Zucchini, Courgette, Summer Squash 'Costata Romanesco'

Cucurbita pepo

Family: Cucurbitaceae (koo-ker-bih-TAY-see-ee) (Info)
Genus: Cucurbita (koo-KER-bih-ta) (Info)
Species: pepo (PEP-oh) (Info)
Cultivar: Costata Romanesco
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Zucchini (summer)


18-24 in. (45-60 cm)


24-36 in. (60-90 cm)

36-48 in. (90-120 cm)

Days to Maturity:

51 to 60 days

Mature Skin Color:


Medium Green


4 to 6 pounds (2 to 3 kg)

7 to 11 pounds (3 to 5 kg)



Disease Resistance:

Powdery Mildew (PM)

Seed Type:

Open Pollinated

Other details:

Unknown - Tell us

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

6.6 to 7.5 (neutral)

Propagation Methods:

From seed; direct sow after last frost

Seed Collecting:

Allow unblemished fruit to ripen; clean and dry seeds

Foliage Color:

Unknown - Tell us

Bloom Characteristics:

This plant is attractive to bees, butterflies and/or birds

Water Requirements:

Average Water Needs; Water regularly; do not overwater

Where to Grow:

Unknown - Tell us


This plant is said to grow outdoors in the following regions:

Emerald Lake Hills, California

Los Angeles, California

San Marcos, California

Thousand Oaks, California

Woodside, California

Hilo, Hawaii

Coeur D Alene, Idaho

Pittsburgh, Pennsylvania

Alpine, Texas

Houston, Texas

Shepherd, Texas

Salt Lake City, Utah

Castlewood, Virginia

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Gardeners' Notes:


On Aug 26, 2019, KevinMiller from Winnipeg, MB (Zone 3a) wrote:

After two years of growing Black Beauty zucchini with OK results (albeit in too small a space), I planted Costata Romanesco seeds indoors this year (April 29), grew the seedlings under a grow light, and transplanted 3 seedlings outdoors on May 30 (zone 3) ... giving each seedling quite a bit of space. Plant growth has been incredible, productivity has been great (10 zucchini per plant as of August 25), and they are extremely tasty zucchini. A+.


On Jul 28, 2016, SWVa from Castlewood, VA wrote:

I had a house guest from California several years ago, and her mother had sent various seed packets with her, all foil-wrapped Parks seeds. They were old by the time I received them, dated for the 2009 season. This spring I decided to try a couple of the packets just to see if they would still germinate. Indeed they did, and I have cucumbers and zucchini in the same patch. When I harvested my first vegetable of the season from that patch, I was unsure what it was. It was in the zucchini area, but it looked a bit like an English cucumber. I thought I would add whatever it was to a green salad that night to celebrate the first vegetables of the season, but I never got that far. I cut into the mystery vegetable and discovered that it was, hands-down, the best zucchini I had ever tasted. I did... read more


On May 19, 2014, elsutor from Penn Hills, PA wrote:

Huge, susceptible to mildew, and I abhor SVB, which adore this plant! Nonetheless, this variety has won me over. It is worth it all!

Absolutely the tastiest zucchini I have ever had!

This year I will be growing it again, monitoring carefully for SVB intrusions, battering flowers, cursing the thing when it gets huge. It does resist SVB and I have cut the worms out with (mostly) success. I am going to try using DE this year to ward off the buggers.

I am tempted to try to grow it vertically with a large tomato support, as well, to conserve garden space, increase air circulation, and to be able to monitor for bugs a little better.


On Jul 28, 2009, BettinaW from Salt Lake City, UT wrote:

I have grown some version of this squash for over 10 years. I get my seeds from Johnny’s and a packet lasts 3 – 4 years. And each year I search for a similar tasting squash without the huge footprint others have already commented on. Without success. I have found no way to control the growth although it is pretty tough and every so often I just hack it back.

It produces fewer fruit than other summer squash but you can let them get larger without losing flavor or having them get seedy. You can stuff and bake them and they freeze beautifully for winter sauces. In a pasta sauce they retain their flavor and crunchy texture. This year I tried a small round squash with a civilized habit but the taste was not there so I planted another hill of Costata. Maybe a 3 month gro... read more


On Nov 15, 2006, JodyC from Palmyra, IL (Zone 5b) wrote:

The name means Ribbed Roman...it was not bred for eating but for the numerous blossoms for battering and frying...it's a delicacy in Italy.Can be grown for a winter squash at about 90 days or a summer squash at about 60 days.Full grown squashes can reach 2 feet..is praised for being tender and tasty even when large.


On Jul 13, 2006, kabocha from Alpine, TX (Zone 7b) wrote:

The only zucchini I want to grow - because of the flavor. Last year I gave it too much manure/coffee grounds and it became too huge with scanty production. I had planted it in a bed and tried to get it to grow up to save space - it definitely did not want to do this - heavy and pendulous, awkward. This year I gave it its own space, less rich food and we have more squash. I notice that it does not get powdwey mildew. A great vegetable - cook with olive oil and garlic.


On Jul 8, 2005, PurplePansies from Deal, NJ (Zone 7a) wrote:

Costata di Romanesco is an heirloom Italian squash. (zucchini). It is said to be the best tasting squash in the world. It is also a prolific producer of male blossoms (for frying/eating etc.). A large sprawling plant. Not compact at all. Easy to grow as other zucchini. I've noticed no problems on mine. Fast maturing as other zucchini as well. Fruits are striped and dark green. :)


On May 26, 2005, QueenB from Shepherd, TX (Zone 8b) wrote:

This is a huge plant with huge squash to go with it. The great thing is that the fruits can get quite large and still be very tender. The only drawbacks that I can see is if you have very limited space to garden since the leaves can be up to 15 in. wide and 18 in. long, and it is a low-yielding variety. Excellent flavor.


On Jan 30, 2005, Farmerdill from Augusta, GA (Zone 8a) wrote:

A 52 day Italian zucchini available from Harvest Moon.