How To Get More From Your Organic Urban Vegetable Garden: Tips from Philadelphia Green’s City Harvest Program
Cover Crops
While many prefer to completely clear their beds in the fall as part of annual maintenance, try clearing your bed of old plant material, adding your fall application of compost and then planting a “cover crop” or a combination of as winter rye, clover, or hairy vetch. The cover crops prevent soil erosion and make nutrients available to plants. They can also be a money saver because you won’t have to add as much compost in the following seasons. Cover crops build soil structure and winter rye has the added allelopathic benefit of preventing some weed seeds from germinating. Try buckwheat in summer when you have a temporary bare space in your crop rotations; it keeps weeds away, and pulls nutrients from deeper within the soil, and provides great bee forage.
Extend Season
A way to get more out of your garden is to extend your season. The typical growing season in Philadelphia run from April 1 to Oct. 15. We try to push it from March 15 until November or later. We accomplish this by choosing seasonally appropriate crops that can take the cold, utilizing row cover fabric in the cool season and shade cloth in the warmer season. The row cover warms the soil and air space beneath the cover, speeding cool season growth in spring, and extending protection in the fall. It also holds moisture at the soil surface, which quickens germination of seeds. We put cooling shade cloth on cool season crops like spinach in late spring and over broccoli, cabbage and greens when transplanting them in early August for fall production. For true winter season extension, clear your plot in early fall, transplant your fall brassicas like broccoli or kale, and then sow a clover cover underneath. When you are done with your fall harvest, you will already have a beautiful cover crop underneath. You would then remove the vegetable plants in January to prevent pests from overwintering in them, and have an established cover crop covering the soil.
Preventative Organic Pest Control
Good gardeners choose resistant varieties and use physical barriers like row cover fabric to thwart common pests such as the Colorado Potato Beetle or Flea Beetle. Other practices to prevent pest outbreaks include crop rotation, interplanting of varieties and crops, and timing your plantings. Often, removing plants such as summer squash that are past peak production discourages pests. We encourage appropriate watering for the plant’s needs. When watering, think about root systems of vegetables. Onions have shallow roots and need water more regularly. Tomatoes have 4-foot tap roots. Once established, you don’t have to water them as often. Planting flowers, herbs, like dill and cilantro and letting crops go to seed attract beneficial insects throughout the seasons into your garden. It’s important to remember that 95% of insects are beneficial, so fostering diversity in your garden is critical to managing your pests.
Using the Best Transplants Available
The more mature and acclimated (hardened off) your transplants are, the more likely they will thrive in your garden. Often, commercial transplants (think box store) are over-fertilized which gives them a rich, green appearance above the soil level and weak roots below. We tend to trust established family nurseries when we can’t start our own plants from seed. It never hurts to ask your nursery grower about his or her practices!
Perennial Fruit
In order to minimize work and get the most per square foot out of the garden, we plant perennial fruit, including some unusual fruits going back to what was grown here in the 1920s and 30s. We have planted raspberries, blackberries, blueberries, gooseberries, currants, strawberries, asparagus, rhubarb, figs, nuts, persimmons, dwarf fruit trees, kiwis, Jerusalem artichokes (Sunchokes) and other perennials at the PPS garden.
If you have room, plant asparagus, berries, nuts and fruit trees. Perennial plantings and fruit trees are much less labor intensive than raising annual vegetables. Think about what makes the most sense for your garden and your tastes.
National Sustainable Agriculture Information Service
Sustainable Ag Research and Education publications
UCSC Apprenticeship in Ecological Horticulture Websites
Teaching Organic Farming and Gardening
Teaching Direct Marketing and Small Farm Viability
Mike McGrath’s tips listed alphabetically
Johnny's Seed Calculator lets you calculate how much seed to order for a specific crop and row space
Peaceful Valley Farm Supply's fertilizer solution chart gives you products for organic nutrient imbalances
Peaceful Valley Farm Supply's pest solution chart gives you products for organic pest control problems
Peaceful Valley Farm Supply's FAQ section gives you answers to basic organic gardening questions
For more information:
Alan Jaffe at 215-988-8833
Laura Hoover at 215-988-8836
