‘Costata Romanesco’: A zucchini that will make you smile

If you like zucchini, I think you’ll love ‘Costata Romanesco.’ If you don’t like zucchini, please keep reading. It may change your life.

I became acquainted with this extraordinary summer squash many years ago, and it’s the only zucchini I plant each year. Will Bonsall, well-known Maine seed-saver, and farming/gardening guru reportedly mused that it’s “the only summer squash worth bothering with, unless you’re just thirsty.” Although its Italian name is beautiful, I will refer to it as CR to save space.

Large zucchini flower
‘Costata Romanesco’ flowers are large and can remain attached for some time.
Two zucchinis
Late-season ‘Costata Romanesco’ fruits.

CR is a stunner with alternating dark green and light green stripes with white flecking, like ‘Cocozelle’ and some other Italian varieties. “Costata” means rib in Italian. Fruits develop 8-10 prominent ribs which give cross-cut slices a unique and fun look. It has a dry, meaty texture, not unlike eggplant, that holds up when sauteed, baked, broiled, steamed, or grilled. It has a distinctive flavor described as sweet, nutty, and earthy. In addition to shredding it for cakes and breads I find it makes the best zucchini fritters (see recipe below). This year, I’m freezing loads of shredded CR.

Grate, bag, and freeze extra-large zucchini fruits.
Grate, bag, and freeze extra-large zucchini fruits.

Tips for getting the most from CR:

  • This is a large plant that can easily fill a 4 ft. x 4 ft. space. Some of the sprawling stems will flop to the ground where they will root, even through an organic mulch. These additional stems increase fruiting and allow the plant to survive a squash vine borer infestation in the main stem.
Crowded garden
‘Costata Romanesco’ plants need elbow room.
Roots from a zucchini plant stem that grew into the soil.
Roots from a zucchini plant stem that grew into the soil.
  • Try planting in mid-June to avoid cucumber beetles and squash bugs. That strategy has worked for me if you also delay planting of cucumber and melon.
  • CR produces large, sturdy male flowers if you are into stuffed blossoms. Even when the fruits get overly big, 12-16 inches long and 3-4 inches in diameter, they remain tender. Larger fruits can be shredded.
  • A variety of bees cross-pollinate the flowers, especially squash bees and bumblebees. Plant annuals and perennials to feed bees through the growing season. Interestingly, one small Cornell University study in 2013 showed that CR was somewhat parthenocarpic (produces fruits without cross-pollination). Of 19 bagged CR flowers in the research study, 58% set marketable fruit without bee pollination.

Saving seeds:

  • CR is open-pollinated. With a little bit of planning seed saved this year will produce an identical crop next year (unlike hybrid cultivars).
  • Avoid cross-pollination with non-CR pollen by not growing any other members of Cucurbita pepo, a species that includes yellow summer, acorn, scallop, and spaghetti squash and most pumpkins. Cross-pollination may still occur if these squashes and pumpkins are growing in neighboring gardens.
  • Or, you can hand-pollinate female flowers.
  • If possible, save seed from multiple fruits and multiple plants. Harvest fruits when they become very large with a hardened rind that starts to turn yellow. Allow seeds to mature inside fruits for 3-4 weeks. Cut fruits open and remove, clean, and air-dry seed at room temperature. Store seeds in a sealed container in a cool, dry location. They will remain viable for 5-6 years.
Zucchini cut in half
Seeds being saved for 2021.

Zucchini fritter recipe

2 lbs. shredded zucchini

1 medium onion finely chopped (can substitute scallions)

2 eggs

1 cup panko

2 tsp. salt

1 tsp. black pepper

1 ½ tsp. turmeric

1 ½ tsp. paprika

Shred the zucchini and either squeeze out excess water by hand or allow it to drain in a colander.

Mix all ingredients and shape into patties. Fry in vegetable oil until brown on both sides. Makes 15 fritters. Serve with plain yogurt.

By Jon Traunfeld, Extension Specialist. Read more posts by Jon.

What to do in the vegetable garden in June

How’s your garden growing? Are you busy planting and harvesting? Here are some tips and reminders for what to do this month.

It’s summer now, at least according to the weather forecast, and likely you’ve put in many of your crops. If not, no need to worry; you still have plenty of time. Here’s some of what can still go in:

  • All the cucurbits (squash, cucumber, melon, etc.) can be direct-seeded or transplanted through most of June and even into July. These plants really like warm soil and warm weather, so planting now is ideal.
  • Beans can be planted into July. Bush beans grow faster than pole beans but you will need several succession crops to get the same yield.
  • On HGIC’s Vegetable Planting Calendar, okra is listed as best planted in May, but given our warm autumns I’d say planting in June is a safe bet.
  • Corn does not need to be knee-high by the fourth of July; it can be a baby sprout then too and still produce fine.
  • This is a great time to transplant sweet potatoes, which love heat.
  • It’s also not too late to put in your tomato, pepper and eggplant transplants.
Eggplants grow in containers; yellow mizuna flowers in the background signal the end of spring

Continue reading

Planting Vegetables in May

Maybe April is the cruelest month (especially this year) but early May can be tough on vegetable gardeners who are raring to go. You’ve got your spring crops in the ground and growing; maybe if you got an early start you’re even harvesting. But what about all those delicious summer veggies? If you’re lucky, you have some tomato plants, maybe some peppers or eggplant; you’ve got bean seeds and squash seeds and more. And you have well-prepared soil to plant them in. But when is it safe?

When can I plant these tomato and tomatillo TREES that I started at least a week too early?

When people ask me this, which they do a lot around this time of year, I usually sound a note of caution. But really, there’s no one clear answer. It depends on factors we have no control over, and it depends on how risk-averse you are. Many of us prefer to put a planting date on the calendar; even better if it’s an easy one to remember. St. Patrick’s Day: plant your peas and potatoes. Mother’s Day: time for the tomatoes to go in. But it’s not that simple. Continue reading