canadians are looking for new ways to produce, access, and experience food. As we explore alternatives to large-scale, industrial agriculture, two particular movements are gaining momentum in our effort to reconnect to our food: urban agriculture and seed-saving.

By growing food in and around cities, urban agriculture reduces food miles and gives us fresh produce that moves from soil to plate in minutes. Seed-saving lets urban growers cultivate heirlooms that offer a tastier and healthier alternative to the modern varieties now being bred simply for their ability to ship and store well.

Seed-saving is an important part of sustainable agriculture, closing the loop in a farming system by limiting inputs produced off-farm. The more seed that can be saved on a farm, the more sustainable that farm will be—and the same applies to an urban garden. Furthermore, the longer a plant variety grows in one location, the more adapted it becomes to those growing conditions.

Farmers recognize two types of plants: self-pollinating (selfers) and cross-pollinating (crossers). Selfers pollinate themselves; the flowers contain both male and female parts, and the female part is fertilized by the male part before the flower opens. Occasionally a bee can work its way into these flowers and cross-pollinate them, but this happens rarely. These plants, which include tomatoes, lettuce, beans and peas, remain fairly uniform over the years.

Crossers, on the other hand, need to be pollinated by another of the same species; the flowers generally cannot accept their own pollen. In order to keep crossers vigorous, farmers have to be very careful about which plants they let go to seed. Crossers include broccoli, kale and other brassicas, spinach, chard, beets, onions and many more.

Saving seed from selfers is relatively easy—you simply keep the seed and can be fairly sure that you will get the same plant next year. But with crossers it is not so easy, because many belong to large families that can all cross-pollinate. For example, broccoli, cauliflower, many kales, and Brussels sprouts are all the same species and will readily cross-pollinate. So be warned: if you grow them together and save the seed you have no idea what you will get the next year! In addition, crossers require large population sizes for saving seed over multiple years. The smaller the population, the greater the risk of inbreeding, which usually has a negative effect on plant quality.

Because urban gardens are relatively small with diverse crops, it is very difficult to have large populations for cross-pollinating. And because urban centers are so densely populated with both people and plants, it’s difficult to prevent your neighbour’s plants from pollinating yours—after all, bees and pollen do not recognize fences.

So for successful seed-saving in the city, it’s generally better to focus on self-pollinating crops. However, most favourite vegetable varieties are crossers, and the temptation to save seed is just too strong. Here are a few tips:

• Talk to neighbours to get an idea of whether their plants may cross with yours. Also remember that plants only cross-pollinate when they flower, so perhaps a neighbour who’s growing the same varieties will agree to pull them out before they flower. Furthermore, buildings and other physical barriers in the city can prevent both wind and insect pollination from occurring—and there are plenty of buildings in the city!
• Since it is difficult to have large populations in an urban backyard, swap seeds of the same variety with friends to ensure a good genetic mix. You can also bring in new seed every two to three years, adding a new gene pool to your seed variety.

Urban seed-saving adds a whole new dimension to gardening and helps make your yard more self-sustaining. By choosing the right crops for your yard, you could be producing all of your own seed in only a few years. For practical information on seed-saving and seed-trading, see www.bcseeds.org

Chris Thoreau is a former organic farmer and member of FarmFolk/CityFolk’s seed team, a provincial group that informs and directs their Seed Security project. He also studies agroecology at UBC, focusing on urban agriculture, seed security, and soil management. His urban agriculture projects are at www.cmthoreau.wordpress.com