Edibles: Putting container crops to the test

With space to spare outdoors, I haven't felt the need to grow crops in containers. Yet I've been urging folks without outdoor space to do it -- to turn their balconies, decks and rooftops into food gardens by growing in pots, baskets and boxes.

Knowing how to make container gardening work, though, is not enough. To be a credible cheerleader for the practice, I need more direct experience. Accordingly, I've filled our sunny back deck with planters and my wife with consternation over what she calls an obstacle course in her retreat space.

For containers, I've relied mostly on scavenged materials -- large plastic tubs that once held indoor shrubs, half-bushel baskets and even a container that used to store cat kibbles. I did buy two flexible plastic Rubbermaid storage boxes measuring 20 inches long by 14 inches wide by a foot deep. Hey, they were on sale! And their lids made dandy saucers for the boxes.

The plant tubs and baskets already came with holes for drainage. To make the storage boxes and kibble container into suitable planters was a matter of a few minutes' work with a drill and a 5/8-inch bit.

What you fill containers with matters. Too much garden soil in the confines of a container quickly turns into concrete, so I limited that component to about a quarter of the mix by volume. My own leaf and coffee ground compost composed another quarter. The remaining half of the mix was mostly potting soil and seedling mix (a finer material than potting soil) and a generous several shovels-full of composted chicken manure and several hands-full of complete organic fertilizer.

This year's winter container crops include carrots, beets, spinach, arugula and a mesclun (baby greens) mix. All, I believe, are hardy enough to come through frosts and temperatures in the upper 20s, even in containers, which don't hold heat as well as a large body of soil. If temperatures dip to the mid-20s or below, I easily can move the containers into the garage for the duration of the cold spell.

The greens are too recently planted to have come up, but

I can tell you how the root crops have fared so far. Once their containers were protected with hardware cloth and bungee cords to discourage excavations by our resident raccoon gang, the carrot seeds germinated

so vigorously I was left with quite a thinning job. The remaining plants already are way bigger than carrots from a much earlier, main garden seeding. Germinating conditions in the containers (mainly the moist, airy soil mix) are to this crop's liking.

For all their vigor, my container carrots would be no match for rust fly maggots. So, in exchange for assurances that I wouldn't make a clutter of her deck, my wife helped me attach floating row-cover fabric to a pair of wire cylinders I cut from an old tomato cage. Now our two pots of carrots shelter under these devices, hopefully safe from the maggots.

The beets germinated respectably, but not like the carrots. Thinning was easy. So far, my lesson with container beets is to plant more seed.

As the cool season progresses, I'll keep you posted on the fate of these crops.