Cucurbits (cucumbers, zucchini and squash) are probably not the first choice for many gardeners when it comes to growing container vegetables. However, the convenience of having one cucumber or zucchini ripe nearly all the time and easy to harvest at your kitchen door makes growing your own container cucurbits worth consideration. Based on our trials programs in 2008 and 2009, there are some excellent varieties that are readily found as seeds at garden centers and in most seed catalogs.
Unlike more standard garden varieties, you may have to hunt around for a greenhouse that grows these varieties or start the plants yourself. Look for varieties that are labeled "compact" or "for containers". Larger garden varieties will produce vines that are simply too long, so will run all over your patio, balcony or fire escape. In our trials, we looked for varieties that have very short internodes (the distance between leaf or flower petioles, or branches, or both), so were relatively more compact. Compared to tomatoes, peppers, and eggplants, the cucurbits take up a lot of space. One enterprising balcony gardener grew his cucumbers on nets attached to his railing and trained the vines onto the nets to keep them from taking over other plants.
Specific advice for growing cucurbits
Cucurbits are really easy and quick to start from seed. It only takes 3-4 weeks from seeding to having a large enough plant to transplant into a container. The only reason to go through the transplanting process at all is to get a jump on the season by growing the young plant indoors. Cucurbits will do just fine directly seeded into 14" pots. Plant two seeds for each plant that you want and then remove the weaker plant after germination.
We found that two plants per 14" pot worked out great. More than two plants per pot crowded each other and, as a consequence, yielded poorly, while only one plant underutilized the pot and soil.
Be very careful when fertilizing cucurbits as they will readily respond to high nitrogen applications by producing lots of leaves with very few flowers. Also under high nitrogen feeding, many of the flowers that do form will abort. Apply a timed-release, pelleted fertilizer after you have the first true leaves following the label directions based on pot size. Follow up with low nitrogen / high potassium fertilizers weekly following label directions based on crop, plant, and pot size. Like our tomato program, we found that a 1-1.5-3 ratio of N-P-K benefited the cucurbits. Our fertilizer had a 9-15-30 analysis.
Cucurbits will start bearing after approximately 45 days depending on the variety and will also get overgrown and worn out quickly. In order to keep the fruit coming, be prepared with new planters started 4-6 weeks after you started your first pots. This second planting should keep going right up to the end of the season.
Picklebush yielded copious amounts of cucumbers that were perfect for homemade pickles
Since container cucurbits will produce vines that overrun the pots, set them on top of another pot that is overturned. This keeps the vines more manageable and produces straighter fruit as they will hang down.
Cucumber beetles will beat a path to nearly any cucurbit by mid-June. Look for spotted or striped slender beetles (dark spots or stripes with yellow bodies), then start a management program. For just a few, try squishing them in your fingers. They are not always easy to catch and like to hang around in the flowers. Through feeding, these beetles will transfer a bacterial disease (Bacterial wilt) that will kill your plants. Since bees are required to pollinate cucurbit flowers, you must be very careful in your timing and choices of cucumber beetle control. None of the current conventional or organic pesticides are bee-friendly. Carbaryl (Sevin) is a very effective non-organic choice and pyrethrum (packaged under many names) is the standard organic choice. Spray at sunset to reduce bee expo-sure and follow all label directions. Liquid formulations are somewhat less damaging for bees than dusts. One choice before the plants begin to flower is to keep the plants completely enclosed with floating row cover. These thin, fabric barriers allow light and air exchange while keeping insects out. Row covers must be removed at flowering or bees cannot pollinate the flowers.
Powdery Mildew on cucumber leaves
Short hardy vines with slender dark green fruit.
Salad Bush cucumber
This All-America Winner produces full-sized, garden-type cu-cumbers on compact plants. Somewhat tolerant of Powdery mildew.
This is a very sweet cucumber that is similar to those grown in greenhouses. Very high yielding and somewhat compact.
Cucumber Bush Champion
Full-sized cucumbers on a compact, bushy plant. Also very high yielding.
Very compact plants that produce large quantities of pickling-type cucumbers. The harder you harvest them, the more fruit you'll get.
Zebra Zuke Zucchini
Summer Squash Hybrid. As versatile as any zucchini, but much more dramatically beautiful. The squash are best when very young, about 7-8" long. High yielding and compact for a squash.
Golden Scallopini Bush
Saucer-shaped, golden colored fruit with scalloped edges. The fruit are very tender and ideal for stir fries when picked young.
Sweet Zuke Zucchini
Sweet Zuke's nutty flavor is tasty both cooked and fresh. Heavy yields of cylindrical fruits on bush-type plants. Relatively compact plants with fast ripening fruit.
Prepared by Steve Bogash, retired extension educator. The evaluation of these vegetables is largely due to the labor of the Penn State Extension, Franklin County Master Gardeners and the staff of the Penn State Southeast Research and Extension Center. Of special note is the work of Hillary Snavely, Summer Horticulture Intern 2009, and Donna Berard, Franklin County Master Gardener.