Costata Romanesco Summer Squash Seeds

Organic, Heirloom

This packet sows up to 5 mounds.
4.16 out of 5 stars
(25 reviews)
Availability: In Stock
'Costata Romanesco' delivers a manageable harvest of high-quality, fluted fruits with complex flavor and firm texture. The striped and mottled skin stays tender even to 18", though in Italy they are picked at 4"-5" with the blossoms still attached. Large production of male blossoms for stuffing.
$3.49 12 seeds

Botanical Name: Cucurbita pepo

Days to Maturity: 52–60 days

Family: Cucurbitaceae

Native: North America

Hardiness: Frost-sensitive annual

Plant Dimensions: 2'–3' tall and 3'–4' wide

Variety Information: Best harvested under 12". Light gray-green fruits with lighter stripes and distinct ribbing. Good producer of male blossoms for cooking.

Attributes: Good for Containers

When to Sow Outside: RECOMMENDED. 1 to 2 weeks after your average last frost date, and when soil temperature is 70°–85°F.

When to Start Inside: Not recommended except in very short growing seasons, 2 to 4 weeks before transplanting. Roots are sensitive to disturbance; sow in biodegradable pots that can be planted directly into the ground. Transplant when soil temperature is at least 60°F.

Days to Emerge: 5–10 days

Seed Depth: ½"–1"

Seed Spacing: 2–3 seeds per mound

Row Spacing: 3'–4'

Thinning: When 3 leaves, thin to 1 plant per mound

Harvesting: Harvest frequently to increase yield; squash seem to get monstrous overnight. While edible at almost any size, seeds are less developed in young fruit, therefore more tender. Using a knife or clippers, cut squash off including some of the stem. By including stem, the fruit is sealed and less likely to mold or dry out. Harvesting Blossoms: Look for male, non-fruit producing flowers that have long stems and harvest just before use (female flowers have a swollen mini-squash at the base of the flower and are on shorter stems).

Write a Review

Costata Romanesco Summer Squash Seeds Reviews

25 reviews

My new favorite!

5 out of 5 stars Jul 20, 2018
I love these Roman courgettes! While I still get plenty of them, they don't seem to go as crazy as "regular" dark-green varieties. They also seem to be a bit slower-growing--they don't turn into baseball bats overnight (we've had a stretch of hot weather after a couple of good rains, which usually makes zucchini grow very quickly). They are very mild-tasting, and delicious. I will definitely keep growing these!
Allison Koster from MN

Interesting variety of squash

5 out of 5 stars Dec 6, 2019
We enjoyed this attractive squash all summer. It produced quickly and lasted a long time.
Bonnie from VA

Few Seeds

4 out of 5 stars May 17, 2020
I am disappointed that in this pack there are only 5 seeds! Otherwise, great company and thank you for the freebie!
Veronique from NY
Owner Response: Dear Veronique, Thank you for taking the time to share your experience. We are sorry your seed packet was short on seeds. A customer service agent will be with you shortly to help with the issue.

Romanescu squash

5 out of 5 stars Jul 5, 2020
Just beginning to produce in my garden and so far they are a very good size and there are lots of blossoms. It looks like a good ratio of male to female so I am hoping for lots of nut bread, sharing with neighbors and delicious dinners.

Great Vegetable, Few Seeds

4 out of 5 stars Jul 17, 2020
This is probably the best zucchini to grow for flavor, though the growth is a little slower than some of my other cultivars. The description says it sows up to 6 hills, which I guess means 1 seed per hill as I only received 6 seeds in my packet, which realistically only make 2 hills.
Katelyn from OK
Owner Response: Hi Katelyn, Thanks for taking the time to leave a review. This packet usually contains around 12 seeds. So sorry about that. A customer agent will be with you shortly.


5 out of 5 stars Jul 30, 2020
These are prolific and delicious, but they get HUGE! I have mine in 5 foot tomato cages (4' above ground( and the main stalk grew straight out and over it. It snapped half through, bit still chugging along.
Kimberly Ridley from CA

Large zucchini!

5 out of 5 stars Aug 25, 2020
I couldn't keep up with these plants! They produced large tasty fruits! They were regularly the size of my calf. Everyone really enjoyed them!
Heather Ambrecht from GA

Romanesco that's Amore

5 out of 5 stars Sep 2, 2020
They're so pretty and easy to grow, and no matter the size you pull them they have the same wonderful texture and tender skin. I'm tending only one plant for space reasons, but this has led to the one issue with it, which is the male and female blossoms don't always sync and occasionally I have to pull apart a male blossom that's closing in order to hand pollinate a female that's ready. Nevertheless I love this squash and will grow it again.
Lynn from IL


5 out of 5 stars Sep 4, 2020
Beautiful and tasty squash. My squashes didn't fair well in a hailstorm so I can't speak well to overall productivity but until it was damaged the plant was growing well in a 10 gallon grow bag. A larger grow bag would probably be even better for this large plant but it's a lovely summer squash that I will grow again.
Gardener 2020 from CT

Seed Order

1 out of 5 stars Sep 27, 2020
I ordered these seeds before you shut down but then you substituted another product which I didn't want. I didn't find the substitution acceptable. I would have rather have not received something I didn't want.
Karl Eser from MD
Owner Response: We have since adjusted our policy to refund when substitutions are not comparable (i.e. organic vs conventional). We are sorry you were not satisfied with this substitution. A customer service agent will be contacting you to help.

Loved this squash

5 out of 5 stars Oct 12, 2020
Over all one of the best I've grown. Very surprised by how long the vines grow. I had vines 10 ft long. The leaves where huge. I placed them in a raised bed which it quickly over took and grew into the next bed. The squash was tender and delish! We plant again next year
nancy woodard from NE

Good enough

5 out of 5 stars Oct 23, 2020
I bought this variety back in august I believe. Planted 1 seed that germinate and grow to be a big monster plant, I'm not a zucchini lover myself, but this plant is still given us the right amount of zucchini's that we need. It's not disappointing. Happy with the outcome.
Leslie from CA

the real deal

5 out of 5 stars Nov 22, 2020
the Costata Romanesco Summer Squash is distinctly different than your regular store bought zucchini. And in a good way. Although hard to find seeds it is well worth the search. The package I grew was true to romanesco's characteristics and germinated quite easily. I recommend this product!
sue from CA

a winner!

5 out of 5 stars Dec 29, 2020
Love love loved these squash. This was my first time growing from seed and, with the exception of one seedling that failed to take off, I was thrilled with the result. Seeds germinated easily and plants were incredibly productive and lasted well into the fall. A minor issue with powdery mildew (I grew in a small raised bed, so probably due to crowding) but this did not affect the blossoms or fruit. Squash are super sweet and tender when picked small with blossom still attached but also very good when they spend more time on the vine.
kara from MA

Excellent variety

5 out of 5 stars Jan 31, 2021
I been growing this variety for past several years. I like that the crops are moderate, the squash gives enough fruits to keep us happy through the summer. Botanical Interests is one of my favorite seed suppliers , I alway buy my seed from Whole Foods, but I should probably look at the website. Anyway high quality seeds, very beautifully packed and never had seed that failed to germinate.
calin sferdean from MI

This is a good summer squash

5 out of 5 stars Apr 26, 2021
Try this variety. Manageable amounts of super tasty zucchini-like summer squash.
Donna from NE


3 out of 5 stars May 2, 2021
Only 6 seeds in the package. Otherwise a great variety to grow.
Emily from WA
Owner Response: Dear Emily, thank you for notifying us of this issue. We apologize you received a packet that was short seed. We happily guarantee our seed and a customer service representative will be with you shortly to resolve this issue.

Very productive

5 out of 5 stars Aug 22, 2021
"Manageable harvest" with lots of male blossoms was not my experience, this squash produced a LOT of fruit for me. Not that I'm complaining. It was very tasty, even my spouse who typically does not enjoy squash liked it. They stay quite tender even when they accidentally get a bit large.
Tessa from CO

Costata Romanesco Squash

5 out of 5 stars Aug 31, 2021
I love the crispness of this squash. I cut in half lengthwise, brush with a little bit of olive oil, and grill cut side down. Delicious. I will order more seeds for me and my neighbor.
Valerie from CA


1 out of 5 stars Sep 14, 2021
Was excited to try these next season. I received four seeds ...one of which looks like it won't germinate due to being just a shell.
Lorena from WA
Owner Response: Hi Lorena, We are sorry this happened. We guarantee our seeds and are always happy to take care of our customers. Our customer service department is just a phone call or email away. They will be contacting you by email to take care of the issue.

The best squash

5 out of 5 stars Sep 27, 2021
Usually this variety is one I plant for quality rather than quantity, however, 2021 was an exceptional year for quantity as well. This squash is so versatile for many recipes both savory and sweet. Even if I find one that has grown to a ridiculous size I don't waste it. Just cut the tough skin off, scoop out seeds, and the flesh is every bit as good as smaller ones. Cannot imagine why people continue to grow those insipid zucchinis when this Romanesco variety has a much better flavor.
Barbara from PA

Mama mia Romanesco!

5 out of 5 stars Dec 5, 2021
I discovered Romanesco zucchini in an Italian market, in Italy, they are the most expensive due to their popularity. That was my motive to grow them. I love the flavor, and I picked them young, I didn't let them get bigger than 6-7 inches. The flowers were good as well. I had to hand pollinate them, but it was worth it. Unfortunately my squash bugs love them too. Some say to delay the planting, as these bugs have 1 generation, and to use Diamatious earth close to the main stem. The fight is worth it. Thanks B.I. for keeping these different varieties going!
liz from PA

viable seeds, interesting vining squash

4 out of 5 stars Feb 6, 2022
Not a lot of seeds, but all viable so far. Surprised by the vining habit. Interesting ribbed fruit. Not powdery mildew resistant.
Mark from CA

5 1/2 seeds

1 out of 5 stars May 19, 2022
I just opened my package to find 5 and 1/2 seeds? Is that it?
Janet from CA
Owner Response: Thanks for choosing Botanical Interests. We are very sorry to hear about the short seed packet that you purchased. This is not the quality that we guarantee our customers, and we will gladly replace this for you immediately. A customer service agent will be contacting you via email soon.

6 Seeds?

1 out of 5 stars Feb 18, 2023
I only have 6 seeds in my 1.5 gram packet
Allen from GA
Owner Response: Hi Allen, Thank you for letting us know and we apologize for this issue. These bigger seeds will vary in weight but we aim to provide 12 seeds in this seed packet. A customer service representative will be in touch with you soon via email.

You May Also Like

This website uses cookies to ensure you receive the best experience. Learn More